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Container Soils - Water Movement & Retention IV

Posted by tapla z5b-6a MI (My Page) on
Sun, Sep 23, 07 at 18:36

A thread similar to this has been posted three other times. Each of the other postings have reached the maximum allowable - 150 replies. I would like to preface this post by saying that over the last few years, the thread & subject has garnered a fair amount of attention that has been evidenced by the many, many e-mails I find in my in-box, and has been a wonderful catalyst in the forging of new friendships and in increasing my list of acquaintances with similar growing interests. I welcome these exchanges, which alone are enough to make me hope the subject continues to pique interest and curiosity. Not an afterthought, I should add that there is equal satisfaction in the knowledge that some of the information provided in good-spirited exchange is making a significant difference in some growers' success.

I'll provide links to the previous three threads at the end of what I have written. Thank you for looking into this subject - I hope that any/all who read it take something interesting and helpful from it. I know it's long, but I hope you find it worth the read.

Al

Container Soils - Water Movement and Retention

As container gardeners, our first priority should be to insure the soils we use are adequately aerated for the life of the planting, or in the case of perennial material (trees, shrubs, garden perennials), from repot to repot. Soil aeration/drainage is the most important consideration in any container planting. Soil is the foundation that all container plantings are built on, and aeration is the cornerstone of that foundation. Since aeration and drainage are inversely linked to soil particle size, it makes good sense to try to find and use soils or primary components with particles larger than peat. That components retain their structure for extended periods is also extremely important. Pine and some other types of conifer bark fit the bill nicely and Ill talk more about them later.

The following also hits pretty hard against the futility of using a drainage layer in an attempt to improve drainage. It just doesn't work. All it does is reduce the amount soil available for root colonization. A wick will remove water from the saturated layer of soil at the container bottom. It works in reverse of the self-watering pots widely being discussed on this forum now.

Since there are many questions about soils appropriate for use in containers, I'll post my basic mix later, in case any would like to try it. It will follow the Water Movement info.

Consider this if you will:

Soil need fill only a few needs in plant culture. Anchorage - A place for roots to extend, securing the plant and preventing it from toppling. Nutrient Sink - It must retain sufficient nutrients in available form to sustain plant systems. Gas Exchange - It must be sufficiently porous to allow air to the root system and by-product gasses to escape. And finally, Water - It must retain water enough in liquid and/or vapor form to sustain plants between waterings. Most plants could be grown without soil as long as we can provide air, nutrients, and water, (witness hydroponics). Here, I will concentrate primarily on the movement of water in soil(s).

There are two forces that cause water to move through soil - one is gravity, the other capillary action. Gravity needs little explanation, but for this writing I would like to note: Gravitational flow potential (GFP) is greater for water at the top of the container than it is for water at the bottom. I'll return to that later. Capillarity is a function of the natural forces of adhesion and cohesion. Adhesion is water's tendency to stick to solid objects like soil particles and the sides of the pot. Cohesion is the tendency for water to stick to itself. Cohesion is why we often find water in droplet form - because cohesion is at times stronger than adhesion, waters bond to itself can be stronger than the bond to the object it might be in contact with; in this condition it forms a drop. Capillary action is in evidence when we dip a paper towel in water. The water will soak into the towel and rise several inches above the surface of the water. It will not drain back into the source. It will stop rising when the GFP equals the capillary attraction of the fibers in the paper.

There will be a naturally occurring "perched water table" (PWT) in containers when soil particulate size is under about .125 (1/8) inch.. This is water that occupies a layer of soil that is always saturated & will not drain from the portion of the pot it occupies. It can evaporate or be used by the plant, but physical forces will not allow it to drain. It is there because the capillary pull of the soil at some point will surpass the GFP; therefore, the water does not drain, it is "perched". The smaller the size of the particles in a soil, the greater the height of the PWT.

If we fill five cylinders of varying heights and diameters with the same soil mix and provide each cylinder with a drainage hole, the PWT will be exactly the same height in each container. This saturated area of the pot is where roots seldom penetrate & where root problems frequently begin due to a lack of aeration. Water and nutrient uptake are also compromised by lack of air in the root zone. Keeping in mind the fact that the PWT height is soil dependent and has nothing to do with height or shape of the container, we can draw the conclusion that: Tall growing containers will always have a higher percentage of unsaturated soil than squat containers when using the same soil mix. The reason: The level of the PWT will be the same in each container, with the taller container providing more usable, air holding soil above the PWT. Physiology dictates that plants must have oxygen at the root zone in order to maintain normal root function.

A given volume of large soil particles has less overall surface area when compared to the same volume of small particles and therefore less overall adhesive attraction to water. So, in soils with large particles, GFP more readily overcomes capillary attraction. They drain better. We all know this, but the reason, often unclear, is that the height of the PWT is lower in coarse soils than in fine soils. The key to good drainage is size and uniformity of soil particles. Mixing large particles with small is often very ineffective because the smaller particles fit between the large, increasing surface area which increases the capillary attraction and thus the water holding potential.

When we add a coarse drainage layer under our soil, it does not improve drainage. It does though, conserve on the volume of soil required to fill a pot and it makes the pot lighter. When we employ this exercise in an attempt to improve drainage, what we are actually doing is moving the level of the PWT higher in the pot. This simply reduces the volume of soil available for roots to colonize. Containers with uniform soil particle size from top of container to bottom will yield better and more uniform drainage and have a lower PWT than containers with drainage layers. The coarser the drainage layer, the more detrimental to drainage it is because water is more (for lack of a better scientific word) reluctant to make the downward transition because the capillary pull of the soil above the drainage layer is stronger than the GFP. The reason for this is there is far more surface area for water to be attracted to in the soil above the drainage layer than there is in the drainage layer, so the water "perches".

I know this goes against what most have thought to be true, but the principle is scientifically sound, and experiments have shown it as so. Many nurserymen are now employing the pot-in-pot or the pot-in-trench method of growing to capitalize on the science.

If you discover you need to increase drainage, you can simply insert an absorbent wick into a drainage hole & allow it to extend from the saturated soil to a few inches below the bottom of the pot, or allow it to contact soil below the container where it can be absorbed. This will successfully eliminate the PWT & give your plants much more soil to grow in as well as allow more, much needed air to the roots.

Uniform size particles of fir, hemlock or pine bark are excellent as the primary component of your soils. The lignin contained in bark keeps it rigid and the rigidity provides air-holding pockets in the root zone far longer than peat or compost mixes that too quickly break down to a soup-like consistency. Conifer bark also contains suberin, a lipid sometimes referred to as natures preservative. Suberin is what slows the decomposition of bark-based soils. It contains highly varied hydrocarbon chains and the microorganisms that turn peat to soup have great difficulty cleaving these chains.

In simple terms: Plants that expire because of drainage problems either die of thirst because the roots have rotted and can no longer take up water, or they starve/"suffocate" because there is insufficient air at the root zone to insure normal water/nutrient uptake and root function.

To confirm the existence of the PWT and the effectiveness of using a wick to remove it, try this experiment: Fill a soft drink cup nearly full of garden soil. Add enough water to fill to the top, being sure all soil is saturated. Punch a drain hole in the bottom of the cup & allow to drain. When the drainage stops, insert a wick into the drain hole . Take note of how much additional water drains. Even touching the soil with a toothpick through the drain hole will cause substantial additional water to drain. This is water that occupied the PWT before being drained by the wick. A greatly simplified explanation of what occurs is: The wick "fools" the water into thinking the pot is deeper, so water begins to move downward seeking the "new" bottom of the pot, pulling the rest of the water in the PWT along with it. If there is interest, there are other simple and interesting experiments you can perform to confirm the existence of a PWT in container soils. I can expand later.

I remain cognizant of these physical principles whenever I build a soil. I havent used a commercially prepared soil in many years, preferring to build a soil or amend one of my 2 basic mixes to suits individual plantings. I use many amendments when building my soils, but the basic building process starts with conifer bark and perlite. Sphagnum peat usually plays a minor, or at least a secondary role in my container soils because it breaks down too quickly and when it does, it impedes drainage and reduces aeration.

Note that there is no sand or compost in the soils I use. Sand, though it can improve drainage in some cases, reduces aeration by filling valuable macro-pores in soils. Unless sand particle size is fairly uniform and/or larger than about BB size I leave it out of soils. Compost is too unstable for me to consider using in soils. The small amount of micronutrients it supplies can easily be delivered by one or more of a number of chemical or organic sources.

My Basic Soil

I'll give two recipes. I usually make big batches. I also frequently add agricultural sulfur to some soils for acid-lovers or to soils I use dolomitic lime in.

5 parts pine bark fines
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime or gypsum
controlled release fertilizer
micronutrient powder (or other continued source of micronutrients)

Big batch:

3 cu ft pine bark fines (1 big bag)
5 gallons peat
5 gallons perlite
2 cups lime or gypsum (you can add more to small portion if needed)
2 cups CRF
1/2 cup micronutrient powder (or other)

Small batch:

3 gallons pine bark
1/2 gallon peat
1/2 gallon perlite
small handful lime or gypsum
1/4 cup CRF
1 tbsp micro-nutrient powder

I have seen advice that some highly organic (practically speaking - almost all are highly organic) container soils are productive for up to 5 years or more. I disagree and will explain why if there is interest. Even if you were to substitute fir bark for pine bark in this recipe (and this recipe will long outlast any peat based soil) you should only expect a maximum of two to three years life before a repot is in order. Usually perennials, including trees (they're perennials too, you know) ;o) should be repotted more frequently to insure vigor closer to their genetic potential. If a soil is desired that will retain structure for long periods, we need to look more to inorganic components. Some examples are crushed granite, pea stone, coarse sand (see above - usually no smaller than BB size in containers, please), Haydite, lava rock (pumice), Turface or Schultz soil conditioner, and others.

Al Fassezke

If there is interest, please find the previous postings here:

Posting I

Posting II

Posting III


Follow-Up Postings:

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RE: Container Soils - Water Movement & Retention IV

Al,

While I have not always agreed with everything you have posted, I do have to give credit where it is due.

Without reading your posts I would have never played around with Turface (or even known what it was) or pine barks fines (or even known what 'fines' were). I have played with both and have come to love them.

I also didn't realize that after I watered my houseplants that I could get them to drain faster by tilting them a bit. I don't know that you actually said this would happen, I think you just explained this phenomenon in your water movement threads. I have very few houseplants in any kind of soil these days (preferring hydroculture), but for the few I still have in potting mix tilting them sure does make them drain faster so they stop dripping and can be put back in place.

In other words while I do not agree with everything you have said (but have no serious objections either) I have learned a lot so thank you!

BTW, for those who do not know Al, he is a guy who gets his kicks helping others and has invested his real world monies to do so.

Everything he says, agree with it or not, is the opinion of a well read and practiced person and he is someone who is more than willing to put his money where his mouth is.

In short, he is good people.


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RE: Container Soils - Water Movement & Retention IV

Thanks Al for the new post. I did not notice anything in this post you have not said before, but even for those of us who have read your posts before, repetition is worthwhile. How other wise could going to church once a week be justified? Due to your influence I have changed my cutting mix, although I don't think you ever mentioned it. Using a mix of half and half fir bark fines and Play Ball has greatly facilitated starting cuttings that are not nearly so sensitive to my neglect. Your information opens new doors to experimentation and reevaluation of the way we are doing our propagation. Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by wobur 7/8 Sierra foothill (My Page) on
    Wed, Sep 26, 07 at 10:56

What a great thread this is...I have read it through twice.

In order to take advantage of the increased drainage from partially sinking a container in the soil, how far down does it need to be? Is it a percentage of the size of the pot?

In double potting, how much space should there be between the inside container and the outside one? Is there a minimum depth at the bottom required to achieve increased drainage?

And....Has anyone used "Earthgro Western Bark" as the "fines" in Al's formula?

Thanks. Wobur


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Sep 26, 07 at 14:36

In order to take advantage of the increased drainage from partially sinking a container in the soil, how far down does it need to be? Is it a percentage of the size of the pot?

The soil inside the container only needs to be in contact with the soil below for wicking to occur but this may or may not drain all the perched water, depending on how tightly held the water in the container soil is.

In double potting, how much space should there be between the inside container and the outside one? Is there a minimum depth at the bottom required to achieve increased drainage?

When concerned about drainage only, it doesn't matter how much soil is between the side walls of the two containers, and any amount of soil between the growing pot and cache pot will increase drainage. If a particular soil is used in both pots (growing and cache container) and that soil supports a 3 inch perched water column, there will need to be a minimum of 3 inches of soil between the container bottoms for all the perched water to drain. If, for instance, you only had 2 inches of soil, there would still be 1 inch of saturated soil (a technicality, but it would be 1 inch minus the thickness of the growing pot bottom)at the bottom of the growing pot. Oh, this is funny: You could then add a wick to the cache pot and drain the rest of the perched water, though. ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by amyben 7 Bklyn., N.Y. (My Page) on
    Wed, Sep 26, 07 at 15:15

Oh good, a fresh container soil discussion for the winter! Thank you, Al, for my beautiful flowers and tomatoes. I can't wait to discover what percent of my container mix has been colonized by root systems; I suspect quite a lot based on the size of the plants. But, since it's 87 degrees today and sunny out on the roof, my tomato "tree" is dripping with new, green fruit I am sure will have time to ripen. Hopefully, we'll have some fall temperatures in October, and I'll find out in November..
Amy


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RE: Container Soils - Water Movement & Retention IV

I have to thank you too Al,

As a new gardener I was heavy handed with the watering and your soilless mixes have made a drastic difference in the health of my container plants. In changing over to your way of thinking (re-potting) I discovered many of my previous plantings were either a bone dry pot shaped fusion of roots or a mushy stinking mess in the bottom of the pot. I did, in the past, try many different container soil/compost mixes but never had the success like I have using your mixes.

BTW, after months of looking, I found Turface here on Vancouver Island (http://www.growercentral.com - Evergro in Victoria). If anyone is having a hard time finding it or Playball, just look for a sporting supply wholesale outlet. These products are used on Golf and Baseball grounds...some major garden and landscaping suppliers carry them and as you have stated before Bonsi enthusiasts use Turface, so they may be able to point searchers in the right direction.

Thanx again for sharing your research and experience with us.

Tim


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RE: Container Soils - Water Movement & Retention IV

  • Posted by wobur 7/8 CA Sierras (My Page) on
    Thu, Sep 27, 07 at 11:31

Thanks, Al, helpful info as always... If I then used a wick I would have to raise the cache pot off of the ground by two inches? My anticipated cache pot is a half wine barrel with a 7 year old dwarf citrus in a large inner pot. I am picturing hiring an elephant to help me lift it.....my husband is not volunteering! The Meyer is flourishing since I switched to a version of your mix...it's growth and beautiful green leaves and perfect fruit are amazing!!!


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Sep 27, 07 at 15:59

Oh my! I think I need to take just a second to acknowledge all the kind words by the folks who have posted already. I've mentioned before that I have a hard time accepting any accolades or atta-boys for simply trying to help, and have difficulty believing any praise is even appropriate, but I can say from the bottom of my heart that the thank yous, and especially the relating of how something I might have done or written has helped one of you, all feel very, very good. So I too, am grateful to all of you for at least considering what I say and in many cases, using it in practical applications. I do feel good when I feel I'm helping. ;o)

Wobur - no need to use a wick if the soil in the cache pot is in contact with the soil below (through a hole in the bottom). Essentially, you're employing the earth as a giant wick and continuity of the soil as a bridge between the containers and between the cache pot and soil below is important (if you wish the cache pot to drain, too). See? - no need to secure Simba!

Al


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RE: Container Soils - Water Movement & Retention IV

Hi Al,

First of all, I really need your help on this.
I don't know what I did wrong, but I screwed up so badly with yesterday's soil. I made a batch of soil following some of your suggestions, but I tried to be smart and that where I screwed.

I basically added
3 part pine bark
1.5 part peat (instead of 1/2 part), I thought I was growing acid loving plants
1 part perlite
3 handful of gypsum, (instead of a small handful)
a couple of handful of worm casting
1 handful of bone meal

Now when I was very happy about my work, I try to measure the EC/TDS value and PH of leache, to my big suprise, the EC is over 4000us/CM, I think that's about 2800ppm. I was poisoning my plants, I immediately leach the pot heavily, even this morning, the EC value is still 1600us/CM. Pretty high, considering I haven't ferted yet.

I did a small test, I measured each ingredient one by one, by adding water to it, the gypsum has very high EC value, over 2200 us/CM, everything else is about 240 us/CM, very normal, then I mix them together one by one, the moment I added gypsum, the EC value jumped to over 1200 us/CM. What I am thinking is that I added too much gypsum.

But everywhere I read about gypsum, they all talking about its benefits. Never heard about using too much gypsum.

Thanks

Tao


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Oct 8, 07 at 16:10

You sound pretty knowledgeable & probably don't need my help. BTW - what are you growing? ;o)

I see that you added 3 handfuls of CaSO4, but to what volume of soil. 4000us/CM will obviously reverse osmosis & kill the plants, but 1600 us/CM isn't terrible, after fertilizing though, and when plants are growing well. What is your light source - just curious.

Since you only mixed the soil yesterday, I would double or treble the volume w/o adding additional CaSO4 & see what that does. Are you shooting for something in the 800 us/CM range before initiating fertigation?

I know that was pretty elementary & not a lot of help, but we're operating at the limits of my knowledge & I don't want to tell you something that isn't correct.

Good luck.

Al


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RE: Container Soils - Water Movement & Retention IV

Hi Al,

Thanks for the fast response.

I hope that I am knowledgeable enough not to screw up.

I am growing Gardenia and Osmanthus which is all acid loving. My beloved big Osmanthus tree is over fed by me accidentally. Too much slow release fertilizer plus high temperature. I wanted to save that tree.

I have about 3 - 4 gallon of soil, obviously too much gypsum. Is the gypsum related high EC dangerous to plants?

I did a couple of research on the internet, that's my hobby too. Now I just got a Hanna PH EC/TDS meter, dangerous toy, right? Instead of understanding better, now I just have more questions.

I found that gypsum is actually very solvable under acid condition, contributes to more than about 2000us/CM. Now I am wondering that can we really add gypsum into the soil when transplanting gentle plants. Or we have to add gypsum later with much less volume?

Al, could you do a test if possible? Using the recipe you proposed, and see how much is the EC. I have to nail this down.

Much appreciated.

Tao


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Oct 8, 07 at 21:40

Sorry, but I don't have the equipment for the test - I wish I could help you more.

I can tell you that if the EC level in the substrate solution is too high for the crop being grown, roots will be stressed and may even stop functioning if/when EC climbs too high, regardless of the elemental cause of the high EC level. As the roots are effected, symptoms will first appear on the upper part of the plant and would be first indicated by changes in leaf shape or colors, as certain nutrients become unavailable due to the lack of root function. For example, and since were talking about Ca++ here - as the EC in your substrate solution rises, water up-take by the roots will become restricted. When you consider that Ca only moves in the water stream within the plant, even when a high EC level is caused by the Ca++ ions, Ca (and other nutrient) deficiency symptoms will begin to develop on the youngest leaves of the plant near the top. When you see this, it would confirm there is a problem with the nutrient status or EC level in the root zone.

The EC level in a substrate can actually be manipulated to control plant growth and development. The higher the EC of the substrate solution the more difficult it is for the plant to take up the fertilizer solution from the substrate, so the plant is put under stress. Stressed plants tend to become generative or reproductive (flowers and fruit). When the EC is lower in the substrate, the plants can more easily take up the fertilizer solution through their roots, reacting in a vegetative manner, putting energy into shoot extension and making more leaves.

The conversion factor for the Hanna meter is the lowest of the most popular three and converts at 1 MS/CM (1,000 us/CM) = 500 PPM, which is somewhere near where you would like to be before you fertigate.

If you have nothing planted in the soil, perhaps a vinegar or citric acid flush followed by a fresh water rinse would be helpful.

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks Al,

I leached the plants for about 5 or 6 times, the EC value drop s to about 1200 us/CM, I was thinking what the hell, let me redo the soil.

This time what I added.
3 gallon of pine bark
1/2 gallon of peat
1 gallon of perlite
3 handful of Turface MVP
2 handful of worm casting
2 pinches of bone meal (I have middle sized finger, about 1/4 handful)

mix them together really well, then water again. Catch the leache, you know what the EC value is about 2000us/CM, WTF, what's wrong with me. There is no lime or gypsum whatsoever. Where is the ion from? I mixed the worm casting with water, the EC is about 450us/CM.

What I have been doing for so long was wrong?

Whoever has a EC/TDS meter, please help. Let's win the container garden Nobel prize of 2007.

I am confused!

Tao


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Oct 8, 07 at 22:15

What is the EC value of your water? For testing, are you using the water you would normally irrigate with or deionized?

Al

You might try reasking your question at the forum I linked to below.

Here is a link that might be useful: Professional Gardeners Forum


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RE: Container Soils - Water Movement & Retention IV

Thanks for the reference.

The EC value of my water is about 190us/CM, very soft water indeed.

Tao


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RE: Container Soils - Water Movement & Retention IV

Here is the new update.

I keep flushing my pot for about 10 times, finally the EC value drops to about 500us/CM. That's great for new plants in shock.

That keeps me thinking that after making the fresh soil mix, maybe we should flush the mix really well with clean water until the EC value drops to a reasonable range. There is a possibility that for slight acid mix like mine, once you add lime or gypsum or even bone meal, there is a reaction to release the Ca+ ion. If you don't flush the mix well with water, the EC value going to be very high initially. The value is only going down after about 10 deep watering. Unfortunately most of the time when we transplant, we just water once until the water runs out from the drain, the shocked plant will stay in high EC value soil medium, the water intake is restricted, we water less often, the poor plant will stay in such soil for a very long time. That may explains that why so many new transplants get stunned growth for such a long time.

I am also thinking that the micro-nutrients and all other organic supplements should be mixed after the flush.

Tao


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RE: Container Soils - Water Movement & Retention IV

Al I wanted to tell you just how good my morning glorys did with this mix. I have been growing these for many years. This year thanks to your help they have been apsolutely incredible. I mean even when I have grown them in the ground, by this time even if we have had no frost they would be done, with no buds ready to open. But these in this mix in mid october still have hundreds even thousands of buds waiting to open. But they will never get the chance as we are bound to get a frost any time now. What a show! filix


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Oct 13, 07 at 19:23

I'm really glad you're having good success this year, but it probably has more to do with your hard work and how you've implemented what you've learned. Don't be so quick to give credit away - certainly you deserve it more than I, but thank you so much for the nice comments. ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

yellowthumb,

Unless you are growing gardenias hydroponically, I would take a vacation from using the Hanna meter. How is your gardenia looking?

Because I love gardenias, I read and learned a lot about growing gardenias. I don't grow my potted Veitchii (soilless in high % perlite and pine bark but with compost mulch) by EC measurements, but I'm still successful with them. I killed a few by experimenting and by doing but also successfully propagated from cuttings and nursed a few stunted ones to full vigor. I get feedback from my Veitchii (interpretive analytical) mostly when they are not in bloom by looking at the leave color (or any changes), plant form, and the rate of overall growth and new growth with respect to the known or researched specific ideal conditions and requirements that are preferred by a cultivar, say a Veitchii, with what Mother Nature (temperature and light/shade) and I'm doing (the care taker).

A stunted gardenia (slow to no growth), which I had one to compare with (very fortunate to meet one), is not necessary or strictly a watering problem (excess or low) as you observed or suggested. If a well-drained potting mix is used (managed watering problem), an unusually slow growth in gardenia is commonly and often a problem of higher than desired pH wanted by your gardenia (more alkaline) and thus locking up the needed minors (and even NPK sometimes) creating associated nutritional and micronutrient imbalance. However, an identified nutritional deficiency (or imbalance) isn't always caused by lack of fertility or any one micronutrient but the inavailability of available minors due to inoic interplay. Therefore, if the gardenia has symptoms of manganese deficiencies, the resolution isn't always adding more manganese without lowering the pH of the potting mix or other steps in making the complementary or opposing minerals more available concurrently. Deficiency in one element may be caused by an excess of another, so the resolution has to be comprehensive to be accurate and effective.

Fundamentally and in brief, in addition to using a well-drained potting mix, you will also want to adjust your care and methods base on actual visual observation and feedback from your plant in order to correct or diagnose any problems. The meter will give you added reading and data for some confirmation, but the collection of data still has to be analyzed and make sense collectively to be usable and accurate in context to the plant you are caring for. A universal ideal potting mix does not last and if it exists at all. Keeping the potting mix on the acidic side and maintaining it for gardenias is the first step, and none of the amendements in your current potting mix would correct that if the problem is a staunted gardenia. In the case of a gardenia, you want to use an acid-loving soluble plant food and even add some sulfur amendment to maintain that ideal acidity in the potting mix and counterbalance any alkalinity in the water you use regularly and the organic fertilizers you use in your potting mix. A gardener can also train him/her self to narrow down the most probable cause(s) by researching the symptoms commonly exhibited by a species of plants, compare and contrast those symptoms with yours, and then analyze any change in cultivation methods and enviornmental conditions that made sense with your hypothesis to correct a problem most comprehensively and effectively.


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RE: Container Soils - Water Movement & Retention IV

Dear yellowthumb,

It's very possible that the bone meal and worm castings you are using have sufficient high contents of both exchangeable sodium and soluble salts and made your potting mix both sodic and saline, which are factors in causing impaired plant growth. Excess salts can reduce plant growth by reducing uptake of water and nutrients present in soils. Hence, I would argue that the problem may not be the inclusion of gypsum as you observed due to the high Ca+ reading but a "problem" (a good consequence) of displaced sodium salts caused by the added calcium sulphate. This conjecture (adding gypsum is not the problem) would be consistent with your two nearly identical high readings of EC where the only variable was with or without the inclusion of gypsum, which would further indicate to me that the problem was not the inclusion of gympsum but excess sodium assuming your readings were correct or done correctly and that I understood the facts you presented correctly.

If you can somehow get a sodium adsorption ratio (SAR) to measure the ratio of sodium relative amounts of calcium and magnesium and if the ratio of calcium to sodium is less than 10:1, your potting mix would be a confirmed sodic soil (potting mix), where sodium is present in sufficient high quantities to cause soil structural problems. Hard and crusted when dry and slippery when wet is also very characteristics of sodic soils.

Both the high reading of displaced calcium ion (not necessary always a bad thing; free calcium to displace sodium) and the improved EC reading after high volume of flushing also suggest to me that excess sodium salt is involved (and salinity). The high calcium ion reading as result of adding gypsum (calcium sulphate) would suggest two possibilities: a sign that either there was little or no displacement or binding of sodium (bad), or there was more than sufficient sodium ion displacement (good: the added gypsum is working) where there was excess free calcium cations. However, once sodium cations are displaced and replaced with calcium cations by the added gypsum, there is still one additional factor involved in order to improve the uptake of water and minerals for proper plant growth or mitigate a waterlogged salt-affected soil when high water table (potting mix with good drainage and aeration) is not a contributing factor. The excess salts as well as the displaced sodium cations by the addition of gypsum still have to be leached out by irrigation or rainfall in order to improve a salt-affected waterlogged potting mix, and that's why you saw an improved reading after a ten-plus leaching.

If all I mentioned above are consistent with your measurements and what you shared and not shared, then you would want to add gypsum, use less of the worm castings and bone meal to reduce the sodium salts, or a high volume initial leaching if you are going to continue to use both of your organic fertilizers or in the same amounts.


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RE: Container Soils

But then again, once you saw your plants having signs of stunted growth, you could also try leaching the potting mix or repot your plants by using less organic fertilizer to reduce soluble salts regardless what the readings for sodium or calcium or anything might be to try to mitigate the problem blind. Easier said than done in hindsight I suppose.

It seems that measurements or an exact reading of a soluble salt without specified circumstances or in proper context is still limited in use. A measurement may help if we are looking for something, but it doesn't provide us with all the data needed and can lead us down the wrong path or complicate things just as much when we have no information or data or use and analyze data incorrectly. Would love to know what you think.


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RE: Container Soils - Water Movement & Retention IV

Don't forget your brands of peat and pine bark can also have added fertilizers and soluble salts that would add to your EC reading.


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RE: Container Soils - Water Movement & Retention IV

Hi Legacy,

Thank you very much for your knowledgeable post. I have to admit that I still have lots to learn. But ultimately we are all going to be great container gardeners.

I did a test for each ingredients I use in my mix. Again, my tap water is very soft, about 190us/CM, this is the Ottawa river water, thanks to the hard rock and lots of rain and melted snow. I basically just use each ingredient only and catch the leache, the bone meal is about 380us/CM, the worm casting is about 520us/CM. The pine bark is about 250us/CM. But the gypsum is over 2200us/CM, then I read that gypsum is solvable in water to contribute about 2000us/CM. There is a report in Internet about plant growth in overdose of Gypsum. If you have a salt problem, it will help, but if you don't, then the gypsum will stunt your new repot. Exercise caution when using gypsum. It's not as bad as fertilizer, but it can do its damage.

I don't have much problem with my gardenias, they are fat and easy to grow for me. My EC meter also comes with a PH meter. My gardenia ph value is about 5.5, a little bit on the low end. I have one pot have a reading of 5.0, that's too low.

Thanks again.


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RE: Container Soils - Water Movement & Retention IV

That is very interesting, yellowthumb. I also read probably the same articles about using gypsum correctly either for added calclium without altering the pH or to displace excess sodium, but I didn't have a source referencing gypsum causing stunted growth.

Can you do a SAR? If you are sure excess sodium is not the likely cause and that gypsum is, then what do you think is the cause for the high EC reading in your new second batch of potting without gypsum?


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Also if your plants do not have unusual symptoms, such as stunted growth, then there is no problem(s) to correct or problem even with a high EC reading. Is that possible?

I believe cation exchange capacity measures the availability of negative charged sites to attract positive ions - the amount of positively charged ions a soil can hold. While measurement of EC is important in hydroponics, ECE is relatively stable in soil or potting mix (but can be increased by increasing organic matter content); therefore, the measurement isn't generally used in routine soil testing. Isn't that right?

What is the ideal ECE for you? What are you trying to do, or what problems are you trying to solve?


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  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Oct 22, 07 at 16:30

Legacy and Tao (Yellowthumb). I'll politely ask one of you to please start your own thread where you can continue your discussion without taking over this one, or move the discussion to the thread already started by Tao (link provided). I'm sure the entire forum could benefit from your extensive store of knowledge, and your information will get much more attention and notice if you start another thread instead of piggy-backing on this one. ;o)

The reason for my suggesting that Tao post in the other forum was that the discussion was straying from the subject and that the group of participants there might better help him.

Thank you - I know you'll understand.

Al

Here is a link that might be useful: Other Thread


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RE: Container Soils - Water Movement & Retention IV

Will small roots from this years plants in my raised beds hurt anything? Should I screen them out? That raised bed soil worked great. I know this years container soil won't be as good for next years pots. So I'm going to dump all my pots in a new raised bed. Some of them have perlite some turface. All I have to do is add sand and compost. And they will have alot of roots too. So same question for them.

That long term mix 1 part pine bark, 1 part turface, 1 part sharp sand works great for house plants. My maid of orleans jasmine loved it. Since it drains so fast, my plants never stay wet. Could you water everyday with that mix? Thanks Al. filix


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  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Oct 25, 07 at 22:08

Did you think you got lost in the fray, Felix? ;o)

The fine, dead roots in the raised beds will be broken down by microorganisms into elemental form and be available for uptake by whatever plants you plant in the beds - a good thing. The same holds true for your old container soil.

You mentioned "that mix - 1 part pine bark, 1 part Turface, 1 part sharp sand works great for house plants." You might consider either eliminating the sharp sand (robs aeration> and replacing it so your mix is 2 Turface: 1 bark, or get some LARGE silica (masonry supply store) or pool filter sand (1/2 BB size) and use that instead. The larger particulates will increase air holding ability and reduce the volume of saturated soil in the container just after watering. It's more an aeration issue though, than it is drainage.

Al


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I will remember to maybe double up on the turface. I couldn't find granny grit. So I called up the sand/gravel co. They said their sand was sharp, that's why masons don't care for it. I got some and sifted through insect screen untill it was about BB size to 1/2 BB size. I did find some pool sand. And will give that a try next time.

Getting lost in the fray? I live with three woman,"wife,two daughters" so I'm pretty much chopped liver:) Thanks.


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  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Nov 19, 07 at 18:15

Edencat - if you're still following, and from the other thread:

You said: Would you please give me some examples of what a simple blend using just the redwood stuff with the Turface and/or pumice for my three examples of flower/veggie, more woody bush, and small tree would be, in approximate percentages of each item for each of these 3 kinds of plants? I'll even add in some vermiculite if you disagree with those who think it smooshes down too fast, and you think that it would be good, it is only the perlite that gave me so much trouble. I was really hoping to replace the perlite with whatever is next best to it and still be ok. Do you think that would just be too much of a compromise? Also, how long would such a mix likely hold up, and do you think it would stay wet enough to still work ok with watering no more than once a day as long as it's not too windy or hot?

Here is what my friend who uses the redwood soil conditioner had to say:

"I think that redwood soil compost mixed with a LOT of perlite makes a fairly good soil, but I am not too clear on the longevity. The only complaint I have is that it is awfully light weight with lots of perlite, so wind knocking stuff over as well as blowing it out of pots is a possibility. But it works well for me. The only 2 soils I use are: RSC with perlite, about 50/50 or so, sometimes more perlite; and Turface mixed with orchid bark, maybe 60-70T/30-40b. I will sometimes cover top of soil with layer of bark as a water retainer, and if it gets mixed in I don't care. Also do use 100% Turface in a few. No peat in anything recently."

So, from what you have there, I would try this mix:

For flowers/veggies:
4 parts redwood bark soil conditioner
2 parts Turface MVP
2 parts Pumice 1/8-1/4"
1 part sphagnum peat
dolomitic lime

For the woody plant material:
1 part redwood bark soil conditioner
1 part Turface MVP
1 part pumice 1/8-1/4"
gypsum

I left out fertilizers - we can talk about it if you decide to use these blends. If you have questions about why the change from dolomite to gypsum - it's a pH issue. I'll explain if you wish. If you use gypsum, you'll need to supplement the Mg each time you fertilize, and I'll go over that if you use the recipe or similar.

Skip the vermiculite, please. I use it seldom and only in specific applications. I'm sure I could easily do w/o it - probably you, too.

Good luck - sorry I took awhile getting back to you. ;o)

Al

At 12 is fir bark in 1/4-3/8. The other three around the perimeter are perfect size pine bark from 3 different bags. In the center, is the soil that I use for veggies and the 'pretty stuff'.





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RE: Container Soils - Water Movement & Retention IV

Hi Al,
I'm just now back. Thanks for *all* your info. You sure go to lengths to help! As to things like dolomite and gypsum, I'm assuming these are about minerals. Does it matter that our water is already very hard? It's got so many minerals we have to chip it off the faucets whenever it dries there. I try to use water that came through the shower filter on the plants in order to get rid of some of the chlorine, but it's still just as hard as ever so I'm thinking it doesn't need still more minerals added. What do you think?
Thanks again!
EC :)


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  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Nov 25, 07 at 19:01

If you have a municipal water supply, they should be able to tell you what is in it. Often, Ca and Mg are well represented, but one or the other may need supplementing to keep the Ca/Mg balance appropriate. If you have well water, getting it analyzed might be appropriate. Here are:
Desirable Ranges for Problem Irrigation Water Parameters

�� pH: 5.0 to 6.5
�� Soluble Salts (Conductivity): 0 to l.5 mmhos per cm (1 mmho is equal to 1000 umhos)
�� Calcium: 0 to 120 ppm (1 ppm is equal to 1 mg per liter)
�� Magnesium: 0 to 24 ppm
�� Sodium: 0 to 50 ppm
�� Chloride: 0 to 140 ppm
�� Boron: 0 to 0.8 ppm
�� Fluoride: 0 to 1 ppm
�� Sulfate: 0 to 240 ppm
�� Alkalinity: 0 to 100 mg per liter CaCO3

Notice that the Ca:Mg ratio is about 5:1. Anything in the 3-5:1 Ca:Mg is fine.

Al



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Hello Al,

This is my first post here after just being an anonymous reader for a while. I am hoping you would kindly help a new grower with a few questions. I have a 1' Afghan sapling and will be receiving a bare root arizona cypress and blue spruce sapling from arbor day this month.

I would like to pot these little guys for about a year and then plant them in my yard next year. Can you give me some tips on container size and soil mix? I live north of Austin TX by the way.

Is your basic soil mix recommended for these trees?:

Small batch:

3 gallons pine bark
1/2 gallon peat
1/2 gallon perlite
small handful lime or gypsum
1/4 cup CRF
1 tbsp micro-nutrient powder

I also notice people talking about turface. Do I need to add that to the mix. Also, do I just mix this recipe in a bucket and add water? Thank you for your patience and continued contribution to the promotion of plants and trees.


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  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Dec 6, 07 at 17:51

Hi, Marphtwo! We're all so glad you decided to join us. ;o) I hope you decide to stick around awhile.

Afgan pine, and Arizona cypress prefer a slightly acidic, spare (low in organic matter), very well drained soil, and the Cb spruce is not too picky, so you can grow them all in the same mix. I know you said you were getting saplings, but I think they generally ship bare-root seedlings, so you should probably be fine with containers that hold around a quart to a half gallon, depending on what soil you settle on, and whether or not you choose a container with gas permeable walls - like terra cotta/ unglazed clay or fiber containers, any/either of which which, I would choose.

It's kind of hard to tell you if that recipe will work well unless I knew how large/small the pine bark is. That is pretty important info. You're looking for bark about this size


or smaller. If you can find the PB, the mix you noted should be fine where you are. I think it would be better if you could find Turface, Play Ball, or would be willing to pick up a bag of Espoma's 'Soil Perfector', though, but we'll work with what you know you have available - let me know?

Once you decide on what ingredients you can obtain, and give a description of the pine or fir bark, I'll help you with the mix. What you use for liming material kind of depends on what you choose to make the soil from. I'll help with that & with a nutrient program, too.

Don't worry - it's not as complicated as it sounds - just let me know what you have to work with. BTW - how many trees are you getting (3?), & how much soil will you need to make? If it's only a small amount of soil, and you don't think you can find Turface, Schultz packages Turface and sells it as 'Aquatic Soil'. I think for these plants, it might be worth looking for if you're willing to try.

Take good care.

Al


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Awesome! Thanks for the reply Al. I also meant to say that your original post was really really good. It was just what I was looking for and very scientific yet understandable. I had been looking for an article like that one for a while.

I have been struggling to find out the difference between a sapling and seedling, and based on a dictionary definition of a sapling on merriams webster website, which was: "one not over four inches in diameter at breast height", I just assumed since these are about 1' at most could be considered sapling.

If I went with a half gallon container, how much soil would i need to make? I will be getting 3, arizona spruce, blue spruce, and bald cypress. I already have a 1' afghan pine in a little 2"x 2" x 3" container which i should repot probably.

Alrighty, I will go shopping this weekend and find out what I have access to, though I'm sure I can get just about anything. I know a lot of stores with different stuff. I'll post probably Saturday! Thanks a lot!


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RE: Container Soils - Water Movement & Retention IV

Ok Al I went to two places in search for stuff. I saw perlite, plenty of different CRF and micro nutrients, and they had pine cypress fir and "texas red" bark MULCH. The Pine bark mulch bag was still packed full of pieces big enough like in the picture above even though it was also mulch so i think that might work. They also had lava rocks and plenty of different potting soil. I went ahead and bought the last bag of perlite and 4 3/4 gal. terra cotta pots since they were running out.

Bad news, noone at either store knew what turface was, or play ball, and then they proceeded to ask me what was it used for, and i couldnt answer that question to the best of my knowledge. THey all said they could order it for me though if i wanted. I forgot to look for peat and lime/gypsum.

Hope that info helps. So it seems like I can still get what ever I need through order if I dont find it there.

Thanks again!


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  • Posted by rdak z5MI (My Page) on
    Sun, Dec 9, 07 at 7:53

Hate to butt in here but Al and Harris told me Schultz Aquatic Soil is the same as Turface. They were correct. It's more expensive packaged that way but it is Turface and should be available at many stores. Home Depot had alot of it when I went last week.

Also, at Home Depot they sell contruction gravel in the cement section. A fifty pound bag was about $2.85. The chunks are larger than chicken grit but maybe Al could comment on that type of stone/gravel addition to our mixes if someone can't get granite (i.e., chicken) grit.?

The construction gravel is irregular shape and about the size of a pea. Can't remember if it is the exact same size as pea gravel but it seemed pretty close. (It comes in a plastic bag labeled "Gravel".)

The wife was with me and said "let's try an aloe vera plant" she saw when she was getting Xmas stuff.

I said to myself, let me try the construction gravel on that one.

I made the soil recipe of Al's with the construction gravel in place of the chicken grit and it drains the same. Over the long-term - who knows? But it did seem to give the same basic result when it came to drainage, texture, etc. The stones were larger than granite grit though.

Al: Construction gravel for those who can't get chicken grit? Thanks for any info.


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  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Dec 11, 07 at 16:31

Sorry - I've been away for awhile. ;o)

Marphtwo - the size of the ingredients is important. You want to stay within certain limits, or the soil will drain too fast or too slow. Inorganic particles in the 1/16 - 1/8 size are ideal, while particles a little larger, say 1/8 - 5/16, are better for the bark size. Don't be tempted to buy something just because it's pine bark or anything else unless the size is appropriate.

Don't worry - if you can find the right size pine or fir bark, we can come up with a very good soil, whether you find Turface or not. Just let me know what you find, and I'll help. You may be able to find Haydite or pumice (lava rock) in the appropriate size too. Nothing is carved in stone here. The goal is to build a soil that retains air and water in the right volumes for as long as possible. If we can't make it perfect, we can make it VERY good. ;o)

Turface, Haydite, and Play Ball would all be found at large nursery/landscaping operations or places that build athletic fields, prolly it's most common use.

Rdak - did you give up on the granite already? ;o) If you e-mail me & tell me where you live (city), I can prolly find a source for you, and it's inexpensive, too. Prolly around $5-6/50 lbs.

I don't use the gravel because it has a really wide range of particle sizes, which tends to reduce aeration. It also contains lots of sand, which I would want to screen out (through insect screening) before I used it. Very coarse swimming pool filter sand (silica sand in 1/2 BB to BB size) is pre-screened and a good choice for the 'gritty mixes' I describe if you can't find the granite.

Al


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  • Posted by rdak z5MI (My Page) on
    Tue, Dec 11, 07 at 21:37

No, no Al, I haven't given up on granite grit at all. Just tried some gravel for the heck of it when repotting the wife's new Aloe Vera plant. It drains very well and is doing good so far. (The other two-thirds was turface and pine bark.)

The gravel is about the size of a pea and is irregular shaped. I rinsed them off before using them but the gravel stones weren't very sandy or "dirty".

It was just a test to try different stuff that's all. I can get granite grit easily at the feed store near me for $6.00 per 50lb bag.

I hear you though and will stay with the granite grit if you don't think the pea sized gravel is something we should use. It's just a test for the heck of it, that's all.


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RE: Container Soils - Water Movement & Retention IV

Thanks Al,
The trees should be delivered this week, so I need to gather the ingredients soon. The Pine Bark Mulch I found looks about the size of the lower center pile from your picture. I'm going to look harder for turface and Schultz this week/weekend. IS Turface supposed to be a replacement for pine bark?

So what ingredients should I buy this week? I already have perlite and 4 1/2 gal. terra cotta pots. I can get the pine bark mulch. Can you give me the perfect ingredient list and maybe a backup very good ingredient list if I cant find some of the ingredients. I'm going to hit up walmart and home depot to look for turface and schultz. I think I should find that stuff there.

Thanks again Al!


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  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 12, 07 at 17:13

Oh Golly, Rdak - you needn't explain anything to me (your decisions). I was just chiding you in a friendly way. ;o)

Marphtwo - Turface is a baked clay granule that has tons of internal porosity and surface area. It promotes aeration and holds nutrients well. It is not a replacement for pine bark - it's a compliment to it. You won't find the Turface at a big box store, but you might find the 'Schultz Aquatic Soil'.

If you have a source for LARGE size swimming pool filter sand (1/2 BB size to BB size) , it will fill the same function as the grit, but really, you may not need it in the mix down there, as hot as it gets in summer. You could prolly just sub a little perlite & call it good. It would be great if you could call around to some large nurseries, landscapers, or find an athletic field construction contractor for the Turface (or Play Ball or Haydite) though. It is a wonderful addition to any soil, including houseplant soils.

Al


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Rdak I'm jealous. I cant find granite grit here in maine. All the feed stores have crushed oyster shells. Doesn't make any sense to me , as we are sitting atop a very large granite deposit here in Maine. New Hamshire next to us is the granite state, "not the oyster shell state" :>) filix


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RE: Container Soils - Water Movement & Retention IV

Update!
I should've waited to post until now. I found a Home Depot on the way home (I just moved to a new area) and I got the following items:

10 lb. bag Schultz Aquatic Soil
4 dry qt. Schultz Potting Bark (Western Fir Bark)
1.25 lb. Osmocote
5 lb. Espoma Garden Lime
8 dry qt. Miracle Gro Sphagnum Peat Moss

ALong with the aforementioned 8 dry qt. bag Schultz Perlite and 1/2 - 3/4 gal. terra cotta pots.

How does all the sound? Can you help with the mixing amounts and a nutrient program?

I apologize for all the posts. I really do, I am just really excited about this. Thanks!


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  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 12, 07 at 20:44

Hey Felix - I'm working with a person from Kennebunk right now, trying to find Turface or the equivalent. Are you using it? Where did you find it? How close to Portland or Kennebunk?

Marphtwo - is the bark appropriate in size (see first picture upthread)? Is the peat milled or sifted (very fine)? How much soil do you wish to make (total volume)?

Al


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Yes Al I use it. There's only one place in maine to get it and it's not far from kennebunk. I bought 7 bags of mvp this past spring. I was looking for my sales slip. I think it was in the town of monmouth. About one and a half hours from kennebunk. I called profile they helped me. Let me know if I can be of more help. filix


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RE: Container Soils - Water Movement & Retention IV

The bark looks like the center bottom pile. I believe the peat is very fine, it doesnt say on the bag if it is milled or sifted. Based on your recommendation i bought 4 1/2 gallon terra cotta pots. (They are actually slightly bigger but not much). Is that the info you need? 4 x 1/2 gallon volume?

Here is a pic of the peat moss bag: http://www.jamaligarden.com/pID_18026.asp


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  • Posted by rdak z5MI (My Page) on
    Thu, Dec 13, 07 at 3:58

That is strange Filix.

Al, can Filix use the gravel I mentioned in place of granite grit?

Off topic question: How come I can't get smilies to show up in your posts? All I get is the letters instead of the smilies you are posting?


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RE: Container Soils - Water Movement & Retention IV

marphtwo: One place to look for the 50 LB bags of Turface is the Natural Gardener on Bee Cave Road. BWI companies is a supplier (wholesale distributer) and that is who I get it from for my customers here at Canyon Lake (south of you by 50-60 miles:). Sounds like you have what you need for your current project but if you need more in the future give them a call and ask. If I can help otherwise please let me know.
Happy Growing David


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  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Dec 14, 07 at 9:33

Hmmmm .... I know I had posted, or at least written something that never made it to the thread, so I guess I'll do it again.

Felix - if you could get me a name of the place you found the Turface, I'd be very appreciative and my friend would be thrilled. It's not every day someone drops such an easy opportunity to be a hero in your lap. Lolol ;o)

Marph - it looks like you only need a couple of gallons of soil then? Try this:

5 quarts bark
1 quart peat
3 quarts Turface
1 quart perlite
2 tbsp lime

If you can e-mail me a picture of what you end up with (I'm asking because I really don't know what size bark you have) I can tell you if you need to do anything else before you plant in it, but I doubt you will, as Long as the bark isn't too large.

Rdak - I'm not cracking wise when I say he can do whatever he wants ;o), but if he has something more uniform and w/o the sand, I'd use that first.

smiles & winks are :o) = colon, lower case o, right parenthesis
;o) = replace colon w/semi-colon.

Al


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Sports fields,Inc. monmouth maine 207-933-3547 filix


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  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Dec 14, 07 at 18:10

THANK YOU soo much!

Al


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Your most welcome ! I will have to go up there again pretty soon myself. I'm down to less than one bag. filix


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RE: Container Soils - Water Movement & Retention IV

Ok here is a pic of the new bald cypress in your mix Al! Does it look alright? Its a little dark because I just put some water in it.

Maybe the pots are a little bigger because that amount only filled up two. But the Bald cypress is about 2' tall anyway. The soil covered root is taller than this particular pot. I think im gonna get another pot.

Here is a link that might be useful: pic


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  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Dec 17, 07 at 21:17

It looks good - what did you end up with for a mix? Did you find the Turface?

Al


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I used the Schultz Aquatic soil instead. I couldnt find Turface. I used:

Schultz Aquatic Soil
Schultz Potting Bark (Western Fir Bark)
Osmocote
Espoma Garden Lime
Miracle Gro Sphagnum Peat Moss
Perlite

in the quantities you gave me. About to go pour some more.


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  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Dec 17, 07 at 23:24

I think you'll be very pleased, but you'll note I left the CRF out of the mix because of the time of year. It prolly won't hurt anything, but CRF is very temperature dependent (worse when broadcast on the surface instead of incorporated as you've done, though) & I like to try to make sure it's pretty well depleted by the time plants are over-wintering. You should be ok though, because the soil will be fast. Just make sure that you only water when needed & to flush the soil when you do.

You're keeping the plants outdoors - right?

Good luck! (keep looking for the Turface - it's cheaper when purchased by the big bag.) ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

Yeah, with my trees I had at my parents house, I incorporated CRF into the mix, but for these I only sprinkled a smidgen on the top.

I'll post some more pics later tonight of the other potted trees and mixes.

This mix is a lot different than potting soil thats for sure! I was qa little worried because for one of the trees, I had to mix in (about a quart) some leftover potting soil because I ran out of the mix. But I think it should be ok. Thanks!


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RE: Container Soils - Water Movement & Retention IV

Hello Al!

I loved your original post. I have read many questions and replies from this thread. I am slowly working my way through the older threads. At one point I ran into the kitchen and started a capillary action siphon using a bowl and paper towel. It worked just as it should. I love learning stuff like that. I used some of the information this past year. I am new to composting, so my Florida soil is not very well amended yet, therefore I still plant in containers. But the sun is too hot. So I got the bright idea to build a cold compost pile (shredded leaves) and sink my containers into it. Worked great to moderate soil temperatures, and after reading your post, I assumed it would work great as a wick for the containers also. I had the best year ever. Tomatoes did fine; peppers did fantastic as did the eggplant.

This last year I tried a new potting medium, Metro Mix 500. Its a professional mix for containers. I had some fantastic results. It is about $17 for 2.8 cu ft. so it hurts a little to buy in quantity. So I started looking around for the ingredients you have listed. I am now confused a bit. Maybe you can help. Do I need sterilized/processed pine bark fines? I called a local sawmill and they say they have pine bark fines for $19 a cubic yard. I got excited for a minute, then realized what they are selling may not match the vision I have in my head. Ill have to see it first. It seems that buying in bulk like that might not be what you are suggesting in your formula. I have also called around and found a place that says they sell Turface MVP. Is that something to use instead of perlite?

Also, I plan on trying a homemade self-watering container for a few tomatoes this year. The 24 gallon totes are 18" deep with 4" of that planned for the water reservoir. It has occurred to me that the real engineering of these things comes in determining the right potting medium for the individual container design. An example being that the Metro-Mix that I was bragging about is sold in different series. 200, 300, and 500. I was told that the numbers represent particle size. 500 having the largest grind, as the salesman put it. So just assuming I need 500 series for my self watering container might not be true. I might need a smaller particle size, or bigger. It all depends on how high capillary action can take the water. Does this sound right?

Another thing I am wondering about is the moisture wick I will be using. Assuming a closed system with no plant, and no moisture loss through evaporation, one wick in a far corner will eventually provide a constant moisture level at all container locations at a specific height. The only change in moisture level will occur from low heights to high heights. So for this closed system, I only need one wick, located anywhere in the container floor. Adding a plant, with its root draw, and the evaporative losses through gaps in the container top would be the reasons to consider wick placement, size, and numbers. Does that sound right?

I would appreciate any thoughts or comments. Thanks! :)


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Dec 23, 07 at 15:50

Do I need sterilized/processed pine bark fines? I called a local sawmill and they say they have pine bark fines for $19 a cubic yard. I got excited for a minute, then realized what they are selling may not match the vision I have in my head. Ill have to see it first. It seems that buying in bulk like that might not be what you are suggesting in your formula. I have also called around and found a place that says they sell Turface MVP. Is that something to use instead of perlite?

It doesn't need to be sterilized and it's likely, as long as the pieces are fairly regular in size, that you'll be just fine with the bulk mix. See the pics upthread. Finer than what's in the picture (partially composted pine bark fines) are great, too. I prefer them even, to what's shown. There is less N immobilization when using partially composted bark.

As far as the Turface goes - I use Turface only in soils I want to be more durable than what's required of display containers or veggies. A soil made up of equal parts of Turface, Grani-grit, and conifer bark, will last indefinitely. If I'm going to have the plant around for more than a year or two, I use the more durable soil, if not, if a display container or veggies, I'll use the 5 parts bark: 1 part peat ........ mix.

But yes, Turface is a substitute for perlite, but it has a much better CEC and far greater porosity than Perlite.

I might need a smaller particle size, or bigger. It all depends on how high capillary action can take the water. Does this sound right?

Yes, you're right. You may need to tinker with your mixes to get best results, no matter what they're made of. Turface and rockwool are two ingredients that would increase wicking ability, as will the addition of material of smaller particle sizes. Here though, you need to be mindful of the effect of small particulates on drainage/aeration.

Usually, the higher the number, the finer the mix, though.

Your thinking on wicks is exactly correct.

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks for your response Al.

I have enjoyed this thread. Trying to understand the science behind the methods is quite interesting.


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RE: Container Soils - Water Movement & Retention IV

Al

I would like to repot a bunch of my cycads in the spring. Conifer fines in bulk is extremely difficult for me to get here. Turface is cheap enough ($11 per 50-lb), and coarse perlite is readily available as well.

I was contemplating a 50-50 Turface:Perlite mix, with a little peat added to help lower pH a tad. For fertilizer I would use 5-6 month Osmocote plus with micros, and some dolomite. I would supplement with water soluble nitro fert when they are actively "flushing" new leaves.

Does that seem about right to create a well-drained mix that can safely be watered every day, but won't become too dry if watering is withheld for up to a week during the summer? Do you think a little more organic material is needed to help with water retention?

I recall reading somewhere that the pH of Turface MVP is in the 6.0-6.5 range. If so, is there even a need to amend it with a pH lowering substrate?

x


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RE: Container Soils - Water Movement & Retention IV

Forgive me if it's obvious , but what are the "micro-nutrient powders" used in the mix? I want to try this mix but am not sure about what to ask for.
Thanks in advance,
Mary


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Jan 3, 08 at 17:20

X - if you're comfortable with your macro-nutrient supplementation program, and can supply all the minors, you really don't need an organic component. You could probably just grow in a 3:2 mix of Turface:perlite, or a 1:1 mix of grani-grit:Turface. Adding a little more Turface while reducing the granite or perlite would increase water retention. Screening the Turface through the insect screening and discarding fines (or using for something else, like in hypertufa troughs) would still give good water retention and virtually eliminate the possibility of any significant soil saturation for even a brief time, and might be more appropriate for situations if you want to water daily.

I really like the mix I described in the thread I'll link you to below. It would require that you found some fir or pine bark in suitable size, though (see first photo upthread from here).

Yes, the pH of Turface is around 6 - 6.5. I'm not sure what pH your cycads prefer, but if it's below 7, I would be sure to use gypsum as my Ca source & then include a small amount of MgSO4 in the form of Epsom salts with each fertilizing if your fertilizer lacks Ca and Mg (most do). If they prefer pH north of neutral, then I would use the dolomite.

Hi, Mary - You will probably need to do some searching to find the micro-nutrients STEM (water soluble) or Micromax (insoluble), which are what I use. They are usually only available in 50 lb bags & are expensive at around $60-90 per bag, too. There are many other formulations available that are touted to supply the minor elements, though. I incorporate Micromax into soils when I build them and use STEM in my fertilizer regimen after the Micromax is depleted (usually late in summer or early autumn) or on plants arrived w/o Micromax in the soil. You can contact me if you have trouble finding these or another suitable micro-nutrient supplement.

Al

Here is a link that might be useful: another soil discussion


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RE: Container Soils - Water Movement & Retention IV

Thanks Al

I've been using something easier than Epsom for Mg...Lutz Corp makes Magnesium spikes for Palms, 12-month slow release of 12% MgSO4. They also make Manganese spikes, another important macro-micronutrient for many tropicals.

I don't like to promote other companies, but Hummert Int'l has decent prices on many different fertilizers, including S.T.E.M. and MicroMax


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RE: Container Soils - Water Movement & Retention IV

hello, Al, thanks for restarting this thread. I tried the wicking with a toothpick and was amazed at how much water came out.
sue


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Jan 4, 08 at 17:37

Glad you found it interesting, Sue - the thread and the experiment/technique. ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

Al

Just a follow up...I'm sure I can get bark fines in the spring from a nursery/ contractor somewhere. The real reason I'm a little hesitant to use bark is because some of the cycads I plan to repot are going into big pots (25+ gal), and I intend on keeping them in those pots for probably 5+ yrs. Therefore, I'd rather not have to worry about the compost that would eventually be there.

Turface + perlite will render the mix lightweight making it easier to drag the pots around, with virtually zero decomposition, which is precisely what I want.

And with regards to micronutrients: In addition to the minerals present in the Osmocote, I'm sure a little top-dressing of compost or well rotted manure worked into the top 1-2 inches of container substrate in the spring will not hurt.

I appreciate the help.

x


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Jan 6, 08 at 14:55

I think I indicated you really don't need an organic component in your soils if you want to avoid it, but initially, you indicated your intent to use peat & were contemplating adding more organic material to the mix, which, of course, lead me to believe you did intend to use an organic component in the soil. It sounds like you have everything under control & don't really need my help, but IMO, you'd be better served by using conifer bark (if you do use an organic component) and utilizing a complete source of the minor elements instead of peat, manure, and compost. This, in light of the fact that you intend the plantings for long term and are concerned about composting of the organic portion of the media.

Good luck.

Al


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RE: Container Soils - Water Movement & Retention IV

Hey Al what do you think about useing my dynagrow for the minors? I was going to copy cat your fert program. mg,epsom salt, iron, then use the dynagrow instead of the stem, since I have some on hand. filix


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Jan 7, 08 at 17:13

Well, Felix, the fertilizer supplementation program I follow is based on my irrigation water's pH and the dissolved solids in it, the soil I use, and what I amend the soil with as a Ca source, so what I do may not be exactly the best choice for you. E.g., Epsom salts as a Mg supplement probably wouldn't be appropriate if you used dolomitic lime as a Ca source, but would almost certainly be needed if you used gypsum for your Ca. Also, you didn't mention what Dyna-Gro product you intend to use, so I wouldn't be able to even guess at what might be appropriate.

If you tell me what the soil you are using is made from and the proportions, I can probably tell you what would work well for you. If you know anything about your water supply (pH, total dissolved solids, alkalinity, etc.), it would also be helpful.

Al


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RE: Container Soils - Water Movement & Retention IV

I've been reading some of this continued thread for a while now. I'm a beginner that wants to grow a few container tomatoes and peppers without spending a fortune on fancy container mixes. I'll be using those 18 gallon rubbermaid containers shaded with plywood to keep the temps down when it gets hot.
Al's reasoning and research on soils makes sense so I've decided to try his recipe:
5 parts pine bark fines
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime or gypsum
controlled release fertilizer
micronutrient powder (or other continued source of micronutrients
Hopefully I can locate the pine bark fines in my area.
I'm basically doing the container tomatoes to get an early start and to let my native soil rest. I'm writing this message for any tips from anyone that has used Al's mix for tomatoes?
I've heard one of the problems with container tomatoes is that the soil drys out. I'm willing to water every morning so hopefully that won't be problem. I'm also growing early maturing varieties that I'll probably scrap when it gets really hot in mid or late June. My in-ground tomatoes should be coming by mid-June, though I don't know for sure(only my second year gardening).
Any hints or encouragement? Should I use a plastic mulch to keep mix moist? I usually use seaweed foilar sprays and fish emulsion for fertilizing. With the container toms I'll use diluted 10-10-10 and epsom salts maybe also and also fish emulsion and seaweed for micronutrients perhaps. I guess the main thing with fertilzing is to use it steady, but diluted.

Thanks,

Pete


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RE: Container Soils - Water Movement & Retention IV

Thanks Al. Thats right. I forgot about the dolomite I add to the soil. I could leave that out and add gypsum. I bought some che.Iron. The dyna-grow I have is liquid grow 7-9-5 contains all essential trace elements. I followed your soil mix last year as I think you know, and it was great. I ran out of stem last year and bought some dyna grow for the minors. I like your idea of useing the liquid MG and adding what it's lacking, and feed more often with 1/4 strenth. filix


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RE: Container Soils - Water Movement & Retention IV

I forgot to say my town water is 8.6 ph. But I'm planning on puting in a rain barrel system in the spring. So hopefuly I won't need as much town water. filix


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Jan 7, 08 at 20:55

Hi, Pete. I live in MI, where we normally get killing frosts in mid Sep annually. I planted a cherry tomato, unknown variety, in the mix you're going to use in early spring. I put it in a terra cotta azalea pot that prolly held less than 2 gallons of soil. On Nov 2, I went out & picked a QUART of tomatoes from that plant & it was still loaded with small fruit and blossoms. Because the container was so small, I had to put it in a cache pot for shade/temperature control, and had to water twice each day during warm periods, but it grew like mad! I used 12-4-8 Miracle Gro with a couple of other additives, including some Epsom salts.

I made some comments about organic fertilizers in container culture in this thread, if you'd like to read it. You'll find the comments about half-way down the thread.

If you use the soil you mention, I know the potential for good vitality and yields from your tomato growing efforts is there, as I've witnessed it over & over again. Once you become familiar with the soil & establish a good nutrient supplementation program, I'm sure you'll be well pleased.

Felix - I would use gypsum as a Ca source because of your fairly high water pH, & supplement the Mg occasionally by adding a small amount of Epsom salts to the water whenever you fertilize (1/8 tsp/gal).

Al


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RE: Container Soils - Water Movement & Retention IV

I have read so many messages on these threads I feel like I just got a free vo-tech education. ;-) Al you deserve an award for your ceaseless patience. This has been super useful, thanks so much for all the info.

In addition to my many containers, which I intend to use your mix in this year assuming I can find all the components within driving distance and affordably, I have big 24" deep cinderblock beds, as well.

They're low now as I didn't garden last year, and end of 06 they were low as I previously used a lot of compost which being a little hot to start with, has...composted. They're also filled with weeds so my intent (done with some 20-30 gallon containers so far) is to shovel the top out (with the weeds and their roots) and dump it in my compost bins. I think I would like to make the top 12-16" of the soil in the beds something a lot better (although to be fair, it grows stuff pretty well, but I feel could be improved). Something at least similar to your mix (affordability's an issue).

Doing all this for a few pots seems a bit diff than doing it for 4x16/4x16/4x5/4x8/4x4 (12-16" of top) beds. Like... you know,
(a) they already have soil/compost and frankly underneath the top layer it is probably pretty decent stuff I'm guessing, just not really season-level, but anyway the beds will never be 'soilless' that's for sure, and
(b) that is a LOT of $stuff, and
(c) I am torn whether to consider them purely container because they are separated from the ground, or to consider them beds because I can't just "repot" easily.

Would you have any diff advice for 'containers' when the container is plot-sized and 24" and slightly-tillable?


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Jan 18, 08 at 19:10

It's a bed. Though water can "perch" atop a clay layer, part of what would occupy the perched water table moves horizontally away from the bed (as long as it has a place to flow to). For the remainder of the perched water, and practically speaking, the earth acts as a giant wick & attracts/pulls it (with the help of gravity) from the perched water table. It's much more difficult to over-water a raised bed than a container - especially if soils are similar (not usually a good thing - you can successfully grow in much finer & more water retentive soils in raised beds than in containers.

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by dghays Z10A FL Brevard (My Page) on
    Sat, Jan 19, 08 at 11:36

Al, I'd like to join the fray in a (hopefully) small way. Two things, can you do something else with wicks, for a patio container without double potting?
What is your opinion of the usage of finely ground, somewhat composted mulch, which seems to contain some sand, I get from the county dump? Do you see it as completely undesirable to use in a mix? What would you recommend to include with it if usable?

Thanks for your informative post.

Gary


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Jan 19, 08 at 12:54

If the patio is paved with bricks, a wick left to dangle so the water flows away or is absorbed into the space between the pavers will remove water from the container bottom. If the patio is cement, you'll need to lift the container so a wick can dangle below it for wicking to be effective. For wood decks, a wick dangling between the planking is great. Basically, if a puddle forms that contacts the container bottom or the water does not flow away or get absorbed into the ground, wicking can be only marginally effective, at best. The best thing for your plants is to develop a soil that remains adequately moist between waterings, yet supports minimum or no saturation at the container bottom - w/o using a wick.

The mulch - Unless/until I knew what it was made of, I would consider it unusable in either containers or garden; but then, I'm no fan of sand, compost, garden soil, or a high % of fine material in container soils - they could even cause you to inquire about wicks. ;o) ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

It's much more difficult to over-water a raised bed than a container - especially if soils are similar (not usually a good thing - you can successfully grow in much finer & more water retentive soils in raised beds than in containers.

Oh. So... since I have 12-16" at the top of all my beds and big (21-35gal) containers to fill -- the bottom already has soil from the last 6 years -- would you recommend that I use

a) your mix for containers that is mostly pine fines + spaghum + perlite (and a few other minor things), or

b) just plain old mushroom compost like I used to do, or

c) mix the two together?

I'm just worried that maybe the ingredients for a 'soilless' mix are not necessarily good when mixed with soil (either [c], or simply "the soil that already exists at the bottom of the bed-containers").

I'm just not sure, since you've mostly addressed containers, and others address beds, and so I'm not sure how it overlaps (so to speak) as far as ingredients go.

If I did the mushroom compost again, would it be 'improved' by adding spaghum and perlite? Would it make sense, despite these are a 'container' mix, to either add them or literally to skip soil/compost entirely and just use the 'container' mix in the beds, if I can afford it?

(I feel like somehow I am not asking something clearly enough so please forgive if I'm being a bit redundant.)

Thanks a ton.
PJ


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Jan 19, 08 at 18:27

I'm still a little confused, but the main purpose of the soil discussion is to point out that ample volumes of air in container soils (aeration) is as important as water, light, and nutrients; and that any mix that is durable and provides it is a good mix, as long as none of the ingredients are phytotoxic. You don't need to use the exact recipe I use. I just offer it up because it holds air for a long time & has proven over and over that it's very productive.

Growing in raised beds is almost exactly like growing in the ground. You needn't be worried about using sand or compost in raised beds, as long as the soil isn't mucky & holding onto too much water. A good rule of thumb is to evaluate the soil and ask yourself if you'd be happy if it was your garden soil. If "YES", then you'll do fine.

Water behaves differently in containers than in the earth because of the container sides and particularly the bottom. Most of the physics talked about in the threads previous, the perched water table, still can apply in ground soils, but practically speaking, it never comes into play.

If you're growing in a container with sides & a bottom, this thread applies. If you're growing in a bed, the same principles you'd use in gardening apply. That doesn't mean though, that there isn't valuable lessons to be learned by understanding the difference. ;o)

Does that help, or do you have other questions? You're not being redundant - besides, I'm not doing much gardening right now except indoors. It's 9* on its way to 0* tonight. ;o)


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RE: Container Soils - Water Movement & Retention IV

Thanks for your help.

Yeah, I'm going stir-crazy too, not being able to work on the garden, which is in desperate shape and needs a ton of very serious work before it's even ready for spring planting still. I can wear two pairs of pants, two shirts and a hoodie, with hood, gloves, but if I'm going to freeze my nose off, I still can't work in there dang it!, so I've been sitting indoors waiting for it to warm up.

Besides. This is the only time my garden has no mosquitos at all. Such a shame to lose it. ;-)

I guess one of the problems I've had in understanding, is that I'm not 100% clear on what's best for 'beds', either. Compost, I don't have any good stuff, I get mushroom plant compost usually around Feb. I just feel like that isn't good enough and I should be doing "something" to improve that.

I've been looking at the Ph levels for the various plants, and it looks like Daikon Radish is weirdly high -- 6.5-6.8 Ph preferred. Since I'd like to get the soil for everything else to about 6.1 (a medium that is in the ideal zone for everything else I grow) I'm wondering if I should become a 'container' veggie gardener for more than just a pepper -- is there any reason why root veggies like daikon and carrot and alliums can't be grown in containers?? I never hear of people doing this, I wonder why?

So do people put spaghum or pumice in beds? Or are these things specific just to containers?

PJ


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Jan 22, 08 at 1:05

Mushroom compost is usually pretty hot because of a high urea content & quite high in soluble salt content.

If a plant's preferred pH range is 6.5-6.8, I can promise you that there will be some other limiting factor that will affect growth much more than the soil being 4/10 of a point out of the preferred range. Don't worry so much about pH. There's little you can do about it w/o a good understanding of soil chemistry or professional testing, & you're more apt to cause problems trying to chase a preferred pH than to achieve your goal. If you make sure you have a healthy soil and the right nutrients in the garden, and use a well aerated mix with a sound nutrition program (especially) in your containers - things will grow for you.

Toward the bottom is a picture of the soil in my raised beds after 5 years of service. It was made of something like:
5 parts pine bark
2 parts sphagnum peat
2 parts Michigan (or sedge) peat
2 parts sand
1 part Turface
You can still see the bark, sand & Turface, which lasts indefinitely. We could also figure out a way to incorporate pumice (since you asked after it) by substituting for the sand or even Turface, depending on your climate, if you chose.

You can see it is very rich & has excellent tilth. It's a very productive soil & is quite alive with all kinds of soil organisms. You could leave out the sand, and use a volume of native soil equal to the total volume of the ingredients you add and still have an excellent soil, and you would have less shrinkage over the years, too.



I'm going to have a little surgery done tomorrow, so I might take a few days off, but I'll be back if you still have any questions. I hope you got the answers you needed? ;o)

Take care.

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks a ton for your help Al.

Good luck on your medical-fest! May you be better after.

Best,
PJ


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RE: Container Soils - Water Movement & Retention IV

i would like to use a mix for my houseplants / succulents, this is what i have mixed up so far
28 gallons of
3 parts pine park
2 parts turface
2 parts coco coir
1 part perlite

but now i'm not sure how much crf i need to add?
also how much to add of gypsum or dolomite lime (what's the difference?)
haven't been able to locate micro-nutrients yet
anything else i'm missing or need to change?


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Feb 5, 08 at 23:23

Use 1-1/2 cups of dolomitic lime and 2 rounded cups of CRF for 28 gallons of soil. If you're making soil for houseplants and stuck on using the coir, I would reduce the bark fines to 2 parts and the coir to 1 part.

I'm told you can buy small quantities of Micromax or STEM @:

Southwest Fertilizer
5828 Bissonnet
Houston, Texas 77081
(713) 666-1744

If you get Micromax, use it @ the rate of 1 cup/60 gallons of soil - or 1/2 cup/28 gallons.

If you can't get it through them, contact me off forum & I'll help you.

Al


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RE: Container Soils - Water Movement & Retention IV

al
so i need to add more turface and perlite.
what's the difference between peat and coir?
why would i reduce the bark?
i will check out the contact for micromax.

thank you


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Feb 6, 08 at 0:49

Coir & peat have a near identical water retention curve. They both hold just over 90% of their volume in water at saturation, and begin holding water so tightly it's unavailable to plants at about 30% saturation. Coir is easier to rewet when it drops below 30% saturation, which is the point where peat begins to become hydrophobic. Coir has a shorter fifer length than peat and compacts a little easier, also exhibiting a little less aeration. The pH of coir can also be a little problematic, coming in usually at around 7. If you're using coir in the soil instead of peat, you might be a little better off to use gypsum as a Ca source rather than dolomite & then supplement the Mg (your fertilizer may well be missing Mg) with the addition of Epsom salts each time you fertilize.

I suggested you use less bark so it would increase the mineral component of your soil, which will increase the longevity. We often allow houseplants to remain in soils far longer than we should. To combat this tendency, a longer lasting soil is the better choice.

Truthfully - I think that you would be very happy with a soil made from (by volume) equal parts of Turface, crushed granite, and pine bark. I grow all my woody plants & houseplants, including succulents in some variation of that blend and it performs wonderfully.

Al


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RE: Container Soils - Water Movement & Retention IV

I don't see a need for adding dolomitic lime in your mix to grow succulents especially if you are using coir. More often than not and with the pH and composition of minerals in the water from many municipalities and unless you are growing plants that thrive in added alkalinity and constant high pH, gypsum is a more user-friendly and suitable source of needed calcium and sulfur (or epsom salts for magnesium) if these macro- and micro-nutrients are not already supplemented regularly by your fertilizers (soluble or CRF) or if your plants are showing symptoms of need. Follow mnaufacturer's instructions when using gypsum. Generally, there is little harm in overusing gypsum but there is no need to do so intentionally, either.

You also don't need the pine bark (or use less as suggested) if you are using coir; the mix will most likely be too wet with both bark and coir. You want more of an alpine mix for succulents usually, which is 1:1 (grit and compost) where Turface and perlite would be the subsitutes for grit and coir would replace the compost component. I would mix an equal part of coir and perlite (w/ Turface if you want) as a starting potting mix for your succulents. Check the roots of the succulents periodically to see the root condition and growth and amend and fine-tune your potting mix until you find a good mix of aeration and water retention for healthy root growth for your local growing conditions that is also manageable to you to maintain as well.

Watering and fertilizing in coir is different than working with a mix of bark/perlite or Turface. There will be some adjustments working with coir (or any new medium) because how well coir holds water as well as air around the roots even when the coir appears to be very dry on top. Some even argue that special pretreatment of coir and fertilizers should be used to maximize the benefits of using coir. These recommendations may not be entirely true but partially true since we know quality of coir differ from brand to brand and batch to batch (as all soil amendments do). I'm just starting with coco and CHC mixes myself but I'm not growing succulents (yet). Others may have additional and more direct experiences about watering and fertilizing succulents growing in coir or how they take care to minimize compaction of coir.


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RE: Container Soils - Water Movement & Retention IV

i found micromax locally. i am going to try the turface / granite / bark mix, but instead of granite they had utelite would this be equally as good?
if i make about 6 cubic feet of this how much osmocote (18-5-9)/ micromax? would i add dolomite lime/ gypsum to this mix?
thank you


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Feb 8, 08 at 15:09

The Utilite 'fines' would be approximately equivalent to Turface MVP and would be good for use in your soil as a Turface replacement (I would screen over insect screen & discard the fines/dust if you find it too fine). The other grades would be too coarse or too fine. If you cant find the granite, try:
3 parts Turface
2 parts appropriate sized bark
1 part perlite.

Use the gypsum at 1/2 cup/cu ft or 3 cups for a 6 cu ft batch - use Osmocote at 2/3 - 3/4 cup/cu ft or 4 - 4-1/2 cups for the 6 cu ft batch - use Micromax @ 2 tbsp/cu ft or 3/4 cup for the 6 cu ft batch.

Once you have a batch of basic soil mixed, it's very easy to add another handful of this or that to suit individual plants. I think you'll be thrilled to have developed your own soil that you can rely on to perform the same way, every time you plant in it. There is much to be said for consistency. ;o)

Take good care.

Al


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RE: Container Soils - Water Movement & Retention IV

My favorite book for choosing plants here in northeast TN is "Tough Plants for SOUTHERN GARDENS" written by Felder Rushing. He has a container soil recipe that I was going to follow this year. It looks like his recipe is similar to Al's mix.

Felder's Personal Potting Soil Recipe
1 part cheap potting soil* (I assume he means potting mix)
1 part finely ground pine bark mulch.

He states: The bark allows good water and air penetration; the potting soil* holds moisture and nutrients.

Since potting mix contains peat, perlite, and a CRF, I'm thinking that with the addition of pine bark fines this recipe is very similar to Al's mix - except for the garden lime and micro-nutrients. My questions are pertaining to these two ingredients.

I am having a difficult time finding micro-nutrients, and since I'm lazy, I'm wondering how vital they are. Can I get away with leaving it out of the mix for my tomatoes, peppers, and lettuce?

Does the lime wash away as you water, and if so, is it added back again along with water soluble fertilizer?

Other general questions:
How often should I fertilize with that water soluble blue chemical stuff (I hate using chemical fertilizer but figure it's necessary in a pot since compost and worm castings aren't good in there), and how dilute should it be (I'm thinking 1 tsp per gal of water)?

I used landscape fabric to keep from losing soil out of the drain holes, but now I can not use a wick. Is a wick necessary with this mix (I am using Felder's mix with the addition of lime)? Can I just tip the container after watering to reduce the PWT? Will it be possible to tip a 5 gal container with a full grown determinate tomato plant inside?

Last fall I planted Heavenly Bamboo (Nandina), Green Giants, and Pyramidalis Arborvitae. I was going to position my containers in the area of some of these new in-ground shrubs/trees to cut down on travel time when I water. Will the drain off from my containers hurt these plants?

Thank you for your time.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Mar 15, 08 at 16:13

The mix recipe you mentioned is very close to what I grow in, and it should be excellent. Personally, I might add a little more bark than that, and some additional perlite, but that's my preference. The recipe I offer is a starting point that I feel will fit most growers well. You should feel free to tinker with it and adjust it to fit your needs as you see fit. What I try to leave readers of the thread with is the idea that long term aeration, for as long as you intend to keep the planting in the same soil, should be your primary concern. Use the most durable ingredients you can find, and mix them in the proportion that allows the soil to hold the right amount of air and water, and you will find it very hard to fail - your efforts more rewarding. You don't need my blessing, just use what you want from my writings as a guide and discard the rest. ;o)

Since potting mix contains peat, perlite, and a CRF . . .

You cannot depend on the fact that they contain a CRF, unless they say they do; and, since CRFs are expensive, you can usually be sure they contain only enough to allow them to say they are in the mix.

I am having a difficult time finding micro-nutrients . . . I'm wondering how vital they are. Can I get away with leaving it out of the mix for my tomatoes, peppers, and lettuce?

No, in container culture, you must include the minors or growth will be retarded and deficiencies will occur, and you cannot depend on the soil to deliver them.

Here is a summary of Liebig's Law of Limiting Factors: It states here are 6 factors that affect plant growth and yield; they are: air water light temperature soil or media nutrients. The most deficient factor is what limits plant growth and increasing the supply of non-limiting factors will not increase plant growth. Only by increasing the most deficient factor will the plant growth increase. There is also an optimum combination of the factors and increasing them, individually or in various combinations, can lead to toxicity or physiological irregularities for the plant.

Most soluble fertilizers contain NPK in varying ratios. Few contain any Ca or Mg, which are VERY important secondary macro-nutrients. These will be incorporated into many or most commercial soils in varying amounts because they are used to adjust soil pH to around 6.5. If you are adding bark to the mix, you'll need to add more dolomitic lime. S is usually not a problem in bark-based container soils, but you will need to include a source of Fe, Mn, and Zn. Check your fertilizer label, as many fertilizers contain these elements, leaving you only the Ca & Mg to worry about, which are very easily supplied with the dolomite I mentioned.

Does the lime wash away as you water, and if so, is it added back again along with water soluble fertilizer?

Yes, it is leached from the container, and how quickly it is leached depends on the media pH and irrigation water pH. If you incorporate 1/2 cup per cu ft into damp soil when you make it entirely from scratch, or 1/3 cup per cu ft if you mix 50/50 with a commercial soil (this is assuming it was pH adjusted @ production with a liming agent) it should last the whole grow season w/o replenishing.

How often should I fertilize with that water soluble blue chemical stuff . . . and how dilute should it be (I'm thinking 1 tsp per gal of water)?

How often you can fertilize depends on your soil and watering habits. If the soil is free-draining & you water so at least 10-15% of the water applied exits the drain hole, you can fertilize at 1/4 the rate recommended on the package at every watering when temps are below 65* or above 80* if you wish. If temperatures are between those numbers, you can fertilize at 1/2 strength at every watering. During the summer, I use MG 12-4-8 or 24-8-16 on average about every other week at half strength. I don't have time to be as precise as I'd like to, but if I did, I'd fertilize weakly weekly @ 1/4 strength.

I used landscape fabric to keep from losing soil out of the drain holes, but now I can not use a wick. Is a wick necessary with this mix (I am using Felder's mix with the addition of lime)? Can I just tip the container after watering to reduce the PWT? Will it be possible to tip a 5 gal container with a full grown determinate tomato plant inside?

I can't tell you if a wick is a good idea now or not, w/o looking at the mix & how much water it holds. If you're growing in a 5 gal, it likely would help until the roots have colonized the container bottom. You can cut a slit in the fabric & insert a wick, or remove it entirely, so you can be sure there is contact between the container soil and the earth. This will allow the earth to act as a giant wick & it should remove all or most of the perched water - depending on how tightly it's held.

Tipping will be effective while the plants are establishing. After they are established, they'll be thirsty buggers & will likely not need the extra water removed, unless you've over-potted.

Last fall I planted Heavenly Bamboo (Nandina), Green Giants, and Pyramidalis Arborvitae. I was going to position my containers in the area of some of these new in-ground shrubs/trees to cut down on travel time when I water. Will the drain off from my containers hurt these plants?

No - unless you're watering with a herbicide. ;o) It's much more likely that the fertilizer leachate will help fortify the young plants as they establish.

Al


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RE: Container Soils - Water Movement & Retention IV

"If you incorporate 1/2 cup per cu ft into damp soil when you make it entirely from scratch, or 1/3 cup per cu ft if you mix 50/50 with a commercial soil (this is assuming it was pH adjusted @ production with a liming agent) it should last the whole grow season w/o replenishing."

Thank you. That is what I needed to know.

"You can cut a slit in the fabric & insert a wick, or remove it entirely, so you can be sure there is contact between the container soil and the earth."

Duh! I should have thought of that.

"It's much more likely that the fertilizer leachate will help fortify the young plants as they establish."

That is what I was thinking, but wanted to make sure.

Thanks


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RE: Container Soils - Water Movement & Retention IV

Hi Al, I am new to gardening, but I have read your threads on soil and or fertilizer. I am always interested in the scientific part of everything. :-)

I have a simple question: where can one buy pine bark? I just looked in my garage and found two bags of "pine bark mulch" that I bought from Home Depot or Lowes? Can I use those for the soil mix?

Another question is not related to soil, but I don't know where my zone is. Most part of MI is zone 5. There is a small area near Detroit that is zone 6. I am in Canton, MI. I am not sure if I am zone 5 or 6, but you seem to be close, so I thought I would ask.

Well, the question is not just to know the zone number but I would like to know the last frost date. May I ask where you are and when is the last frost date that you use?

Thanks in advance!


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Mar 17, 08 at 10:09

Scroll upthread to the pictures of what is most appropriate for container soils. I like a really fine, partially composted bark best, but the products in the pics works just fine. If you read the posts, you'll see that I found it at places like Home Depot, Meijer, a local nursery, etc. When I find the product I prefer, I usually stockpile it so I don't have to bother looking again for awhile, but I've really never had a problem finding it.

You're a cool 6 (6a) where you live, Dave.

I live in the crotch of Michigan, at the bottom of Saginaw Bay. ;o) I don't really use a last frost date. I never plant bedding plants (in the soil) until 3" soil temps are 55* (you'd be past last frost then). I usually build my containers after May 15. I have so many display containers, plus all the stuff I grow as bonsai & potential bonsai, that I sure don't want to be moving them in & out to protect from frost, so I watch the weather & make sure that there is little (no) danger of frost between May 15 - Memorial Day. I figure that after Mem Day, all is pretty safe, but did I ever show you my hail pictures that happened on Mem Day that just about wiped out every container I'd spent the entire weekend building? Lol ;o)

BTW - charts vary a little, but the Farmer's Almanac lists May 13 as your last frost date.

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by jodik 5 Central IL (My Page) on
    Mon, Mar 17, 08 at 18:52

Another very good read, Al! I learn so much reading your posts, and I know you're right, but it blows the lid off a lot of things I've been taught over the years! I just have to re-adjust my thinking!

I've always used some sort of "drainage layer" in containers, whether it be gravel or charcoal... at one point, I stopped using coarse materials and began placing coffee filters in the bottom of pots, just to cover the hole and keep the soil inside the pot. It eventually rots away, but is useful at the time of planting. Is this acceptable, or should I be using little circles of screening?

As an added note... I'm not really sure why, but I went back to using charcoal as a bottom layer... I was having root rot problems with the medium I was using, and for some unknown reason, began to use a bottom layer once again, after changing my medium. I'm a blonde... what can I say?! LOL!

Now that I'm experimenting with your medium, I find it to be exceedingly well-draining, and my bulbs seem to agree... the ones that are in it are doing well!


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Mar 17, 08 at 21:01

Hi, Jodi. ;o) I know you use a drainage layer from your posts, but here's what I know about their effectiveness as they specifically relate to drainage: They don't work.

Now, I better soften that a little, because I know there are experienced growers who contribute here regularly that use them (including you), so I'll expand a little.

From geologic applications of physics, and from lab experiments, we know that water will perch in a substrate that is comprised of particulates that support a PWT and is situated above another substrate that is comprised of particles greater than 2.1x the size of the upper layer. Using the popular packing peanuts, gravel, large stones, broken pot shards, etc., does not aid drainage. It simply raises the PWT higher in the pot.

Imagine that you have a soil that supports a 4 inch PWT and you use it to fill a 10" deep pot to the rim, you'll have 4" of saturated soil at the bottom of the pot, and 6" of soil that is well-aerated. The top 6" will support good root growth, but before the roots can penetrate into the saturated soil, the excess water will have to be used by the plant or evaporate. As this occurs, the soil becomes hospitable to roots. When you water next, the soil becomes saturated again and the roots must endure another protracted period of anaerobic conditions. Roots begin to die within hours of being deprived of air, beginning with the finest and most important roots first. When air returns to the soil, roots begin to regenerate again.

This type of soil with a PWT sets up a cyclic death & regeneration of roots, which is very expensive to the plant. The energy used to regenerate dead rootage could have been directed to increased biomass or more flowers/fruit. If you try to compensate by watering more carefully, salts from irrigation water & fertilizers build up in soils, creating another set of difficulties to overcome.

Now, lets imagine that we add a 3" drainage layer of packing peanuts under the same soil. Since we already KNOW it will not help to drain the soil, we can see that we will have 3 inches of packing peanuts with lots of air interspersed between the material. Then, on top of the peanuts, we will have (the pot is 10" deep, remember?) 7" of soil to grow in. But wait - the soil has a 4" PWT, so the bottom 4" will still be saturated with perched water, which will essentially give you 3" of soil to grow in until the plant uses the 4" PWT or it evaporates. You also have the same cyclic root death/regeneration.

To be fair, the drainage layer can have a favorable effect. It does effectively reduces the total amount of soil in the container, thus reducing the total volume of water held in the container, which allows air back into the container faster. However, you should note that is not because it was effective at causing the water to drain, it only reduced the soil volume in the container.

Plants like huge volumes of soil to stretch out in. They don't like cramped conditions. If they did, root masses of our garden plants would all be neat little balls or cubes. The problem is, when we use the peaty, heavy soils, we can't use large containers. We are always fearful of 'over-potting' and root rot because our soils stay wet too long. We even try things like adding the peanuts to the soil to "drain" the water (we already learned what really occurs), but that only reduces the amount of soil available to the plant.

I'm not here to throw stones at the practice of adding drainage layers. It can be useful to lighten a container or reduce the volume of soil it takes to fill a container. They just don't drain containers of perched water.

I address this PWT issue each time I offer a recipe for a soil blend. Through geology/physics, we also know that as soil particles get larger, the PWT diminishes, until finally at a particulate size of 1/8" diameter, soils can no longer hold any perched water - it's physically impossible. That is why I choose pine bark as the primary component over peat. A soil with larger particles negates the need for worry about drainage issues & allows you to grow in a homogeneous mixture from top to bottom of the container. I find that to be much preferred to using any drainage layers that reduce the soil volume.

Additionally, once you add the peanuts, you are pretty much locked into a planting that is incapable of holding additional water when the planting has matured & is needing the additional water a higher volume of soil would hold. Instead of using a drainage layer that only reduces the soil volume, why not grow in a larger volume of soil and use a wicking technique to effectively drain the excess perched water. You get several benefits, two of which are: A) You get to grow in a larger volume of soil that is free of saturation, so you eliminate the energy drain of cyclic root death/regeneration. B) You can later adjust the water holding ability when the planting has matured by simply removing the wick. This allows water to remain in the PWT of the matured planting, but now, because the roots have fully colonized the container, the plant quickly uses the water in the PWT and allows air back into the soil before root death can occur.

Was that a rant? ;o)

Jodi - it doesn't matter what you cover the drain holes with, as long as it doesn't impede drainage. I use either a 1/8" mesh plastic screen from the hobby store (sold for needlepoint applications) or insect screening I've purloined from work.

About the charcoal. I use it in my shallow plantings (like 1-2" deep) - mostly bonsai or slab plantings - where I have to use a finer soil (to hold more water). The finer soil combined with shallow container depths means I can have a PWT that occupies a very large % of the soil. The charcoal really helps eliminate rot issues, so I know it would be helpful for your bulbs.

Take care.

Al


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RE: Container Soils - Water Movement & Retention IV

So much information to take in at once :)

Tapla,

I have a few terrariums that I have made using Miracle-Gro potting soil. Could I use a mix like yours above or even the 2/3 organic mix you talked about in the "A soil discussion" post? I really like the idea of the 2/3 organic because I will almost never need to change the soil from the sound of it.
I have ferns, begonias, african violets, and various small house plants. I also have various types of true moss and selaginella, which I know like the more acidic side.

Sorry if you have already talked about this in another topic. There is so much to read and so little time ^^

Thanks for the great reading!

Ross


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Mar 18, 08 at 9:15

Thanks for the kind words, Ross. ;o) I think that the mix I use for succulents would probably serve you well in a terrarium. Here's a part of a post I left on someone else's thread awhile ago:

I always have a mix of equal parts of Turface, crushed granite (grower/turkey grit), and fir bark on hand because it's my basic bonsai soil mix. For succulents, I add some very coarse sand, and vermiculite, along with a little gypsum or dolomitic lime to round things out. Here's the formula:
3 parts Turface
3 parts crushed granite (farm feed store)
3 parts pine or fir bark (see photo for size)
1 part coarse silica sand (masonry supply company)
1 part vermiculite
Dolomitic lime or gypsum
Micronutrient granules

Let me know what you think. ;o)

Take care.

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by jodik 5 Central IL (My Page) on
    Tue, Mar 18, 08 at 13:14

Actually, Al, I enjoy your rants because they help me to absorb the information! Let me explain... a few years ago, I was a passenger in an auto accident and was knocked unconscious. Head injuries take a long time to heal, and in the interim, I find I have much less memory than I once had. So please, rant away... and by all means, do repeat yourself! It really does help me to take in all the information! :-)

Anyway, I understand now why I shouldn't throw in a layer of coarse material before the soil... and since I bottom water most of my bulbs, not having that layer will most likely help water to wick up into the root area faster, and when I flush the pots, to drain out quicker...

Bottom watering helps keep the moisture at the root level, and keeps it away from the actual bulb... too much moisture around the bulb tends to allow rot to set in fairly fast... and then, every so often, I leach the excess salts and minerals by flushing with clear water from the top of the pot.

So, my conclusion is... screening over the hole in the pot will work much better than a layer of coarse anything. Unless... that layer is thin and consists of very small pieces of charcoal...

By the way... STEM is fabulous! At least, my plants seem to think so! :-)

Thank you!


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Mar 18, 08 at 16:20

Hi, Jodi - You're welcome. ;o) glad to hear all's well with your plants, and especially that you're doing OK after the bump.

Sounds like you've got everything under control. Congrats - I know you work hard at keeping up with all that's associated with attending to all your plants. Take good care.

Glad you like the STEM, too ....

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks for the quick reply Tapla.
Im going to try and make a batch this weekend. There is a garden center that carries a good variety of items in small sizes and bulk. I do have some questions about the ingredients.

1. Does it matter what kind of turface I get or should I look for the MVP since that is what seems to be used most?

2. Is there any pro and con to the different kinds of bark? Would there be any reason to look for one over the other?

3. Am I using the sand mainly for the silica? If so can I use Diatomite instead? It says that it is 90% silicon dioxide and has a slow release of silica. My mom uses it for her orchids so it's readily available to me.

4. Is there something I can substitute the vermiculite with or just not use it at all? You mentioned in another post that it breaks down and compacts quickly and that I can provide the Mg and Ca in other ways.

5. I assume the difference between dolomitic lime and regular lime is that the regular stuff is a powder form and will just go to the bottom of the mixture. I also assume that I am using the lime or gypsum to raise the pH. If so, I am just curious what is making the mixture acidic. I know that peat is acidic and most peat mixes need lime to help bring it to a neutral pH.

6. And lastly, :), I see that you didn't say to use any CRF and just micronutrients. Why wouldn't I need to any CRF. I was also wondering if you have ever heard of ZeoPro? My mom ordered some and according to the literature on the stuff it provides a "complete suite of minor and trace nutrients". I am almost positive that this is in a granular form, but it may be a powder. I should know for sure this week.

Thank you so much for the help and information. I am quite excited to give this a try!! :)

Ross


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Mar 19, 08 at 0:08

1. Does it matter what kind of turface I get or should I look for the MVP since that is what seems to be used most?

Yes - use MVP only. I mentioned that several times upthread, but I often forget to add the 'MVP' later, taking it for granted that you know. Sorry about that. ;o)

2. Is there any pro and con to the different kinds of bark? Would there be any reason to look for one over the other?

I've used southern yellow pine, fir, and hemlock bark - all with good results. The SYP will be easiest to find. As long as it's conifer bark, particle size will be the primary consideration.

3. Am I using the sand mainly for the silica? If so can I use Diatomite instead? It says that it is 90% silicon dioxide and has a slow release of silica. My mom uses it for her orchids so it's readily available to me.

Actually, I use it for it's physical properties. It seems to tighten the soil w/o any compacting, and provides additional surface area to hold water for short periods w/o supporting a PWT. It serves the same purpose as crushed granite, except it's finer. You can do without it if you choose. The diatomite comes in lots of varieties/types (raw, calcined, flux-calcined) so I really couldn't say. I'm guessing though that there would be little difference between that & Turface, except that calcined diatomaceous earth is generally even more porous than Turface & has a higher CEC. Since the silica wasn't being added to the soil for its porosity - if you choose to add the CDE, you'll probably want to reduce the amount of Turface in the mix accordingly.

4. Is there something I can substitute the vermiculite with or just not use it at all? You mentioned in another post that it breaks down and compacts quickly and that I can provide the Mg and Ca in other ways.

You can leave that out too, if you wish. There is nothing carved in stone. The recipe is just a mix that I've been using for a long time, and one I've provided to other succulent growers who really liked it, and the feedback from them has been exceedingly favorable. It's no accident that the vermiculite is about 9% of the total mix. I do use it occasionally in soils, and have found it a very good addition to the recipe I offered. There will be no compaction if you keep the total volume down around 10%.

5. I assume the difference between dolomitic lime and regular lime is that the regular stuff is a powder form and will just go to the bottom of the mixture. I also assume that I am using the lime or gypsum to raise the pH. If so, I am just curious what is making the mixture acidic. I know that peat is acidic and most peat mixes need lime to help bring it to a neutral pH.

The pelletized lime is prilled powder, so it dissolves quickly, too. You should incorporate it into damp soil when you are mixing it. Much of it will be retained in the micropores of the Turface and bark, and some in the minute surface irregularities of the rest of the particulates. In the recipe above, I'd probably choose to add gypsum instead of lime (unless you use a Ca/Mg supplement like Botanicare Cal-Mag Plus when you fertilize). The pH of the above soil will come in around 6.5 or so, so if you wish to stay south of a pH of 7 (neutral) you should use the gypsum, which doesn't affect pH. If you use the gypsum, make sure your plants are getting Mg, because gypsum won't supply it.

6. And lastly, :), I see that you didn't say to use any CRF and just micronutrients. Why wouldn't I need to any CRF. I was also wondering if you have ever heard of ZeoPro? My mom ordered some and according to the literature on the stuff it provides a "complete suite of minor and trace nutrients". I am almost positive that this is in a granular form, but it may be a powder. I should know for sure this week.

I didn't suggest a fertilizer because you said "terrariums", so I thought you would have a favorite. Also, I notice more salt build-up when I use CRFs, and I knew that you wouldn't care for that in an enclosed terrarium. Perhaps I missed something?

There's been lots of hype about ZeoPro & the space program, but really, it's just clinoptilolite (a naturally occurring form of zeolite). It's often used as a soil treatment. Its primary value is as a slow release source of K, but if it was treated with ammonium during manufacture, it can similarly serve as a slow release store of nitrogen. Neither of these benefits seem particularly impossible to do without to me (just add N at will or include a little potash when you make your soils for the extra K kick if you think it's needed. Their website makes some pretty outrageous claims "... has intelligence that actually communicates with your plants ...", reminding me of Superthrive.

More important though than it's chemical claims is its physical characteristics - its particle size. If you think it's the right size for one of the soil components, substitute it or add it if you choose. If it's really porous - sub for Turface - if not so porous, sub for the granite.

Take care. ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks so much Al, for answering all those questions.

I am going to have to make a shopping list of different possibilities and see what's available at the store. But I have more reading to do first.

Right now I have four terrariums. I have only been making them for a year since I saw some at the Philly flower show. I've read and have been told to fertilize very very sparingly so the plants don't outgrow the terrarium. So, to say the least, I have yet to fertilize a single one, and most of my other plants as well.

Here is a link to my terrarium album:
http://public.fotki.com/EPGamer/plants/my-terrariums

I also have pictures of most of my succulents on there as well, which I only fertilized once, and I screwed that up. After I watered all of my succulents a couple of times with Jacks Classic 20-20-20, ALL of my pots started to get covered in white build-up. I originally thought it was mold/fungus because I was watering with dehumidifier water (another long story :). It of course turned out to be a build up of minerals leeching out of the clay pots. I have yet to fertilize them again.

BTW, I buy a special mix for my succulents made at another garden center that looks similar to your mix in the middle of the picture above, just more rocky.

I found your post about the "Fertilizer Program". That will be my reading for tomorrow, because I really need to understand how to fertilize properly, since all I ever use is the 20-20-20 ;)

When I first started growing plants three years ago, I never realized how much there could be to it, but I still love it!

Thanks you again

Ross


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RE: Container Soils Water Movement & Retention IV

I forgot something important. The reason why I asked if I should put CRF in the mix is because the MiracleGro soil has some three month stuff in it. So the plants have food for a little while when I first put them in. I'm sure a couple of them could use some food, like the first one I made almost a year ago, but I am worried that I will hurt the plants more then help.

Ross


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Mar 19, 08 at 21:05

Strong work, Ross. You've done a really nice job. I'm impressed. ;o)

I don't think I'd use the CRF. I think you should try to maintain closer control of your nutrient supplementation than you could if you just add CRF. Please do read the fertilizer thread. Pay particular attn to the thoughts about high P fertilizers like those with a 1:1:1 ratio. Plants use about 6 times more N than P when both are in the adequacy range, so 1:1:1 fertilizers supply about 6 times the P plants use. That translates to lots of extra salt accumulation in your soils. If you are supplying all the other nutrients, you can limit growth by reducing the amount of N you supply.

Lets go back to the ZeoPro you were talking about for a sec. If you included it in your soils, it would serve best as a slow release provider of K, and possibly N if it was so treated. Plants use about 3-1/2 times as much K as P, so if you fertilized sparingly with 0-10-10, you could pretty much control vegetative growth with how much additional N you provide while furnishing approx the correct ratio of both P & K. Are you with me?

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks for the compliments ^^

Im not sure if I am with you or not. I've been reading all night again tho.
So, if I was to not use the ZeoPro, then I would want to go with a 0-10-20 and provide the N as need be? Let's say I want to grow the plants for a few months, then slow them down, I would then use a regular fert with the 3:1:2 and then once I want to slow the plants down, decrease the N considerably? And not worry about the micronutrients right away since I've put the granules in the soil mix? Are there products that add only P and K, and then something else to just add N? I feel like I am back in chemistry class!

I read the fert. thread and I know one thing for certain, I need to find some good literature, there is definitely a lot more then just planting, watering and feeding (which I royally screwed up). I can't tell you how many people have told me to just use a 20-20-20 to be safe :(

I did find some sites on how to diagnose different nutrient deficiencies in plants, so that should be a start in understanding the needs of each nutrient.

Also, how important is it to know the TDS and pH of my tap water? I only use distilled water in my terrariums, but I use tap for everything else. I researched my water departments water analysis but they don't list the TDS. Is it worth having tested? I use a pH test kit for fresh water aquariums on my tap and it shows about 6.8-7.2, but I don't know how reliable these kits are. I just want to be able to take care of my plants as best as I can ^^

Thanks so much
Ross


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RE: Container Soils - Water Movement & Retention IV

Wow! I went looking for information for potting my new dwarf citrus and ended up here. A lot of great info to take in and try to understand.

I was really, truly hoping I'd find some easy, out of the bag product to buy. I'll admit.. I'm a lazy newbie gardener who just wants to grow some fruit in pots and teach my kids about the wonder of gardening... never did I think I'd end up seriously concocting my own home-brew soil. And now I'm so excited about doing it I can't wait to hose out my wheelbarrow and get started. LOL

That said, I want to push back and ask you about 3 things:

1) Your mix is so contrary to what all my local independent nurseries (I've asked at 3 different places) and even to what the folks at Four Winds recommend, I am needing some extra convincing. Maybe it's how I'm "wired" to really understand something well before proceeding.

You've probably addressed this before, but I'm very new to GW and have only posted a couple times at the Citrus Forum, so please bear with me.

The guys at Four Winds, in their own materials, say:
"Use a soil mix that is lightweight and drains well. If the mix is dense or contains peat moss, amend your soil mix with 1/4-1/3 volume of 1" redwood shavings."

They're saying to use one of the commercially available potting mixes... which from your write-up would be a HUGE no-no.

And they recommend adding "redwood shavings" rather than pine. Is there a difference? Is either of these things the "gorilla hair" that I see in new landscaping as a mulch?

And in a separate email with someone at Four WInds, he told me I could also use Cedar chips, because they repel the ants better. And if I'm understanding your info, chips of any size would be bad because they will ultimately decompose and collapse the soil, right?

Also I'm confused about why a company that sells citrus would deliberately encourage their customer base to plant their potted citrus in something that will cause their plants to fail, and fairly soon it seem like judging from the high rate of failure I have seen on the citrus forum.

Yet every nursery specialist that I have talked to tells me to use potting soil---and they all look at me like I have 3 heads when I start talking about home-brewing my own soil/potting mix.

Is it possibly that they expect most people to pot a citrus, spend a year or 2 before it dies, then buy a new one?

2) My second sort of question, concern really... deals with whether the mix you're recommending is "organic" or geared to "green gardening"... so to speak. I completely understand why not to throw a bunch of organic matter into the mix (because it will compact the soil)... but on the flip side of this there have been a lot of materials listed in this post that are new to me. Are they chemicals? Do they leach into the food. Does the Turface MVP stuff have, say, petrochemical residue from the manufacturing process? I'm not just trying to grow lush beautiful plants... I want to be able to eat them and trust that they, themselves, are "organically" grown. Does your mix fit within those sorts of loose paramaters.

I hope I don't sound like a crazy cook... but I'm the first to admit I'm of the granola-crunchy California persuasion. I'm not far from Berkeley here. LOL

3) And finally, you mention that your mix is great for succulents. Do you have a specific mix for potting citruses?

Thank you very much,
Kristi


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  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Mar 20, 08 at 7:15

Hi, Ross & Kristi. I have to go keep the wolf away (work), but I'll answer later. Such a skeptic, Christie. (big grin - playing off your admission) I can't wait to get to your reply. ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

WOWOWOWOWOWOW!!!!!!!!!!!!
Kristi.........I was told the same thing by Four Winds and I have been dealt the same way by my local greenhouse!!!
Never thought to ask the way you did..I am sure Al will have a great anwer as soon as he thinks this one over!!!HUM..lol
Looking forward to your thoughts AL.;:)


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RE: Container Soils - Water Movement & Retention IV

MeyereMike, I have been asking this everywhere, too. I even asked on the citrus forum (half in jest) if Four Winds would just sell the stuff they use in their black pots.

AL... two more questions if you have it in ya...

1) What kind of Pots???? This is my first time growing citrus (or anything other than anuals in small pots). I was surprised on the citrus forum to see so many people growing in plastic pots and many even using the commercial black plastic.

I guess there are pros and cons of both.

Terra cotta = breathes better but is darn heavy.

Plastic = doesn't breathe as well and roots might get hotter in summer, but they are so much easier to move around and easier to work with when planting up, which is a given if I'm lucky enough to have my citrus thrive.

Is your mix particularly suited to plastic since it seems like it drains extraordinarily fast?

And if so, would you add more organic material if you were using terra cotta?

I'm in the SF Bay Area, about an hour inland... and we get about a month of some very scorching summer days and I'm afraid the plastic pots will deteriorate and bake the roots. And I don't particularly like the look of them. So I'm still on the fence about what to use.

2) My second question has to do with growing blueberries in a pot. That'll be the next thing I plant this spring, and my nursery gave me a handout with instructions to use 1/3 pathway bark, 1/3 peat moss, and 1/3 leaf mold plus 2 TBS of Soil Sulfur. What do you think of that mix---for blueberries, that is.

And yes, I am a bit of a skeptic and am eagerly awaiting your repsonse.

Thank you very much for the time and dedication you put into helping all of us here.

-Kristi


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RE: Container Soils - Water Movement & Retention IV

Ooh-ooh-ooooh! (Arm raised in the air like Horshack on Welcome Back Cotter.)

It seems like the more I learn---and the more I start thinking this all through---more questions occur to me.

These questions are both specific to me planting citrus... but I'm guessing that the science behind the soil/aeration is about the same.

1) I am considering potting a standard Satsuma tree (i.e. non-dwarf). I've been told repeatedly that one of the main reasons to only pot up 1 size (only a couple inches bigger than current size) is so not to drown the plant with too much soil.

Since your mix has such incredible drainage, would it stand to reason that I could actually go up maybe two pot sizes, or more? Have you personally tried this? I am mainly asking about the larger satsuma, because I'd like to get it into the largest, stablest terra cotta pot I can now so that I can let it stay there a while. With my dwarf's, I'm resigned to having to start small and pot up slowly... though if you told me this soil would facilitate a larger pot that would be nice, too. I just don't want to be transplanting a standard tree every other year.

2) Speaking of my dwarf's, using your formula, about how quickly would you think they stay in one pot before going up to the next pot size. I vagely recall in this or one of your other posts, you mentioning you're potting up every year? Does this potting mix help make plants grow faster & bigger? (At this point, I'd be happy with just keeping them alive. But a girl can dream, right? LOL)

THANK YOU again! Can't wait to see your responses to my many questions. And I hope it's not a bore to those of you reading who are already advanced using this information. Don't mean to hog the board with MY questions.


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RE: Container Soils - Water Movement & Retention IV

Aaaack... I started reading the OTHER Al/Tapla posts...

and, if I'm reading it all correctly, I've stumbled on something seemed contradictory to me:
A) Needing more frequent watering as a result of improved drainage, and B) incompatability with drip irrigation systems.

1) Needing more frequent watering. This mix, and Al's and other people description of how it works, SOUNDS like it needs daily watering. In one of the 150 +posts, someone named Untitled pushed hard that he couldn't do daily watering.

And seemingly contradictory... I THINK I saw a post that this mix doens't work well with drip irrigation systems, which is probably what I will eventually put these on after I figure out their watering needs.

So Al... if I were someone who couldn't guarantee a daily watering and might want to space that just a little----but still benefit from all the theoretical improvements you're recommending... are there adjustments you can make to the mix to make it hold water better, while still being well draining? I'm hoping you have already experimented with this before, or at least been asked about it.

And, yes, ONE MORE questions...

I have a couple of half-used bags of the potting mix my local nursery recommends for everything (and I've got all my flowering annuals in it now). I'd like to use as much of it as I can because it wasn't cheap.

Would you be able to look at the description below and see if I could mix it with the right things to give it the same or similar draining properties of YOUR mix?

It's called "Gardener's Gold" from Master Nursery:

"Gardeners Gold[tm] Organic Potting Soil - 2 Cubic Feet
A rich, all natural blend of finely screened, composted fir bark fines, worm castings, real topsoil, redwood peat moss, chicken manure, and sand. pH balanced with dolomite and oyster shell limes. Rich in long-lasting plant nutrients. Water saving formula. Provides excellent drainage. Good for all indoor or outdoor container plants."

Like, could I maybe add perlite or turface and give it a go?

Or should I just chuck it into the yard?

THANKS again and again and again.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Mar 20, 08 at 16:24

Ross - You wrote So, if I was to not use the ZeoPro, then I would want to go with a 0-10-20 and provide the N as need be? Let's say I want to grow the plants for a few months, then slow them down, I would then use a regular fert with the 3:1:2 and then once I want to slow the plants down, decrease the N considerably? And not worry about the micronutrients right away since I've put the granules in the soil mix? Are there products that add only P and K, and then something else to just add N?

Your 0-10-20 idea is pretty close. Any fertilizer with a P:K ratio of about 1:2 that is low in N (an example might something like a 5-10-20) will be a good choice to keep growth contained. Some growth is necessary though, to prevent decline. On the flip side, if you want the plant to experience closer to a normal growth pattern, the 3:1:2 ratios should work very well & I would rate them the best o/a choice.

... how important is it to know the TDS and pH of my tap water? ... Is it worth having tested? I use a pH test kit for fresh water aquariums on my tap and it shows about 6.8-7.2, but I don't know how reliable these kits are.

It's just nice to have a good idea, if you're fertilizing containers based on a parts per million basis. I would strongly suggest that you continue to use the dehumidifier water, or deionized (distilled) water for watering your terrariums if you plan on keeping them. It will help immensely in keeping the level of soluble salts in the soil at lower levels. The kits are fairly accurate, btw.

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Mar 20, 08 at 17:00

Kristi - I don't know if I'll get all the way through your posts or not. I have to do a bonsai demonstration for our club in a couple of hours, & I haven't even picked a tree yet. ;o) If I don't make it all the way through, I'll p/u where I left off.

1) Your mix is so contrary to what all my local independent nurseries (I've asked at 3 different places) and even to what the folks at Four Winds recommend, I am needing some extra convincing. Maybe it's how I'm "wired" to really understand something well before proceeding.

Well, I'm not being smart or speaking unkindly when I say that if you need additional convincing, I'm not apt to be twisting your arm very hard. You can trust what I say, or you can read through the 4 threads on this subject to get a feel for the hundreds of people that have taken away from my posts that long term aeration is key in container soils. If that's all you take with you, I'll be very happy & feel like I've accomplished something.

I'll answer several of your questions by saying that it really doesn't matter what the soil is made of, as long as it holds the right amt of air and water & isn't phytotoxic. I choose ingredients for my soils that are the most durable (long-lasting) I can find, and that maximize water-holding ability while providing excellent aeration. I can tell you haven't read the entire post, because these questions are all answered in it.

Both the bark-based soil and the gritty mix I often suggest will have close to 80% total porosity, with about 35% air porosity when the soil is fully saturated. That is the mark of an excellent soil.

As far as the soils being organic - the bark soil has the same ingredients in them as bagged soils, and the gritty mix is just granite, Turface (baked clay) and bark. I consider these soils totally compatible with organic practices.

As I scroll down through your posts, I'm realizing that it might take hours to type out all the answers, most of which are provided upthread. Many of the answers are overshadowed by your other concerns, and I have no feel for what questions are most important. You could help me out immensely if you ask a few of the most important questions & hold on until I answer them. Often, I'll be able to head off lots of other questions in my reply. I guess what I'm saying is "Let's organize our conversation." It will save me lots of effort & help insure that others will be able to follow & gain from it.

Take care.

Al



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RE: Container Soils - Water Movement & Retention IV

Hi Al,
Thanks again, and I do apologize for blitzing you with questions. I see what you mean about your answers (if I had waited for them) may pre-answer some of my follow-up questions. You are always thorough and add so much value to this forum in everything you say.

I assure you I have read this post, twice actually. And I've started onto the other posts you link to. But I admit it's a lot to take in and I'm still trying to absorb them all and apply it to my own specific situation.

I think my questions are simply me trying to validate what I'm learning.

I can certinly wait on your answers so that they can be organized in a way that everyone will benefit. Surely I'm not the only one to wonder about these things.

Thanks! Have a good bonsai demo.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Mar 20, 08 at 23:40

Thanks, Kristi. I root-pruned/repotted 2 trees for the group - a black elderberry (lacy black foliage & looks much like a Japanese maple dissectum) and a pomegranate that came from your state (Roy Nagatoshi's nursery a little south of you). We had fun & the group was really lively & full of questions, but nothing like you. ;o) Lol

Ok - I'm going to answer your most recent post now. If you still have questions, please just re-ask in manageable numbers & I promise I'll answer every question I'm capable of. Deal?

In soils, there will be an inverse relationship between drainage/aeration and irrigation frequency. As intervals between the need to irrigate increase, it must follow that the soil must hold more water. To a large degree, this means that the soil particles must become smaller to hold the extra water, which decreases aeration. I make no claims that the soils I grow in are the most convenient, though I believe they greatly simplify growing in containers. The price you pay for good drainage and aeration is more frequent watering. Only you can decide if it's worth it to you.

There is a price to be paid for the convenience of not having to water for extended intervals and it comes in the form of decreased root vitality. You will have to balance the vitality/convenience equation as you think best. The soils I make for myself and suggest here are designed to retain very little perched water so that root vitality (and thus plant vitality) can be maximized. It is impossible to maximize root vitality in any soil that supports perched water. To be sure, you can grow healthy/happy plants in some soils that support perched water, but you cannot achieve maximum vitality. Saturated soil kills roots and it kills them quickly.

There is nothing that says these soils WILL need watering daily. That is still a function of plant mass, container size, and a whole host of other cultural effects. If you can't water daily, and your plants need water daily, unless you can solve the problem, it does little good to consider growing in a soil that cannot keep your plants hydrated, but there are some things you can do to boost the water-holding ability of your soils and still maintain a high degree of aeration.

You refer to theoretical improvements, but there really isn't much theory involved in what I'm setting down here. The physical science in what I'm saying is pretty absolute, and my many years of practical experience along with the affirmation from many other forum participants also serves to move what I'm saying from the theoretical to the proven column. The real test comes in how you apply/adapt anything you learn here to your particular application - or how you don't apply it, as you choose; but, at least you should have a better understanding of the cause/effect of the relationship between drainage/aeration and a soils ability to hold water and how it affects your plantings.

It's really difficult for me to gauge what I would do with your leftover bags of soil. My intuition tells me that you could probably treat it almost like the peat component of the 5:1:1 mix at the top of the thread. Why don't you try mixing 5 parts of bark, 2 parts of your soil, and 1 part of perlite and tell me what you think?

I have a dear friend I visit with frequently who lives in Fremont (near you, I believe) and grows all her many citrus & other trees in a variation of the bark/Turface/granite mix. I believe she uses 2/3 Turface and 1/3 composted redwood bark, She is much happier after having made the switch in comparison to before, growing in prepared potting soil. I KNOW she often goes many days between waterings, so it's not going to be too difficult to build a soil to suit you and your trees - if you wish.

BTW - you can always arrange for a phone conversation where I can answer all your questions as they arise (hopefully) ;o) and go into more detail. Let me know.

Take care.

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by jodik 5 Central IL (My Page) on
    Thu, Mar 20, 08 at 23:53

I'm very interested in what Al will have to say about the bark issue, and more to the point, what he thinks about using cedar.

As a veteran dog breeder, I keep any and all cedar products, including bedding, mulch or anything else made from cedar as far away from my property as possible. There is a naturally occurring chemical in cedar that can damage the kidneys and other internal organs of animals, the same chemical that repels insects I would think, and I take no risks when it comes to the health of my dogs. I couldn't tell you the name of the chemical found in cedar, but I do know that cedar is not a good thing to have around if you own animals. We use aspen bedding, which is much healthier and a lot less dusty than other bedding, including pine.

If you don't have animals or young children, it's not so much an issue... but if you do, be aware that cedar is damaging to internal organs! (I would guess that's why hamsters and gerbils don't live very long when bedded with cedar...)


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RE: Container Soils - Water Movement & Retention IV

Hi Al,
So I suppose it's good that you didn't answer all my questions because it sent me on a seek and find mission. I've pored over the old listings, had a bunch of "a-ha" moments, and found the answers to a lot of my questions and concerns.

But I'm hoping you can answer me these two...

Terra Cotta vs. Plastic:
In one post I think you answered you have a slight preference for terra cotta, and that it offers more margin of error for overwatering. But do you adjust the mix based on which kind of pot you're using, or is it irrelevant.

Drip Irrigation
Saw some sort of debate about whether your mix is compatible with drip irrigation systems. Will I be able to put all these pots with your soil on drip?

It's surprising that my local nurseries (even the "good" ones) say to use commercially available potting mixes when they so clearly fail. I guess it's just a prevalent paradigm... but I'm not going to debate it with them. I've had all the convincing I need here on your posts and I'm almost ready to mix.

Thanks again!


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Longevity of the different mixes?

Hi again,
Can you please say something about the relative longevity of your two mixes (i.e. Peat/Bark/Perlite vs. Turface/Bark/Granite).

Can you put a "life span" (so to speak) on the mixes?

You have said that commercial mixes might only last a single growing season before the roots rot.

Whereas your Peat/Wood/Perlite will last longer, but "how much longer?" she asks.

And then you have said that your Turface/Bark/Granite mix can last "almost indefinitely." Does that really mean never having to refresh the soil and repot?

thanks for your ongoing lessons. ;-)

-kristi


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Apr 3, 08 at 17:04

Hi, Jodi. I must have missed your post somehow - I'm sorry. :o(

"Cedar" covers lots of territory. I can think of at least 6 different genera of trees besides Cedrus, claiming the common name 'cedar'. I know that most are rich in bio-compounds that are a product of metabolism and repel insects, but I have never used any bark from a tree with even the common name "cedar". Sorry, but I can't comment on toxicity issues w/o going & researching it. Can I invite you to look into it & come back & share? ;o)

In one post I think you answered you have a slight preference for terra cotta, and that it offers more margin of error for over-watering. But do you adjust the mix based on which kind of pot you're using, or is it irrelevant.

The benefit of using a container with gas-permeable sides is to allow additional gas exchange in the soil, and to increase evaporation so that air returns to the soil more quickly. A side benefit comes in the form of cooler root temps due to the evaporative effect. Though you may wish to tweak a soil to help you get through from watering to watering, you shouldn't increase water retention so much that the benefits are lost & it ends up being much the same as growing in a plastic or glazed container.

Read more here and more here, too

... saw some sort of debate about whether your mix is compatible with drip irrigation systems. Will I be able to put all these pots with your soil on drip?

I suppose that's kind of hard to answer, because I don't know what you intend to do with the recipe, or which you'll use. I think they should be fine if delivery is via a mist emitter or if delivery is slow so water gets a chance to disperse by diffusion, rather than run through the container because the rate was too high.

It's surprising that my local nurseries (even the "good" ones) say to use commercially available potting mixes when they so clearly fail. I guess it's just a prevalent paradigm... but I'm not going to debate it with them.

Well, I can tell you that not every person working at nurseries and greenhouses is well informed. Some are, some are not. Often, the help is seasonal, unless you get to the key people. A parallel: You wouldn't believe it if I told of the conversation I had with a "lawn maintenance expert" this AM, who was bidding on the lawn care (not the mowing) at my business. He was the owner of the (his) business, but his lack of expertise was really astounding.

Can you please say something about the relative longevity of your two mixes (i.e. Peat/Bark/Perlite vs. Turface/Bark/Granite). Can you put a "life span" (so to speak) on the mixes?

You can tell, I'm really a believer & a stickler about aeration. I don't reuse my soils, but I have grown lots of plant material in the 5:1:1 mix for two, and sometimes 3 years when I get lazy. It hasn't been a problem when the plant/soil/container are all together for the duration, because the root mass actually becomes part of the soil structure and helps provide aeration, even as the soil itself is decomposing. The problem comes when you remove the plant material and try to reuse a collapsing soil. Eg: How much perlite does it take to make pudding drain well? ;o)

So, I would MAYBE reuse the 5:1:1 mix once. The gritty mix will last for far longer than 'most any plant/soil combination should remain in the same container (because it's getting root bound).

You have said that commercial mixes might only last a single growing season before the roots rot.

Not quite. I don't usually speak in absolutes about that sort of thing. I think I probably said that peat-based soils will see considerable collapse before the end of a single growing season. If you were lucky enough that roots were somehow able to colonize the entire container, the effect would likely be fairly minimal. If the soil held too much water, or your irrigation habits were less than ideal - erring on the heavy-handed side, roots may not have been able to grow into the lower parts of the container, in which case the loss in plant vitality could be considerable, even to the point of killing the plant as a result of rotted roots.

... your Peat/Wood/Perlite will last longer, but "how much longer?" she asks.

You've already seen that most peat mixes are in danger of collapsing within the period of a single growth cycle. Since bark is stable for about 4 times as long as peat, and that increases as the particle size increases, it's probably fair to say that the bark soil will outlast the peat soil several times over. The real question can't be answered because your idea about when a soil is no longer serviceable is probably much different than mine.

And then you have said that your Turface/Bark/Granite mix can last "almost indefinitely." Does that really mean never having to refresh the soil and repot?

No. Unlike some plants (like many houseplants) that will require repotting simply because the peat-based soil they're in has collapsed, the gritty mix will remain serviceable for several years. With this soil, the need to repot and root-prune will come as a result of the degree to which the plant is root-bound, rather than because of soil collapse.

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks Al.

OK, so I think my strategy (since I'm essentially lazy LOL) will be to use the gritty Turface/wood chip mix and pot in terra cotta pots that are about 4" diameter larger than what they are now. My hope is that I can maximize the amount of time before having to repot. ;-)

What I don't understand yet is whether the Turface Gritty Mix has a greater requirement for fertilizing than the Peat/Wood/Perlite mix.

So the fertilizer post is my next destination, after the kids go to sleep. I expect more questions once I get there. ;-)

Sheesh, I wonder if anyone has ever explained how all those orangeries in France have lasted these hundreds of years. Maybe there was an Al Tapla back then?


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RE: Container Soils - Water Movement & Retention IV

Ok, where to begin.

First off, Talpa, do you ever take a vacation away from home? I'm installing drip irrigation around the yard because I lose at least a plant a year to neglect when I'm away over the summer. A fast draining, non-retaining mix would only increase the mulch pile upon my return.

Ok, maybe not the biggest concern...

I like what i've read, enough that I will try to pot up at least a couple of my containers using a mix more like what you are describing. At the very least I will be adding wicks to a couple of my larger pots in an effort to increase the usable soil for those plants.

Have you ever heard of a plant which doesn't like the mix you use?

~Chills


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Apr 3, 08 at 21:23

I vacation with some trepidation at having someone in to water things. I always return to find that a few plants missed their drinks & have suffered for it.

I never claimed the soils I use can fix everything. ;o) You can't have it both ways, expecting to have looonng intermissions between irrigations and maximize vitality too. (no snotty tone here - smiling as I exhibit my keen grasp of whatever seems obvious) ;o) The soils I make for myself are designed to have very little or no perched water and to maximize water-holding ability within durable particulates when possible, while offering some adjustment in the volume of water held by varying only an ingredient or two.

Have you ever heard of a plant which doesn't like the mix you use?

I'm not really selling anything like "My Mix". If you read through the thread, you can see that I genuinely WANT to help people learn about soils and their effect on plant physiology. I have many years of experience growing in these mixes and I've never seen a plant that didn't grow very well in them when I tend to business. 'Lazy and inattention' are my biggest enemies when it comes to any plant mortalities. I can honestly say though, that they are very few.

If any plant is known to do poorly in a well-aerated mix, you should avoid those I use, but if you cannot show where a plant DOES do poorly in that type of mix, any problems with vitality should almost certainly be attributed to grower error or general inexperience. Except for having to water and fertilize more frequently, soils like I suggest take a great degree of the worry and guesswork out of container culture. These soils really are a very good point from which to start or restart growing endeavors, but as always, the ball remains in the reader's court. ;o)

Still waiting on the answer to the Turface question you posed in the Fig forum. I e-mailed 2 bonsai buddies from the DET area & I'm sure one will reply yet tonight. I'll let you know.

Cheers, Chills.

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks Al. (for locating the Turface, though I think I found a closer source)

I am sold on the wick idea (I'll try it in a couple containers this spring).

I bring my figs inside over the winter. When doing so one wants the plant to dry without overdrying. I've got the watering down pretty well now, but I worry that wicking out all the water will make giving the plants sufficient water for dormancy difficult (I guess I'm wondering if the plants are using that level of trapped water) Is my concern incorrect on some level?

~Chills


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Apr 4, 08 at 22:21

You're welcome. I sent a follow up in your mail, too.

Inside - as in the garage or outbuilding - right?

Yes, they use water from the container via capillary action and diffusion. Throw a few handfuls of snow on them from time to time. I "watered" my trees over-wintering in the garage 3 times during the winter.

Take care.

Al


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RE: Container Soils - Water Movement & Retention IV

Hi Al,

I've noticed interesting thing about the fabric bag by Root Control is that the whole bag acts as wick so your mix seemed to dry out pretty fast compared to ordinary plastic container!

I have a couple with heavy mix growing in the root control bag and they seem to do fine but it's hard to water though. The water just flows off the top to the side where the water comes out. I thought it was interesting thing with the fabric bag.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Apr 6, 08 at 10:42

You're using a cultural technique that invites drying of the soil periphery and you're surprised that it's drying quickly? ;o)

In seriousness now - many organic soil components become hydrophobic when moisture levels drop below certain levels. For conifer bark and peat, that level is approximately 30%. 'Coco-wet' or 'Agri-2' wetting agents would go a long way toward alleviating the problem if it's something you cant/don't want to live with.

Al


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RE: Container Soils - Water Movement & Retention IV

Hi Al, I have read the entire 4 threads with much interest. Unfortunately, I only really got to the discussion of lime vs. gypsum AFTER I made up a batch of basic mix containing dolomite lime.

Your older recommendation was to use sulfur to lower ph for acid-lovers, but it seems your newer advice is to avoid the lime and use gypsum when you want the ph on the acid side of 7.

So I have three questions:

1. Am I correct in assuming your updated advice is to use the gypsum and supplemental Mg for acid lovers, rather than the lime/sulfur combo? If so, is it a huge difference or just a minor one?

2. What effect does powdered eggshells have on the ph? I have always used that instead of lime for my worm bin, and it does seem to raise the ph. But I wondered -- because your succulent mix called for "gypsum or eggshells."

3. Any specific mix ratios you might recommend for strawberries and/or blueberries would be appreciated. I'm thinking you'd probably recommend your "gritty mix" for the blueberries?

Thanks very much!

Jenn aka wormgirl


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Apr 7, 08 at 11:20

Elemental S will help lower pH in containers somewhat over the long term, but I usually don't recommend it for that purpose because it's so slow.

1) Media pH is important, but less so than soil solution pH, but I still try to keep media pH south of 6.5. Since the gritty mix I use has a pH around 6.2-6.5 before amending, I feel that the gypsum is a better choice as a source of Ca because it doesn't affect soil pH to any significant degree, unlike dolomite. In the 5:1:1 soil, which has a considerably lower pH before liming (5-5.5), I usually prefer to add the dolomite, but if I was growing blueberries, I'd use the gypsum.

2) You must be going WAY back. ;o) I don't remember suggesting eggshells, but I'm sure I might have, depending on the context of the conversation. Eggshells do raise pH, but not significantly because they break down very slowly. The main ingredient in eggshells is calcium carbonate (chalk, limestone, etc.) The shell itself is almost all (about 95%) CaCO3. The remaining 5% includes proteins and some calcium phosphate and magnesium carbonate. So, if you choose to use eggshells, you'll need to supplement the Mg, or make sure it's included somehow.

3) Yes, I would grow them in the gritty mix. 2:1:1, 2:1:2, and 1:1:1 fertilizers are good choices for blueberries. You should prolly avoid using nitrate forms of nitrogen and chloride forms of potassium. The nitrate and chloride can be toxic to blueberries.

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks so much, Al. I have a couple follow-up questions:

1. You mention media pH and soil solution pH. If you have explained the difference upthread, I apologize for missing it. I'm supposing it has to do with testing pH dry vs. wet. In practical application, what do I need to know about this?

2. When you use eggshells, do you merely crush them or actually powder them in the blender? When used as a fine powder, I'm fairly sure it has a pretty dramatic effect on my worm bin's pH (that's what I'm using it for, after all!) If one were to merely hand-crush the eggshells, though, I could see that having little effect on the pH (as a matter of fact, I found this ineffective in the worm bin). Then again, it would probably release a lot less Ca into the soil at one time. So the question is: how would you crush the eggshells, and about how much would you use?

3. Gypsum is not carried at my local Home Depot, Lowes, or my favorite garden center. Before I look more, I thought I'd ask about the best place to find it. Would they carry it at the feed store?

Thanks again, Al. I think I remember your advice from years ago when I used to frequent this forum. I only wish I'd known about your mixes back then!

Jenn

PS: I DID find "Soil Pep," composted fir and pine bark, at the local Home Depot - for those of you seeking pine fines.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Mon, Apr 7, 08 at 17:41

Hi, Wormgirl. I remember you from when you were here a long time ago. ;o)

1) There is a lot to understand about pH in containers and how your irrigation water hardness and alkalinity, as well as its buffering capacity and the buffering capacity of the media affect the o/a picture, but I'll try to give an overview w/o getting into that area, most of which isn't too important to us anyway.

Media pH is a measure of the o/a concentration of H ions in dry media. Media pH impacts pH of the media solution which, like nutrients, would be subject to rapid change if not for the buffering effect (CEC) of solid components in the media. So the importance of media pH to plants is not only its effect on ease/difficulty of nutrient uptake but more importantly, the availability of nutrients for diffusion/dissolution into the media solution.

In short, media pH determines which nutrients might be available at a favorable media solution pH, and the media solution pH determines a plants ability to take them up in that solution. Since we are usually providing nutrients in a fertilizer solution that is designed to deliver nutrients at favorable pH levels, the media pH becomes less important than the media solution pH.

2) Just as particulate size affects the delivery rate of nutrients like sulfur and dolomite, it would affects that of eggshells. Why not leave them lightly crushed and use them as part of the soil structure. You could probably use as many as you wish. If you powder them, I suppose I would use them at a rate of 1 tbsp/gallon of soil & double that if they are crushed to a fineness similar to kosher salt.

3) I'm surprised you can't find gypsum. Feed stores will probably carry it - hardwares that sell fertilizer, too. I just saw it at an Acco Hdwe, if you have those near you. Do you have OSH's there? They would have it. As a last resort, Espoma makes it & bags it in either 5 or 10 lbs (I forget), but it's as much as 50 lbs at the other places & there's no difference - their lime is like that, too.

Hey! The 'Soil Pep' sounds like a really good find!

. . . promise you'll take care? ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

Thanks, Al, for that explanation of media pH vs. soil solution pH. Believe it or not, I actually truly understand the sentence about the concentration of H ions in dry material - we were just learning about that last night in physiology class! Sometimes info comes to you just at the right time... anyway, the way you explained it is very helpful.

I did find gypsum at Lowe's, they just didn't bother putting it on their website. Do you use the same proportion as for dolomite lime?

I am frustrated trying to source ingredients for the gritty mix. First, bark. The size difference between "fine" and "medium" bark seems enormous. The finest medium bark I found is screened through 3/4" screen. I found "mini nuggets," but the type of wood was unspecified.

Secondly, I bought Turface at my local John Deere Landscaping, and that seemed easy -- until I realized I'd come home with what must be an older product called Turface "All Sport." They do not list this product on their website, so I don't know how it compares to the MVP in particle size. I called the manufacturer to ask, but was only able to leave a message. Hopefully they either call me back, or someone here will be familiar with the older product. I'm pretty sure I can scare up some MVP here in town, but I wonder if I can use what I have.

Thirdly, everyone around here carries chicken and pidgeon grit, but not turkey. All grits I've seen so far also have either oyster shells and/or additives. I have looked at crushed rock (too big) and sand (too small). I found pumice, but I was actually hoping for something heavier, and available in bags (it only comes in bulk). I have found Gardener Bloome "Horticultural Sand" which seems PERFECT, except it only comes in tiny, houseplant-sized bags. I have access to all the free pea gravel I want, but that's a bit big. Maybe I should go investigate the pool sand, but it sounds expensive.

I expect my blueberries to be delivered at the end of this week and hope to pot them Friday. I will probably find good resources for these materials eventually, but at the moment, I'm trying to figure out what my best gritty mix options are. Tempted to try 1/2 bark and 1/2 turface, since they love it both acid and moist. I am also wondering about a little peat for the acidity. If anyone has opinions on my best options, I'd love your input!

Jenn


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Tue, Apr 8, 08 at 20:51

Do you use the same amount of gypsum as dolomitic (garden) lime?

Yes - use a tbsp/gallon or 1/3 - 1/2 cup per cu ft.

I am frustrated trying to source ingredients for the gritty mix. First, bark. The size difference between "fine" and "medium" bark seems enormous. The finest medium bark I found is screened through 3/4" screen. I found "mini nuggets," but the type of wood was unspecified.

The same bark goes into the gritty mix as goes into the 5:1:1 soil. What happened to the 'Soil Pep' you found? You don't think you can use it?

You should also be able to find fir bark there. Shasta Forest Products is in northern CA and they're a really big producer of bark. That's what I use in my gritty mix - screened fir bark. I buy it in 4 cu ft bags and last time I paid about $100 for 6 bags.

If you let me know what major city you're in/near, I'll see if I can get in touch with bonsai friends/contacts near you & see what I can chase down. Those wheels sometimes turn slower than I'd like, so a little patience might be required.

I've never used or seen Allsport before, so I can't really advise you. Can you describe the particle size? If you have access to a product called "Play Ball", you may wish to consider that instead of Turface. It's calcined diatomaceous earth and is actually superior to Turface in several ways.

Silica sand in the 1/16" size wouldn't be too hard to find, or too expensive, as a replacement for granite. Anywhere that sells swimming pool supplies, or a masonry supply store (not big box) will have coarse silica. I paid $8 for the last bag.

If you do the bark/Turface Allsport mix, I would use 2 Turface:1 bark. If you find the mix stays too wet, wick it until the planting matures & water retention becomes desirable, rather than a hindrance.

Take care, Jenn.

Al



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RE: Container Soils - Water Movement & Retention IV

Hi Al - thanks, I emailed you regarding bonsai supply. I guess I thought I wanted *larger* chunks for the gritty mix. Perhaps I have the wrong idea there? Some of the fir bark you show in the pictures seems slightly larger. I'd love to just use my "Soil Pep," since I already have plenty.

I just broke open the Turface "All Sport" and my hope is that it's the old name for MVP, or an older, similar product. It's particles range from about 1/16th" to 1/8th", with a few larger. It does not look like the "more uniform, smaller" particles in the product meant for slides. If I'm lucky the mfg. will call me back to let me know for sure, but it seems like the right stuff. I only got one bag - I will look for the actual MVP next time.

I feel much encouraged already, Al. I will either make it to a masonry supply or swimming pool supply before planting time, or I'll just go 2/3rds Turface. Thanks for helping me formulate my plan! I WILL take care, and you do too, Al.

Jenn

PS: I think this thread is pretty near 150 replies - just a heads-up.


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RE: Container Soils - Water Movement & Retention IV

Just got a call from the manufacturer. Turface All-Sport is the exact same product as Turface MVP - it's just packaged as All-Sport by John Deere Landscaping.

I think it's the only type John Deere carries, because they didn't ask what type I wanted. I paid just under $10 a 50lb bag. I put the store locator link below.

Jenn

Here is a link that might be useful: John Deere Landscaping Store Locator


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RE: Container Soils - Water Movement & Retention IV

That's good to know, Jenn. A lot of people (myself included) initially struggled trying to find a source for Turface MVP. Knowing that John Deer carries it under a little different name should help many people out.


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RE: Container Soils - Water Movement & Retention IV

John Deer near me would have to special order Turface, but they have something called Pro Choice Soil Conditioner (in red). Al, ever seen/used this stuff before?

I picked up Espoma Soil Conditioner, but the Pro Choice stuff is about the same price for twice as much.

~Chills


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RE: Container Soils - Water Movement & Retention IV

Does the stuff from John Deer look the same as the Espoma Soil Conditioner (not counting color)?

What you want looks like this (not counting color)

Photobucket

It also doesn't hurt to soak a cup or so worth in water overnight to ensure it doesn't turn to mushy clay. If it is roughly the particle size in the pic and doesn't get mushy when saturated, it's good to go.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Apr 9, 08 at 19:36

Hey guys - could I have the 150th post so I can leave a link to the next thread after I get it up and running? I'd really appreciate it. Please don't answer. ;o)

Al


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Apr 9, 08 at 20:13

I didn't mean to cut you guys off. I had hoped I might catch the end of the thread at a more convenient point. Can I invite you to continue the discussion on the new thread?

Al

Here is a link that might be useful: Follow me to the new thread, please.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Apr 10, 08 at 7:27

See immediately above for a continuation of this thread.

Al


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RE: Container Soils - Water Movement & Retention IV

Hi all, not sure I'd classify myself as a "grower" but I do dabble with my blue spruce. I have maybe a thousand I've grown from seed, ranging in size from 3" to 12" now, and still in 5" plugs.

This fall I will transplant about 250 of the largest to 1 gal. pots and see how it goes (and move to 2 gal. next year, once I see how things develop.

I've been researching soil-less container soils. I can buy Pro-Mix or the Sunshine Mix #4 but am concerned that the pH will be a bit high. I understand that in order for a blue spruce to be "blue" (at least for the 50% that have the ability to turn blue from the regular kaibab variety - although I have many "Majestica" that claim 90% will turn blue, and have some (claimed to be) "Misty Blue" which apparently were selected from the best of the Majestica orchard, but are no longer harvested) the pH should be about 5.5 or even less. I think both of the above pre-mixes have pH's greater than this.

One mix I saw called for about 20% perlite, 20% vermiculite, 60% sphagnum peat moss, and 1/2 cup each of bone meal, blood meal, and dolomitic lime per 8 gallons of mix. I suspect that if I were to use this mix for blue spruce, I might eliminate vermiculite and reduce the lime to maybe 2 tablespoons? It looks from this thread that using primarily pine bark fines may be adviseable? I suppose I could also substitute turface for perlite although not sure I could find same. I don't know if I'd need any other additives like CRF? I'm hoping to keep costs down. It seems to me that I can mix my own soil for about 1/3rd less cost than pre-mix, unless I'm missing something? I have hundreds++ more blue spruce coming down the pipeline, so cost is important.

Sorry for being so new at this. It was enjoyable planting the seeds (all outdoors, which was a challenge) but now a few years later I want to keep going with this, so am on to the potting stage. Any advise is helpful.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Jun 8, 08 at 16:29

Personally, I wouldn't consider the "20% perlite, 20% vermiculite, 60% sphagnum peat moss, and 1/2 cup each of bone meal, blood meal, and dolomitic lime per 8 gallons of mix" you mentioned. Even if you DO decide to use it, I can tell you that the .5 cup of blood meal suggested is enough to (by itself) supply maximum nitrification to more than 3.4 cu ft of soil (25.5 gallons). The bone meal breaks down so slowly in containers that it is very ineffectual as a Ca/P source as well.

You should be able to use the 5:1:1 mix and add gypsum instead of lime to keep pH down to <5 as a starting point. Use MG 30-10-10 as your fertilizer & add in 5 lbs potash per yard of soil (1/2 cup/cu ft). That should keep pH low enough. The gypsum supplies S and Ca missing from the MG, so the only thing left for you to supply in the way of nutrients is Mg. You can do that by including 1/4 tsp Epsom salts/gallon of fertilizer solution each time you fertilize.

Alternate (and a good choice if you want to spend the money): Instead of the extra potash in the soil, you could use Dyna-Gro's 'ProTeKt' 0-0-3, which also provides silicon, which is particularly beneficial in container culture.

I was contacted by a grower in PA last year about a soil/fertilizer program for Black Hills spruce, and the above is what I suggested. He was very happy with the results.

Take care.

Al


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RE: Container Soils - Water Movement & Retention IV

Al:

Thanks for all of the above. I'll see if I can find pine bark fines. So far our horticultural wholesaler said they didn't have it. Someone told me just to use wood chips, i.e. in our municipality they retain the wood chips from the trees taken out, for use as compost (I've asked them if they have Black Walnut mixed in, which I think is toxic), as it's free. In any case, I'll look for the pine bark fines, and my question is - what does the potash do, is it to add nitrogen or potassium? And will I need the micronutrient powder after all of this, or does the Miracle Gro and/or other additives indicated cover for both SRF and micronutrients? Thanks, I need to get it right on this batch of blue spruce, and as mentioned want to keep costs down, as I have a over a thousand outgrowing their plugs.


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Jun 11, 08 at 9:21

It would help those responding to your posts if you included where you live in Canada so we can have at least some idea of your weather patterns. In this case, it might offer a hint about what types of bark might be available in your neighborhood. I'm not sure if Can. has zones like the USDA zones, but if you know your equivalent USDA zone, it would be helpful stuff, too. BTW - what street is Canada on? ;o)

Wood chips are not what you need for containers. If they were fine enough to be useful from the physical perspective, they will break down too quickly and tie up nitrogen. When using a wood product, stick with conifer bark only. I have used pine, hemlock, and fir, and found them roughly equal in performance.

Potash supplies potassium (the 'K' portion of NPK). Since your trees will use about 3/5 as much K as N, the 3:1:1 ratio fertilizer will be somewhat deficient in it's ability to meet the plant's K needs. Other than that, the fertilizer is a very good choice. It doesn't supply Ca and Mg, but you won't need a micronutrient supplement if you follow the outline I offered - they're covered, along with the sulfur that is missing from the MG 30-10-10.

There is also no need for a CRF if you're diligent about fertilizing.

Al


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RE: Container Soils - Water Movement & Retention IV

Al, this is very helpful.

My "street" in Canada is Ontario, actually a small town near Sarnia (about 30 minutes east of Port Huron, Michigan). I think we're zone 6(a) but I understand that many plants/trees rated for zone 6 tend to "expire" fairly quickly. We don't have alot of conifers in our area, naturally growing - we tend to be more the hardwoods. I'm still striking out on locating bark chips (got another email back this a.m.) but I think there may be a mill north of us (if it still exists) so I'm going to check there.

Hoping we can keep up our dialogue, it's quite interesting and very helpful.


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RE: Container Soils - Water Movement & Retention IV

A big thanks for this article. Pearched Water Table and conditions that give rise to it were something I knew nothing about and it sure explains the problems I've been facing. Thank you so much!


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RE: Container Soils - Water Movement & Retention IV

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Jun 13, 08 at 11:06

JLG - the dialog depends on you. ;o) I'm around almost every day & try to answer any questions that are addressed to me whenever I can. That you find the info & dialog interesting and helpful is pretty much my reason for being here, so I'm very pleased that you say so. Thank you.

Oscar - you're so very welcome. I always hope that people reading the OP at least keep the info in the back of their minds - even if they don't embrace the concept in practical application. It, for those folks, can still be a helpful diagnostic aid if ever things go awry. Your post stands as testimony to that fact. Thank you.

Al


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RE: Container Soils - Water Movement & Retention IV

Question for Al:
It was hard for me to find park bark fines but I found some an hour north of me. Now I have just a few bags left and am getting the jitters of "what do I do when they're gone".
Here in Florida we have shredded eucalyptus mulch which I use (as mulch) because it breaks down much slower than other mulches.

Do you think it could replace pine bark fines in the mix?
I guess I could try an experiment and plant the same plant in the two mixes to compare.

Just wanted to ask your opinion. I have heard that cypress mulch inhibits growth so I won't use that.

TIA

Denise


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