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Container Soils - Water Movement & Retention XII

Posted by tapla z5b-6a MI (My Page) on
Wed, Nov 3, 10 at 20:15

I first posted this thread back in March of '05. Eleven times previous, it has reached the maximum number of posts GW allows to a single thread, which is much more attention than I ever imagined it would garner. I have reposted it, in no small part because it has been great fun, and a wonderful catalyst in the forging of new friendships and in increasing my list of acquaintances with similar growing interests. The forum and email exchanges that stem so often from the subject are, in themselves, enough to make me hope the subject continues to pique interest, and the exchanges provide helpful information. Most of the motivation for posting this thread another time comes from the participants' reinforcement of the idea that some of the information provided in good-spirited collective exchange will make/has made some degree of difference in the quality of many readers' growing experience.

I'll provide links to some of the more recent of the previous eleven threads and nearly 1,800 posts at the end of what I have written - in case you have interest in reviewing them. Thank you for taking the time to examine this topic - I hope that any/all who read it take at least something interesting and helpful from it. I know it's long; my hope is that you find it worth the read.

Container Soils - Water Movement and Retention
A Discussion About Soils

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. Soils are the foundation that all container plantings are built on, and aeration is the very 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/compost/coir. Durability and stability of soil components so they contribute to the retention of soil structure for extended periods is also extremely important. Pine and some other types of conifer bark fit the bill nicely, but I'll talk more about various components later.

What I will write also hits pretty hard against the futility in using a drainage layer of coarse materials as an attempt to improve drainage. It just doesn't work. All it does is reduce the total volume of soil available for root colonization. A wick can be employed to remove water from the saturated layer of soil at the container bottom, but a drainage layer is not effective. A wick can be made to work 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 basic mix recipes later, in case any would like to try the soil. It will follow the Water Movement information.

Consider this if you will:
Soil fills only a few needs in container culture. Among them are: Anchorage - A place for roots to extend, securing the plant and preventing it from toppling. Nutrient Retention - It must retain enough nutrients in available form to sustain plant systems. Gas Exchange - It must be sufficiently porous to allow air to move through the root system and by-product gasses to escape. Water - It must retain water enough in liquid and/or vapor form to sustain plants between waterings. Most plants can 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; in other words, water's 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, and 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 said to be 'perched'. The smaller the size of the particles in a soil, the greater the height of the PWT. This water can be tightly held in heavy (comprised of small particles) soils and 'perch' (think of a bird on a perch) just above the container bottom where it will not drain; or, it can perch in a layer of heavy soil on top of a coarse drainage layer, where it will not drain.

Imagine that we have five cylinders of varying heights, shapes, and diameters, each with drain holes, and we fill them all with the same soil mix, then saturate the soil. The PWT will be exactly the same height in each container. This saturated area of the container is where roots initially 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 dependent on soil particle size 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. From this, we could make a good case that taller containers are easier to grow in.

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. An illustrative question: How much perlite do we need to add to pudding to make it drain well?

We have seen that adding a coarse drainage layer at the container bottom does not improve drainage. It does though, reduce the volume of soil required to fill a container, making the container lighter. When we employ a drainage layer 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 using the same soil 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 on soil particles 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 employ 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 in the container to a few inches below the bottom of the pot, or allow it to contact soil below the container where the earth acts as a giant wick and will absorb all or most of the perched water in the container, in most cases. Eliminating the PWT has much the same effect as providing your plants much more soil to grow in, as well as allowing more, much needed air in the root zone.

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.

Bark fines of fir, hemlock or pine, 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 nature's preservative. Suberin, more scarce as a presence in sapwood products and hardwood bark, dramatically slows the decomposition of conifer bark-based soils. It contains highly varied hydrocarbon chains and the microorganisms that turn peat to soup have great difficulty cleaving these chains.

To confirm the existence of the PWT and how effective a wick is at removing 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 and allow the water to drain. When drainage has stopped, 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. The water that drains is water that occupied the PWT. A greatly simplified explanation of what occurs is: The wick or toothpick "fools" the water into thinking the pot is deeper than it is, 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 in the thread.

I always remain cognizant of these physical principles whenever I build a soil. I have not used a commercially prepared soil in many years, preferring to build a soil or amend one of my 2 basic mixes to suit individual plantings. I keep many ingredients at the ready for building soils, but the basic building process usually starts with conifer bark and perlite. Sphagnum peat plays a secondary role in my container soils because it breaks down too quickly to suit me, and when it does, it impedes drainage and reduces aeration. Size matters. Partially composted conifer bark fines (pine is easiest to find and least expensive) works best in the following recipes, followed by uncomposted bark in the <3/8" range.

Note that there is no sand or compost in the soils I use. Sand, as most of you think of it, can improve drainage in some cases, but it 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 fine and unstable for me to consider using in soils. The small amount of micro-nutrients it supplies can easily be delivered by one or more of a number of chemical or organic sources that do not detract from drainage/aeration.

My Basic Soils ....
5 parts pine bark fines (partially composted fines are best)
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime (or gypsum in some cases)
controlled release fertilizer (if preferred)
micro-nutrient powder, other source of micro-nutrients, or fertilizer with all nutrients - including minors

Big batch:
2-3 cu ft pine bark fines
5 gallons peat
5 gallons perlite
2 cups dolomitic (garden) lime (or gypsum in some cases)
2 cups CRF (if preferred)
1/2 cup micro-nutrient powder (or other source of the minors - provided in some fertilizers)

Small batch:
3 gallons pine bark
1/2 gallon peat
1/2 gallon perlite
4 tbsp lime (or gypsum in some cases)
1/4 cup CRF (if preferred)
micro-nutrient powder (or other source of the minors)

I have seen advice that some highly organic (practically speaking - almost all container soils 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) 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, fine stone, coarse sand (see above - usually no smaller than BB size in containers, please), Haydite, lava rock (pumice), Turface, calcined DE, and others.

For long term (especially woody) plantings and houseplants, I use a superb soil that is extremely durable and structurally sound. The basic mix is equal parts of pine bark, Turface, and crushed granite.

1 part uncomposted screened pine or fir bark (1/8-1/4")
1 part screened Turface
1 part crushed Gran-I-Grit (grower size) or #2 cherrystone
1 Tbsp gypsum per gallon of soil
CRF (if desired)
Source of micro-nutrients or use a fertilizer that contains all essentials

I use 1/8 -1/4 tsp Epsom salts per gallon of fertilizer solution when I fertilize (check your fertilizer - if it is soluble, it is probable it does not contain Ca or Mg.

If there is interest, you'll find some of the more recent continuations of the thread at the links below:
Post XI
Post X
Post IX
Post VIII
Post VII

If you feel you were benefited by having read this offering, you might also find this thread about Fertilizing Containerized Plants helpful, as well.

As always - best luck.

Al


Follow-Up Postings:

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RE: Container Soils - Water Movement & Retention XII

  • Posted by jodik 5 Central IL (My Page) on
    Thu, Nov 4, 10 at 15:21

I was wrong! It was already at 11... this makes it number 12! My bad!

Here's wishing many more thread rollovers... and many new friends and gardeners made! :-)


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RE: Container Soils - Water Movement & Retention XII

  • Posted by filix z5 maine (My Page) on
    Fri, Nov 5, 10 at 16:59

There is no thread in any forum no matter what the subject, where I have learned so much. Not just about container gardening. But gardening in general. Because they are all linked. Many thanks Al. Filix.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Nov 6, 10 at 14:33

Thanks, guys! Photobucket That was a very nice way to kick off a fresh start. ;o)


Al


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RE: Container Soils - Water Movement & Retention XII

To Al (or others with experience in repotting):

I have 3 new mango trees that I want to containerize. I'm in the process of collecting the ingredients for "Al's Gritty Mix" and I have studied about the proper pruning techniques and pest control. What I need now is help with the actual repotting procedure. When planting in the ground the consensus seems to be to cut away the bottom and place the nursery pot in the hole and carefully cut the sides to keep the root ball intact. But how do I do the planting in a container?
1. Do I want to remove all the nursery peat-type dirt from the roots and plant the bare roots in the new Gritty Mix?
2. Will there be danger of root shock?
3. Do I do any pruning of the roots if the tree was root bound in the nursery pot?
4. Any other tips on proper handling of mango roots during repotting?

Curt


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Nov 10, 10 at 16:51

Hi, Curt. It's probably a little off topic to begin a repotting discussion on this thread, but I took the liberty of copy/pasting your comments/questions to another thread dedicated to maintaining trees in containers, and answering there. I hope that's OK by you.

You will find the reply here. Scroll down to the bottom of the thread, or to my post dated 11/10/10.

Take care.

Al


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RE: Container Soils - Water Movement & Retention XII

What is the best mixture for container Herb Gardening? Yes I am a Noob so what is the best ratio of what materials?

Thanks

Todd


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Nov 19, 10 at 8:56

I grow a wide variety of herbs in the gritty mix. They love the drainage and porosity.

From above: For long term (especially woody) plantings and houseplants, I use a superb soil that is extremely durable and structurally sound. The basic mix is equal parts of pine bark, Turface, and crushed granite.

1 part uncomposted screened pine or fir bark (1/8-1/4")
1 part screened Turface
1 part crushed Gran-I-Grit (grower size) or #2 cherrystone
1 Tbsp gypsum per gallon of soil
CRF (if desired)
Source of micro-nutrients or use a fertilizer that contains all essentials

I use 1/8 -1/4 tsp Epsom salts per gallon of fertilizer solution when I fertilize (check your fertilizer - if it is soluble, it is probable it does not contain Ca or Mg.

Al


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RE: Container Soils - Water Movement & Retention XII

Here's to thread like this! :-))))))))))))))))))))))))))

From my plants and myslef, my family and friends, a HUGE THAN YOU Al....I wish I had met you years ago when I was digging deep into my pockets to replace the plants I lost without this information, while filling the pockets of the plant and soil mix industries..

I also appreciate learning how particle size makes a huge impact on the "PWT" within my containers, something I had never heard of before, nor did some of my local nusery owners or workers for that matter..Being in control of it and learning how to manipulate it, I find it has been a God send.

Using the "wick" method until I could change my plants into this far superior mix has saved a many plant of mine.

I even stopped putting sand,compost,backyard dirt,pebbles,stones,crushed crab shell,styrofoam, worm castings, coir, charcoal, and many other things into my containers when I read my first thread like this.

I also save TONS of money on not buying into the idea, nor the expensive products, that my mixes need to be injected with microbes and bacteria to make food available to my plants.

Lately, there seems to be no room in my conatiners for any pest's or uneeded PWT's but just good ole fashioned healthy root systems..

With deep appreciation Al!

Mike


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RE: CContainer Soils - Water Movement & Retention XII

Please excuse my spelling..I previewed it 6xxxxxxx and didn't notice any errors until I posted of course..
I think I need a coffee before I share my thoughts this early in the am...

Sorry

Mike


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RE: Container Soils - Water Movement & Retention XII

More Coffee Mike. ;)

I have catnip and chives growing very well in the 5-1-1 and several other herbs to be planted this weekend.

JoJo


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RE: Container Soils - Water Movement & Retention XII

I use a bagged mix with some perlite. As long as you have good light indoors, they should grow well.

Basil, Parsley, Sage, peppers
Basil, Parsley, Sage,

Jane


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Fri, Nov 19, 10 at 15:10

Todd - most of the people that participate on this thread are interested in improving on the results and minimizing the problems so often encountered when using peat-based commercially prepared soils; others are satisfied with the results they get from these soils and have no interest in changing anything, which is absolutely fine. I've been offered a good opportunity to explain something about the (lack of) efficacy in trying to amend heavy bagged soils by adding some perlite, so I'll expound a little, basing what I offer on science and my own practical experience.

Perlite doesn't change the drainage characteristics of a soil or the height of the PWT. To visualize this, think of how well a pot full of BBs would drain (perlite), then think of how poorly a pot full of pudding would drain (bagged soil). Even mixing the pudding and BBs together 1:1 in a third pot yields a mix that retains the drainage characteristics and PWT height of the pudding. It's only after the BBs become the largest fraction of the mix (60-75%) that drainage & PWT height begins to improve.

You cannot add coarse material to fine material and improve drainage & the ht of the PWT. Use the same example as above & replace the pudding with play sand or peat moss - same results. The benefit in adding perlite to heavy soils doesn't come from the fact that they drain better. The fine peat or pudding particles simply 'fill in' around the perlite, so drainage & the ht of the PWT remains the same. All perlite does in heavy soils is occupy space that would otherwise be full of water. Perlite simply reduces the amount of water a soil is capable of holding because it is not internally porous. IOW - all it does is take up space.

If you want to profit from a soil that offers superior drainage and aeration, you need to build it into the soil from the start, by ensuring that the soil is primarily comprised of particles much larger than those in peat/compost/coir, which is why the recipes I suggest as starting points all direct readers to START with the foremost fraction of the soil being large particles, to ensure excellent aeration. From there, if you choose, you can add an appropriate volume of finer particles to increase water retention. You do not have that option with a soil that is already extremely water-retentive right out of the bag.

Al


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RE: Container Soils - Water Movement & Retention XII

  • Posted by jodik 5 Central IL (My Page) on
    Fri, Nov 19, 10 at 18:33

I concur with Al... optimum success can easily be had by building a good soil for my container plants, and that's exactly what I've done. I'm extremely satisfied with the results using a rendition of Al's Gritty Mix. I'd never go back to using the retail version of soil in bags. It might be convenient, but it's still muck.


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RE: Container Soils - Water Movement & Retention XII

Here's my catnip. There's also Dusty Miller and 2 pansies in this.
A few leaves sunburned when I first set it out, and they're slowly getting better. But other than that, it's doing great and grows like crazy.

I prune it constantly to give to my cat. :)

Photobucket

Also, here's a link you may be interested in seeing if you haven't already. Some wonderful examples of the different things that grow in the mixes.

JoJo

Here is a link that might be useful: What better way to say


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RE: Container Soils - Water Movement & Retention XII

Hi Al,

I'm trying to post all these questions to the appropriate thread. I'm using the wick as you have described for my gritty mix containers as an extra layer of protection. My question was can I use the wetness/dryness of the wick as a gauge to when I need to water next?

If the wick is dry I think I can assume that the gritty mix is also dry. However, if the wick is wet does that necessarily mean that the gritty mix is wet? My garden is a north facing shade garden so it takes longer to dry out then most.

Thanks,

Kernul1 (Bill)


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Sat, Dec 4, 10 at 15:55

Yes, the wick can serve as a reliable 'tell'. Check it for dryness as close to the soil as possible and water when it's dry to the touch.

Al


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RE: Container Soils - Water Movement & Retention XII

Al, you helped me tremendously this summer when I chose to change to the 5:1:1 mix for my fall planted tomatoes. They LOVED it and I had excellent production on my fall tomatoes versus the others I'd planted in potting mix. So, I actually had a side-by-side comparison analysis. What a difference! And, believe me, our weather (extreme heat and humidity this summer) was not especially conducive to growing anything at all. So, many thanks.

I discovered the issue of PWT (inadvertently, and I didn't have a clue that I was seeing anything that I should take note of, when wintersowing my seeds in my soda bottle containers. I used regular potting mix, of a better quality, and filled the containers with about 6-7" of the PS. Then, I wet the soil. Even though I had put lots of drainage holes in the bottom of the soda bottles, the water just completely refused to drain, and it was sloshing back and forth in this container. Me thinks, how odd! I thought the drainage holes were clogged with dirt, so I poked a wooden skewer thru each hole from the bottom and was absolutely floored at how much water drained out of it. Every time thereafter that I watered the containers I would lift them up so I could see whether water was draining properly or not (most often it was not), and so I repeated the procedure. Now, once the roots filled the container, I didn't seem to have the problem. After reading your posts this last summer, it clicked, duh!

The problem for a lot of is that we cannot see inside our containers to know what is happening with PWT. So, growing my seeds in clear soda bottles allowed me to actually observe what was happening. Still, I didn't really make the connection until I read your analysis of what was happening inside the container that I couldn't see.

Would you recommend this 5:1:1 mix or something else for winter sowing in lieu of potting mix? There may be a lot of interest in the answer because the method of winter sowing includes using a deeper layer of potting mix than most "seed" pots allow. A lot of perennial seeds germinate and put down extensive roots during the winter, so PWTs and aeration, particle size and everything that is so important to root growth, goes unobserved.

Once again, I commend you for sharing all of this information with everyone at GW!

Susan


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Sun, Dec 5, 10 at 15:25

I would definitely recommend using something like the 5:1:1 mix for winter sowing of seeds for short term plantings, and the gritty mix if you're planting anything perennial that you intend to keep in the same container for more than 1 growth cycle.

My winter sowing has been pretty much limited to tree seeds that need to stratify. My normal MO is to sow on top of the gritty mix, then cover with fines screened from the Turface, but you could sow on top of the 5:1:1 mix and cover with peat if you like. On top of my 'planting', I usually put down a layer of window screen to discourage birds, rodents, and to act as a brake so the rain doesn't wash seeds out. Of course, I'd skip this step if I was keeping the seeds in the garage, but many of the more hardy seeds just get left on a bench on the north/back side of my garage & left to their own devices.

Gee, the forums have been good to me lately - lots of nice comments/compliments. I do thank you for that, Susan. Much appreciated! You can probably tell I enjoy helping where/when I can. ;-)

Al


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RE: Container Soils - Water Movement & Retention XII

Sorry if this question has been asked in the over 1000 previous messages in these threads... I have to admit that I have not read them all. I did make an attempt to search for an answer, though. :)

I was wondering if the soil mixes formulated by Tapla in the first post can be watered from the bottom- i.e. can I simply place a 3-5 gallon pot with this mix in a shallow tray, allowing the soil to saturate via capillary action alone. Does capillary action allow water to spread throughout the pot (but with less saturation) like in heavier soil mixes, or would one have to water from the top in order to achieve good even watering?

I think these lighter mixes would work very well with chili peppers... has anyone tried that before?
Thanks for the advice...


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RE: Container Soils - Water Movement & Retention XII

Al, FYI - I use soda bottles for winter sowing. I cut in half and for the top half, I cut about a 1-2" slit vertically, so I can fold it over to fit in the bottom part of the bottle. This keeps the mice and birds and other critters out, and provides a mini-greenhouse effect for my seeds that need stratification outside. Just toss the lid of the bottle; don't need it.

For seeds that dislike the transplanting process, I use toilet paper tubes or cut up paper towel tubes, fill with soil, put them in the bottle (I can fit up to 4 in a bottle), and then I can transplant the tube, seedling and all.

Susan


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 8, 10 at 10:26

PS - You CAN water from the bottom if you wish, but there is no advantage in soils that support little or no perched water. I would suggest that an0y advantage there might be would be offset by the tendency for soluble salts to accumulate in plantings bottom watered, ie unless you take periodic steps to flush the soil.

It's also possible that not all of the soil would be sufficiently moistened to allow water/nutrient uptake from the entire soil mass.

*****************************

Useful tips, Susan - thanks!

Al


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RE: Container Soils - Water Movement & Retention XII

Plantslayer,
I have grown chiles extensively, in-ground and in containers.
I start my seeds in a gritty mix, then I move them to a 5-1-1 as seedlings.
Outdoors, they either go into the ground or into larger containers of 5-1-1.
In November, I dig them up (or re-pot) and over-winter them in a mix that
closely resembles the Gritty Mix. I fertilize lightly, every couple weeks.

I'll link to my 2010 Pepper Growing Thread for pics of the entire process.

Josh

Here is a link that might be useful: Greenman's Peppers 2010 (pics)


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RE: Container Soils - Water Movement & Retention XII

Can the bark fines be homemade? There are a lot of trees nearby with that type of bark. Or does it need to be put through an industrial wood chipper?


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 15, 10 at 9:13

I suppose, if you have access to pine or fir bark, have a way of separating it from the sapwood, and can mill it to an appropriate size, there would be nothing wrong with home-grown. ;o) I think Al (Calistoga) makes his own.

Al


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RE: Container Soils - Water Movement & Retention XII

On the other hand, how much would all of this cost? I am a simple, amateur organic container gardener starting out a small vegetable garden. Is the cost significantly higher than your typical organic potting soil bag?

I noticed that all of the pots have the PWT that you mentioned (the soil is completely saturated, and it rains every 3 days here. there is no drying out in between and I don't water myself) and when I poke my finger up the drain hole it does start to leak and I can feel it is quite soggy. Would the simple wick solution work for me adequately (I imagine it as a tampon for your pot lol) and where would I go about finding a wick? Can I make one myself?
Thanks a lot and happy holidays!


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 15, 10 at 13:44

How much would all 'what' cost? I don't understand the question?

How well the wick works depends in part on how water-retentive the soil is. You can use a variety of things as a drainage wick. Shoe laces, ties from onion or citrus bags, strips of rayon chamois material or rayon mop heads .... It seems to help if you moisten the wick with a weak solution of dish soap and water before you employ it.

Al


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RE: Container Soils - Water Movement & Retention XII

How much would all of the ingredients to make the soil mix cost?


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Wed, Dec 15, 10 at 20:06

How much soil do you want to make, and which soil?

For the 5:1:1 mix - a 2 cu ft bag of pine bark is about $4, a 4 cu ft bag of perlite is around $20, and a 3 cu ft bale of sphagnum peat moss is about $10. A 50 lb bag of lime is around $7. Using 2 cu ft of pine bark and adding the other ingredients, you'll end up with about 3 cu ft of soil, but you'll have enough peat and perlite to make at least another 15 cu ft of soil if you add the bark.

For the gritty mix - same price on the pine bark, but you'll lose some of it to screening. A bag of Turface MVP will be around $12, and a bag of Gran-I-Grit should be about $7.

Al


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RE: Container Soils - Water Movement & Retention XII

  • Posted by jodik 5 Central IL (My Page) on
    Wed, Dec 22, 10 at 8:00

I just have to say, Josh... great pepper thread! I sneaked over using your link... nice spread! :-)


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Reusing 5:1:1 mix?

Hi Al,

Well i've had amazing success with both the 5:1:1 mix and the gritty 1:1:1 mix.

After cutting down all my tomato plants last week I now have alot of used 5:1:1 mix. Can I screen it and reuse it?

I can restart with a fresh batch of 5:1:1 for this coming spring, but thats going to be a lot of used soil.

What do you do with your used mixes?


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RE: Container Soils - Water Movement & Retention XII

Thanks, Jodi! ;)
Al's mixes have made pepper growing a pure joy.
One of my friends did his entire garden in variations of the 5-1-1 in containers.
He had great luck, as well. His only issue was over-watering and under-watering.
Also, he wasn't following a consistent fertilizer regimen.

Scubastan, howdy! Most of us just add these used mixes to our gardens or garden-beds.
I have seen Al recommend that the old 5-1-1 can be used for the 1 part of peat that
would normally be added to new 5-1-1.


Josh


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RE: Container Soils - Water Movement & Retention XII

Nothing to add other than MERRY CHRISTMAS!!! ;o)

Al


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RE: Container Soils - Water Movement & Retention XII

You too Al!!!!!!! And to you all!


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RE: Container Soils - Water Movement & Retention XII

Hi Al,

I'm making slow but steady progress converting my containers to the gritty mix. The few I have transferred so far seem to love the new media! I'll try to post some pictures later on. Thanks again for all your help answering the many questions I seem to have.

I had a question about gritty mix and raised beds. About half my garden is containers and the other half is raised beds. I suffer from poor drainage in the raised beds as it is north facing and at the lower part of the house.

What are your thoughts on using gritty mix in raised beds? From previous posts of yours I know that the earth acts as a giant wick but for areas with poor drainage would gritty mix help?

Does using fresh gritty mix vs used gritty mix make a difference? For the latter, I've seen you make reference that you recycle "old" gritty mix in your beds. I thought though that the reason the drainage qualities of the gritty mix worked was that all the particles had to be relatively the same size. In a used gritty mix, where the bark had broken down wouldn't it just fill in the gaps of the granite/turface?

Lastly, assuming you did use gritty mix, new or used, in raised beds could you also use foilage pro for fertilizer? I think I recall reading that liquid fertilizers cause salt buildup which you can accomodate for in contianers by flushing it out but does this work the same in raised beds?

Thanks again for all your help!

Best,

Bill


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Dec 30, 10 at 13:55

Hi, Bill - I'm always glad to hear details about how someone is faring when they're using one of the soils discussed here. Actually, I'm always glad to hear details about how someone is faring .... whether they're using one of the soils discussed here or not. ;o) I just like to talk about growing and see what I can do to help others squeeze a little more satisfaction from their efforts. If it works, I'm tickled.

Let's start with why the drainage in the RBs is poor. Is it because they're over clay or bedrock, or because they're in an area where water naturally pools. Also, is there any sort of grade you might be able to take advantage of to direct water away from the growing area?

The gritty mix isn't going to help your drainage issues in RBs unless water has someplace to go TO. If you fill a puddle with the gritty mix, you have a puddle with gritty mix in it.

I use a soil that was originally something like
5 pine bark
5 Michigan peat
5 play sand
5 Turface
in my RBs. I might have added some composted manure and/or some sphagnum peat, but I don't remember. What it looks like now though
Photobucket
is something most RB growers would drool over.

I have been adding any of my used gritty mix to it, along with compost and mulching with 2-3" of pine bark every other year. The soil is REALLY alive and productive. I use the RBs mostly for growing on material that will later be used as bonsai, but ALL the plants I put in it do exceptionally well - better even than those in my gardens & regular beds - and I have excellent soil there as well.

I think that you would almost never want anything as coarse as the gritty mix in a RB - even if the raised bed is on hard clay or bedrock. The physics of water movement in RBs is the same as it is in garden soils, and much different in containers. You actually want a heavier soil in RBs for the added water retention because about the only worry you have that would even be similar to a PWT is the bathtub effect, which is when you have inadvertently created a depression under the RB that traps water. More on that after you answer the questions above.

I don't use FP on the raised beds because of expense. I had to use a high N fertilizer for the first year until the composting process was well underway ..... I think I used lawn fertilizer (27-3-3), but after that, I use a little Milorganite (5-2-0) and a little sprinkle of potash each spring and whenever I see a little yellowing of the deciduous tree leaves; so I end up applying the Milorganite twice each year.

No need to worry about salt build-up from soluble fertilizers unless you live in a very dry area and fertigate very often.

That cover it? ;o)

Happy New Year, Bill. Thanks for the kind words.

Al


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RE: Container Soils - Water Movement & Retention XII

Hi Al,

Thanks for the detailed and thoughtful response! Per your question on the poor drainage; I believe it is a combination of multiple items:

- The garden is in a very low site in the city in between multiple buildings. Essentially it has tall (6'+) retainaing walls on 3 sides. I'm guessing water from these areas also drains into it.
- The garden sits on clay and I believe bedrock is beneath that. .

I don't get pooling of water per se but the soil does take a long time to dry out. I think it is compounded by the fact that the garden is north facing and for about half the year gets no direct sun light (although it does get a lot of reflected light from the surrounding buildings).

It might be easier just to show you some pictures:

Photobucket

Photobucket

Photobucket

I have about 12" of soil now above the clay that I have been slowly adding (combination of fir bark, potting soil, perlite). I'm thinking of just amending in the gritty mix when I start to cycle through it.

Here is a pic of my most gritty mix transplant. Man it is a lot of work between the sourcing, sifting and transplanting but it is very gratifying when it is all done. My potting soils were basically muck and I'm so glad my plants can breathe now in the free draining, well aerated soil mix!

Photobucket

Thanks,

Bill


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RE: Container Soils - Water Movement & Retention XII

i have been trying to test different soil mixes to calculate aeration porosity. i have been unsuccessful at getting accurate results because of the stage where you are supposed to add enough water to just saturate the pot of mix while it has its drainage holes sealed. i find it impossible to assess when there is just enough water, which is essential to the calculations. i also find some mixes expand when watered, and a few contract. nowhere does any formula i've seen acknowledge this, much less factor it in to the calculations.
i appreciate that tapla's 5-1-1 is very highly regarded, but i would prefer to use pro mix bx or fafard #2, and add perlite to increase porosity. i am growing indoors, under lights, in cell packs and 20 row trays, so i need a relatively fine mix.
i have been happy with my seed sowing mixes for 15 years for usual cell packs; but i am starting to use the 20 row trays for sowing alpine seeds, and they are shallow, so the perched water table is a big problem.
i was excited to read about wicks to lower the perched water table, but a casual attempt at that didnt help. i intend to try again, this time suspending the wicks vertically underneath; my first try the wick sloped away and ended lower than the pot, but was lying along a sloped tray, rather than hanging free.
i would at least like to get my attempts at soil porosity calculations to work. i was a chemistry major, as was my husband, but this experiment confounds us.


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RE: Container Soils - Water Movement & Retention XII

Rather than type out the steps, I'll refer you to the link below. If you have any questions after reading the procedure, just ask.

The wicks need to 'fool' the perched water into 'thinking' the container or cell packs are deeper than they really are, so the perched water travels down the wick, 'looking' for what it 'thinks' is the bottom of the container and gets pushed off the wick by the water coming down from above.

Somewhere, I explained how this is SORT of how a SWC works, but in reverse. It's late here, so if you need more help or want to continue the conversation, there's always tomorrow, ;o)

I hope the link is what you need.

Al

Here is a link that might be useful: What you're looking for?


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RE: Container Soils - Water Movement & Retention XII

thank you for the link, and fast reply.
i think the photo of saturated soil was especially helpful.
from that photo, i would say there is actually standing water showing between the particles of soil, just barely short of having standing water submerging the mix. in fact, the soil at the bottom edge of that pot looks under water to me.
i was wondering if there was some transmission of knowledge that occurs in class that wasnt making it into printed instructions.
this really is an instance of a picture is worth a thousand words.
as i mentioned, my wick attempt was rather improvised, as i am just starting seed sowing season.
is there a preferred material for wicks, ie cotton over acrylic? round ply yarn/twine over flat fabric strips? i am assuming i should use as sizable of a wick as will fit through the small drainage holes or slots in my propagating tray inserts.
thanks again.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5a-6b mid-MI (My Page) on
    Wed, Jan 19, 11 at 9:06

"I was wondering if there was some transmission of knowledge that occurs in class that wasn't making it into printed instructions." ???

My favorite wick is the woven nylon closures that (used to?) come on onion and citrus bags, but usually, I use 100% rayon mop strands. Here is a pot I've prepared for a bonsai tree that had just been bare-rooted & root pruned. The 'tail; of the strand hangs below the pot 2-3". My grow benches are the perforated polypro material you see so often in retail outlets that sell plants, so the tail hangs nicely through the holes in the material.

You can use almost any material that absorbs water as a wick for drainage, but when wick watering, it's best to use a material that is very absorbent.

Photobucket

Al


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RE: Container Soils - Water Movement & Retention XII

Hi Al,

I was hoping you could expand on watering frequency for the gritty mix. I've gone back and re-read some of the threads but I'm still a little confused.

In some instances it seems that the benefit of the gritty mix is that you can't over water it and every time you do water the roots get a fresh infusion of oxygen. However, in other instances it seems that you only want to water when the wick is dry.

What is the best approach here? I.e. if I have the time/resources to water every day should I? Or should I only water when the wick is dry. The garden I am working on is north facing with usually 60 degree heat year round (bay area) so it takes longer then usual for the mix to dry out.

Also, I'm using some tall containers (2-3 feet) with relatively small plants whose roots only occupy about the top 4 inches. Does the gritty mix dry out faster from the top to the bottom? I.e. could I run into a situation where the wick is wet at the bottom of a tall container but the top 4 inches of the gritty mix is dry and in need of watering?

Thanks in advance as always for all the helpful information!


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Thu, Jan 20, 11 at 21:34

Because the top of the gritty mix FEELS dry to you, doesn't mean the plant finds it dry. The soil will feel dry when the bark and Turface still have approximately a 40% moisture content, but the plant will still be able to gain moisture from these particles until the moisture becomes too tightly held at about 25-30%, which gives you a nice 'cush' after the top of the soil feels dry.

You CAN over-water a properly made gritty mix if you work at it, but you have to work at it. The gritty mix is designed so the particles are large enough that the soil holds very little or NO perched water. Let's say that the soil you made holds a little bit of perched water at container capacity. Container capacity is the state of water retention after the soil was 100% saturated and has just stopped draining. If you allow the gritty mix to dry down a little before you water, what happens is this: The granite holds water on it's surface. The Turface absorbs water immediately and becomes saturated. The bark is usually either mildly hydrophobic, or even if not, it doesn't absorb water quickly. So - you water - the granite is coated and the Turface is saturated, but the bark is only partially saturated. Any water that would normally remain in the container as perched water very quickly diffuses into the bark, so you have a moist soil with 75%+ air porosity right after the container is watered. THAT is what makes the gritty mix such a productive soil and why it's so good for roots. You cannot have a healthy plant unless the roots are happy - period.

Yes, the roots do get a fresh infusion of O2 every time you water, but with the high degree of porosity, that factor isn't so large a + as it is in heavier soils with poor gas exchange. Since the entire soil mass of a properly made gritty mix is highly aerobic, there is little in the way of excess COI2, methane,m and sulfurous gasses that impede root health/function in heavier soils.

I'm fond of the story about a bonsai workshop I attended, lead by a Japanese master (Ben Oki). One of the participants asked a question, pertinent to this discussion - "How often should I water my (Shimpaku) juniper, Mr. Oki?" His (Mr. Oki's) expression never changed at all as he answered in accented English, "Wait until plant become completely dry - then water day before." To this day, I'm not sure if he was serious or it was his brand of humor, but the advice is sound for almost all plant material.

The gritty mix holds much more water than you would expect. I often leave a volunteer weed in some of my bonsai pots - especially the junipers & pines that like it dry. I usually don't water those plants until the weed wilts, and it usually surprises me to see how long that takes.

Don't water the gritty mix, or any other mix for that matter, prompted by the desire for additional gas exchange. A favorable moisture level is much more important, and the gas exchange issue isn't all that important in the gritty mix. I mainly mention it because it happens to be a + in soils that need watering more frequently.

You'll learn to judge quickly, and though it's parroted that you should never water on a schedule, you'll find a comfortable schedule you won't need to deviate from much with the gritty mix. I have about 100 plants in the basement & they're all on a schedule. I water about 1/4-1/3 every other day, and the rest every 3rd day, though I do have a very few small plants that require a daily drink.

Small plants in tall containers need some special attention until their roots gain some depth. You need to be sure there is moisture in the root zone, so these plantings need more frequent watering until established. Use a wick until the roots are established if you wish. Once the roots grow deep, the roots near the trunk become anchor/conducting roots anyway, so it's not that important if the top of the soil dries out because these roots play no (or very little) part in gathering water.nutrients - only in moving them up & down via cambium/xylem.

Al


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RE: Container Soils - Water Movement & Retention XII

  • Posted by jodik 5 Central IL (My Page) on
    Fri, Jan 21, 11 at 11:10

I will admit... watering the gritty mixes does take some getting used to! But there's no doubt in my mind that it's an exercise in healthier growing! My plants couldn't be happier!

I still have a few bulbs sitting in poor soil... and I'm stunned at how long it takes the soil to dry out. No wonder the roots look so poor, and so many are dead and rotted when I unearth the bulbs to re-pot! Not only can't they breathe without aeration, but they're drowning in all that excess moisture, not to mention all those accumulated salts!

I'm trying to hold on until spring... so I can re-pot every plant not already enjoying the benefits of a more aerated, grittier medium. And in the meantime, I'm learning well how to interpret the watering needs of my "gritty mix garden"!



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RE: Container Soils - Water Movement & Retention XII

One of the main reasons the gritty mix and the 5:1:1 mix work so well is because they retain no (or very little) perched water. The finest roots of plants begin to die within hours, so heavy soils that retain perched water, even when you try to amend them with perlite or pine bark, kill roots if they retain perched water for a significant time.

The plants you still have in poor soil are prime examples of how this works. You water and a portion of the water perches in the container. After a few hours, some of the finest, and most important roots begin to die. The longer the soil remains soggy at the bottom, the greater the number of dead roots, and the larger the diameter of the roots that die.

You wait for the water to be used by the plant and/or evaporate so air returns to the formerly anaerobic portions of the soil. The added aeration stimulates the regeneration of the lost roots & the plant thinks all is well & starts to grow again. But wait! Here you come again because it's time to water, and the process of root death and regeneration starts all over again.

This DOES happen to some degree in the 5:1:1 mix because it can retain some perched water, but it occurs at no where near the level it does in heavier, water-retentive soils, so the cyclic death and regeneration of roots is MUCH reduced as a factor, and the energy that plants MUST put into root generation when grown in heavy soils can be channelled toward growth, blooms, fruit when the plants enjoy soils with superior drainage/aeration.

The gritty mix, when properly made is so healthy because of it's tremendous aeration and durability + the fact that it shouldn't hold ANY perched water.

The price that's paid to adopt these soils lies in the fact that you have to go through the effort to find the ingredients and mix them. The gritty mix, to be made properly, requires that you screen some of the ingredients. Both soils, because of the superior drainage/aeration, require that you water more frequently, and the gritty mix when fully saturated is about 25% heavier than the bagged mixes you're trying to get away from.

I'm a results-oriented guy, and I adhere to what's proven to work best. ..... not an ideologue and dogma be damned! I also don't care about the little extra effort I need to go through to make, in most cases, a very profound difference in the quality of my plants.

Thanks, Jodi. I hope my offering further above was of use to you, Kernul! ;o)

Al


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Correction

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Jan 21, 11 at 16:27

The first statement in the post above is missing a critical qualifier. It should have read: "One of the main reasons the gritty mix and the 5:1:1 mix work so well is because they retain no (or very little) perched water. The finest roots of plants attempting to grow in anaerobic (airless/saturated) conditions begin to die within hours, so heavy soils that retain perched water, even when you try to amend them with perlite or pine bark, kill roots if they retain perched water for a significant time.

Sorry if that seemed confusing.

Al


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RE: Container Soils - Water Movement & Retention XII

Might I add to this Al?

What I also love about the gritty mix in my case is that even though it may take getting use to, in the watering aspect, the chances of me over watering, even if the mix has not dried after I think it has, which is usually in most cases is slim to nothing!

I have found that a majority of my plants like to be evenly moist and not dry out to a wilt, unless they are arid plants able to handle this, which peat or heavy bagged mixes did not allow me to do until it's was too late in many cases.
In fact, most plant directions on many I buy always seem to say " keep evenly moist"...
By the time all the PW would finally dry out, the remaining peat around that PW or rootball would get to hard or pull away from the container and then be inpossible to re-wet. My friend at Home Depot finds this happening all the time. They loose most their plants to over watering or the mix not absorbing water when left to dry to long. Not evenly moist for sure.

My plants were either staying too wet or getting to dry which one would assume, if I am correct, can inhibit proper feeder root growth.
That fine line where roots are perfectly happy through out the mix as a whole without being damaged was virtualy impossble for me.

For me there was never an evenly moist moment and the moisture meters would always give me a false reading.
In the gritty mix there always is that evenly moistness the roots to my plants need and love.

Then there was always a too dry moment for my arid plants and others, which wouldn't allow me to re-water correctly, unless I soaked the pot under water.
I find that the gritty mix fits the bill so that the fine roots are never starving for water or drowning it it. I can easily re-wet it in forced drought circumstances.

Finding that fine line in bagged mixes, or mixes with very fine particles while waiting for that perch water table to diasappear was the hardest thing for me and many others to control or deal with.

I must admit too, I am still finding myself second guessing when to water, but that is where my dowels come in and the forgivness of the gritty mix if I decide not to use them.

At least if I water when I think my mix is dry without my dowels, and it's not, which is usually the case, I am still not over watering my plants.
I also find that moisture, the kind that plants thrive in is available a lot longer than ones thinks, especially containers where the roots have grown into the gritty mix and fill a pot.

Again my gritty mix stays evenly moist, never wet with perched water, the worst enemy of fine roots, especially with my plants, and never too dry unless I forget to water or deliberately let it go to that point.

It has also been noted that even the plants I have that love to go bone dry, respond very well to the griity mix too. A double blessing. This mix is not at all a problem to re-wet.

The best water movement and retention mix I could ever use!

Great job Jodi and thanks Al!!! I love this thread

Mike


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RE: Container Soils - Water Movement & Retention XII

  • Posted by jodik 5 Central IL (My Page) on
    Fri, Jan 21, 11 at 17:21

I understood what you meant, Al. :-)

That extra effort, if that's what you want to call it, is actually valuable to me... I am working more closely with my plants by needing to water more often, which gives me the opportunity to more closely observe and notice what's happening... like growth, budding... and I can more efficiently nip any issues in the bud... like insects, for example. So, I think of it as a win/win situation!



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RE: Container Soils - Water Movement & Retention XII

What you just shared is something I often express when I say there is a MUCH wider margin for grower error in the areas of watering and fertilizing than there is in heavier soils. If you're willing to water a little more frequently, they are MUCH easier media to produce plants in, that are willing to grow as near to their genetic potential as other limiting factors allow ..... which is sorta why I use them. ;o)

Al


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RE: Container Soils - Water Movement & Retention XII

Thank you Al for such a quick response. I was hoping for a detailed response and as always you delivered in easy to understand terms!

This definitely helps clear things up.


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RE: Container Soils - Water Movement & Retention XII

al,
the reason i said "i was wondering if there was some transmission of knowledge that occurs in class that wasnt making it into printed instructions." was because virtually every write-up of testing for soil porosity was part of a college class, or in a textbook. until i saw the photo in your link, i did not realize by saturated they meant so much water that some water was showing above the soil level in places. i think students see it done in person, and do not just rely on these write-ups.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Jan 23, 11 at 16:44

Ahh! The volume of water it takes to fully saturate a given volume of dry soil and have water showing at an equal height with the soil is the measure of total porosity and is a constant, regardless of container size/shape/depth. The difference between that measurement and the water content after as much water that will drain, does drain, through a hole in the bottom of the container, gives us air porosity at container capacity, which is NOT a constant - it varies by container shape and depth.

Al


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RE: Container Soils - Water Movement & Retention XII

Al, I've been wondering about this: If small particles less than 1/8" are what, in essence, cause the PWT to exist in a container, if a bag of potting soil (assuming it is not Miracle-Gro, Hyponex, or something made of 70% sedge peat/peatmoss) is taken and sifted through 1/16" insect screen, will the result be similar to the 5-1-1 mix (discounting nutrients), except that it will break down faster?


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Jan 23, 11 at 20:48

First, you'd prolly lose 90% of the mix, and what would be left would be largely pieces of sticks & clumps of moss, unless the soil had a considerable presence of pine bark in it, in which case why not START with bark if that's what you're after?

It's almost like comparing apples & oranges, but not quite. The 5:1:1 mix holds a lot of it's moisture in tiny pores in the bark, leaving a lot of macropores between park and perlite particles open. I suppose if the pieces you ended up with were rigid and made of bark instead of twigs or sapwood, there would be enough similarity to make your statement pretty accurate, but I can think of a lot of 'buts' and 'ifs'.

It's almost like 'one of those things that are interesting to contemplate, but pretty hard to get excited about testing or implementing'.

Al


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RE: Container Soils - Water Movement & Retention XII

I have a philodendron cutting that I am rooting in water. When I pot it, do I initially want to have a high water table since it was basically submerged in water? Why didn't/doesn't the plant suffocate in water?

Nathan


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Mon, Jan 24, 11 at 21:31

No - you don't want a high water table. Plants that you root in water don't suffocate because they develop a type of tissue that allows the leaves & top of the plant to provide the O2 the plant needs for root function. The problem is, the plant won't transition well from water to soil.

This is something I wrote before. It has more details in it:

Though roots form readily and often seemingly more quickly on many plants propagated in water, the roots produced are quite different from those produced in a soil-like or highly aerated medium (perlite - screened Turface - calcined DE - seed starting mix, e.g.). Physiologically, you will find these roots to be much more brittle than normal roots due to a much higher percentage of aerenchyma (a tissue with a greater percentage of intercellular air spaces than normal parenchyma).

Aerenchyma tissue is filled with airy compartments. It usually forms in already rooted plants as a result of highly selective cell death and dissolution in the root cortex in response to hypoxic conditions in the rhizosphere (root zone). There are 2 types of aerenchymous tissue. One type is formed by cell differentiation and subsequent collapse, and the other type is formed by cell separation without collapse ( as in water-rooted plants). In both cases, the long continuous air spaces allow diffusion of oxygen (and probably ethylene) from shoots to roots that would normally be unavailable to plants with roots growing in hypoxic media. In fresh cuttings placed in water, aerenchymous tissue forms due to the same hypoxic conditions w/o cell death & dissolution.

Note too, that under hypoxic (airless - low O2 levels) conditions, ethylene is necessary for aerenchyma to form. This parallels the fact that low oxygen concentrations, as found in water rooting, generally stimulate trees (I'm a tree guy) and other plants to produce ethylene. For a long while it was believed that high levels of ethylene stimulate adventitious root formation, but lots of recent research proves the reverse to be true. Under hypoxic conditions, like submergence in water, ethylene actually slows down adventitious root formation and elongation.

If you wish to eventually plant your rooted cuttings in soil, it is probably best not to root them in water because of the frequent difficulty in transplanting them to soil. The brittle "water-formed" roots often break during transplant & those that don't break are very poor at water absorption and often die. The effect is equivalent to beginning the cutting process over again with a cutting in which vitality has likely been reduced.

If you do a side by side comparison of cuttings rooted in water & cuttings rooted in soil, the cuttings in soil will always (for an extremely high percentage of plants) have a leg up in development on those moved from water to a soil medium for the reasons outlined above.

Al


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RE: Container Soils - Water Movement & Retention XII

I'm planning to try a slightly modified Al's 5-1-1 mix on my container grown vegetables this year and have some more questions. I've had pretty good results for many years growing mostly tomatoes, peppers & eggplants in 20 to 25 gallon Smart Pots using a mix of 3 parts Metro Mix 500 (predominately pine bark fines) to 1 part my own yard waste compost with Osmocote Plus 15-9-12 with all micros. I've fertilized every 3-4 weeks with Tomatotone. Main problem has been keeping them hydrated in mid- to late summer when temps are in the 90s. This year I'd like to make the plunge. I found a mulch company where I can purchase pine bark fines for less than $2 a cubic foot. My question: I need 42 cu. ft. mix and will have about 12 cu. ft. of compost. Could I use a mix of my compost (instead of peat), 26 cu. ft. Pine fines and 4 cu. ft. perlite? I like to use the Osmocote because early summer is so wet here that I usually don't water until July. After that I often have to water 2-4 times a week. My budget and available hand watering time are tight, but I could switch to a liquid feed instead of granular in July. (I am worried about water retention, hence the compost.) What do you think of my plan?


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Tue, Jan 25, 11 at 9:54

It sounds sound ;o) - should work fine. Much depends on what you end up with for pine bark (size), but if the bark looks anything like what you see at 3,6,or 9 below (the middle pile is what my dry 5:1:1 looks like when done), I would limit the total compost to under 15%. If you find that doesn't give you the water retention you need, you might as well stick with what you've been doing. Both the 5:1:1 mix and the gritty mix are designed such that when you build them to take advantage of the increased aeration, you usually make a commitment to more frequent watering. From the plant's perspective, that's a very good thing, but from the growers perspective, it might possibly impose an inconvenience too great to tolerate.

You can use larger containers w/o over-potting, which allows much better growth, and there is greater potential for growth in highly aerated soils, but the difference between a highly aerated soil like the 5:1:1 mix and something like MG decreases as the planting matures and as water is used faster so air can return faster to the heavier soils. I didn't say that eventually they will be equal, they won't, the better aerated soil offers much greater potential, as long as you're ok with increased watering demands.

I don't even notice the extra watering. In summer, I have to 'make the rounds' of all the containers every day anyway, so even if I'm watering twice as many plants each day than I would be if I was growing in a heavy soil, it doesn't take any where near twice as long. I'm willing to exert a little more time and effort (I mean - tending plants is something I love, so I want to be as good at it as I can be) in my pursuit of some sort of excellence in my growing abilities. Most of the people here feel the same way. They want to learn about other options and discover what's going on with their plants so they can decide what's appropriate to apply to how they want to grow.

If you think there might be anything else I might be able to add, to help you decide what you want to do - you know where to find me. ;o)

Best luck!

Photobucket

Al


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RE: Container Soils - Water Movement & Retention XII

  • Posted by jodik 5 Central IL (My Page) on
    Tue, Jan 25, 11 at 12:55

I agree with Al... for me, the little bit of extra effort is nothing compared to the benefits and joy of working closely with my plants. I did find that the watering was a little different than I was used to, and I had to re-learn, so to speak... but the results are well worth that effort.

So far, I'm only using a version of the gritty mix indoors, but I do have plans to expand my use of it this coming spring to include my deciduous trees and other outside plantings. I'm looking forward to getting out there in the thick of it!


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RE: Container Soils - Water Movement & Retention XII

Thank you Al, and thanks to the many others in this forum who have shared their experiences applying Al's formulas in their growing. I will take your advice and keep the compost to no more than 15 percent of my mix.

I do have another question, of course. ; ) As a tree person, I am hoping you are familiar with the Smart Pots I am using. They are made of fabric that seems a little like felt. I am told that they air prune roots and, when placed on bare earth, can wick moisture and create capillary action between the pot and the ground. You said at beginning of this thread:

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 in the container to a few inches below the bottom of the pot, or allow it to contact soil below the container where the earth acts as a giant wick and will absorb all or most of the perched water in the container, in most cases.

My question is: Would using a Smart Pot with your mix reduce or eliminate the perched water table level? Would this be similar to using a huge wick? And if it is, would that change any of your advice about what to use in the mix?


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Wed, Jan 26, 11 at 15:25

"My question is: Would using a Smart Pot with your mix reduce or eliminate the perched water table level? Would this be similar to using a huge wick? And if it is, would that change any of your advice about what to use in the mix?"

It should eliminate perched water if the Smartpot is in contact with soil below the pot. This employs the earth as a giant wick, so you can get away with using finer soils than toy could if it was a conventional container.

Yes, I think I would shoot for something a little finer than the 5:1:1 mix. I think what would be IDEAL, is if you could find Fafard's Aged Pine bark, and use that at 5:1:1. Technically, from a hydrological view, if your Smartpots' bottoms are in contact with the ground, they are mini raised beds.

The think is, it sounds like you'll have no worry about ant PWT, so you might as well go finer and take advantage of the extra water retention. A good measure of builders sand might be helpful.

It's difficult to tell you specifically what to do, because everything pretty much hinges on what your bake size is.

Al


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Correction ....

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Wed, Jan 26, 11 at 16:51

That's 'BARK size', not 'bake size'. ;o)

Al


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RE: Container Soils - Water Movement & Retention XII

Hi Al,

I had a follow-up question on the watering frequency topic. As background I've got the gritty mix in about 7 containers now (slow but rewarding progress). I'm also using a wick on each of the containers for additional insurance and as a guage to help me identify when to water next.

As the gritty mix has no perched water table, especially with the wick in place, and it is almost always aerated as you pointed out, what would be the harm in watering more frequently? It basically feels like I'm playing a risky game letting the gritty mix go almost completely dry before I water it again. Almost like I'm waiting to fill up the gas tank just before it reaches empty.

You had mentioned the story of the Mr. Oki espousing that you should wait until the plant becomes completely dry and then to water the day before. What happens when the soil drys out? Does this impact the roots negatively and/or does it hit the finer roots harder? Outside of arid plants, do plants need a period of "dryness" in the soil mixture? Or is that advice more so from people trying to get rid of the perched water table?

Maybe I'm looking at this wrong. I have no doubt you will put me back on the right course! I guess it gets confusing because I see so many plant tags that espouse an "evenly" most soil. If that is the case, with the gritty mix and its unique properties, I would think you could water more often, maybe when the gas tank got down to a 1/3 as opposed to letting it go all the way to empty.

Thanks in advance!


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Thu, Jan 27, 11 at 22:52

"As the gritty mix has no perched water table, especially with the wick in place, and it is almost always aerated as you pointed out, what would be the harm in watering more frequently? It basically feels like I'm playing a risky game letting the gritty mix go almost completely dry before I water it again."

It is possible to over-water the gritty mix - especially if you work at it. What feels dry to you isn't necessarily dry to the plant. Plants can usually extract about another 15% of the moisture held in soils AFTER they feel dry to the touch. Because the wick is exposed to the air and the soil in the pot isn't, when the wick first feels dry, there is still quite a bit of moisture in the soil.

You'll be surprised at how much water the gritty mix holds when you've become used to it. I often leave a volunteer weed growing in my juniper and pine bonsai as a 'tell', to let me know when to water. When the weed wilts, it's time for a drink.

Ideally, you would water immediately before the plant experiences any stress from drought. With many plants, you can watch for wilting, which is an indication you've waited a little too long, but to do that occasionally gives you a good idea about how much water the soil holds. Also, try testing with a sharpened dowel if you're anxious about the wick as a 'tell'.

Some plants prefer a completely dry soil during periods of dormancy or quiescence. Completely dry soil kills roots. The drier the soil becomes, the larger the roots are that succumb to dehydration. Water is required for photosynthesis, and a byproduct of photosynthesis is the hormone auxin. A stead supply of auxin moving through what is called the abscission zone at the base of leaves is required to keep an abscission layer from forming. No water = no photosynthesis = no auxin flow across the abscission zone = abscission layer forming = abscission (shedding) of leaves. This is the plant's drought response in preparation for what it 'thinks' is an upcoming consequential dormancy. The things that cause this drought response most often are over-fertilizing or a high level of salts in the soil, under-watering, over-watering. In many plants, a sudden or drastic (over time) decrease in photo-intensity or photo-period can cause enough of a decrease in auxin flow to cause the same reaction via a different mechanism.

Most plants in active growth do not ever want a period of dryness, for the reasons listed above. Sometimes it is required to cause certain physiological changes in the plant that WE approve of (like blooming), but the plant would normally always prefer a supply of water during active growth. This is kind of a gray area because I'm sure there are cacti/succulent experts out there that might disagree (maybe not - I don't know), and I don't know enough about the physiology of cacti to press forward on the point, so I wouldn't argue. I don't grow a ton of cacti, or anything too unusual, but everything I HAVE grown has responded well to treatment based on what I just shared with you, but for your trees, herbaceous plants, veggies ....... what I said holds true.

You DO have much more latitude when it comes to watering and fertilizing fast soils. They are far more forgiving, and don't deprive roots of O2, either 'at all' or 'for as long as' heavier, peat/compost/coir-based soils.

Plants don't drink water. They absorb it molecule by molecule from the thin coating on colloidal surfaces, so think damp or moist instead of wet, and you'll be fine. I don't remember where you live, but by the middle of summer you'll be an expert. It's pretty easy after you get over the initial shock most people have.

I did a presentation to a large Master Gardener's Club last night, and toward the end of the talk when the questions were flying, they started turning toward soils. I really didn't lead the discussion there, other than to explain the type of soils bonsai were grown in and to pass around a sample of the gritty mix. What actually turned the discussion to soils/fertilizing/PWTs, was the fact that one of the bonsai I took had a wick dangling from the drain hole. When one of the ladies asked about it, I explained about PWTs and heavy soils. Just like this thread - I could see 'the light' go on in soo many people's eyes. My talk ran 20 minutes over the allotted hour, and people kept me for another 45 minutes asking questions.

I'm scheduled to give a talk FOR this MG group to the public at some kind of shindig they have planned in June, and have agreed to do several other programs (to be determined) within the next year or so. It was a fun night. I knew a LOT of the people, so the atmosphere was really warm & friendly - a great time.

I wish all of you guys could have been there. Actually, the president of the club had seen a presentation I did for the MG club she USED (we used) to belong to, and wants me to do that one for this club, too. I'm looking forward to THAT presentation even more than I was the one last night.

Sorry to be so long-winded again, but when I see people embracing a new concept - and so willingly, it's pretty exciting, so I wanted to share ....

Al


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  • Posted by filix z5 maine (My Page) on
    Fri, Jan 28, 11 at 6:33

Hi Al. You gave me a lighter version of the gritty. "What I asked for". Using perlite in place of granite. I forgot to ask you, do I add gypsum? And at the same ratio? Many thanks. filix.


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Jan 28, 11 at 9:53

Read your fertilizer label. If it has neither Ca nor Mg, use gypsum & Epsom salts (ask about the Epsom salts if you don't remember). If it contains Mg but not Ca, use gypsum. If it contains both Ca & Mg, (Foliage-Pro), there is probably no need for gypsum. I grew 5 different plants in the gritty mix w/o gypsum last summer, using 9-3-6, and all did very well.

Al


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RE: Container Soils - Water Movement & Retention XII

Al,

I am thinking about using a product called RootTrapper instead of a plastic pot. It's a fabric container that is laminated on the outside with the bottom two inches left unlamented for draining. (I read thread XI and XII and the only similar post was about the SmartPots.)

I will be growing a large amount of plum trees outside for about 5 years. I was thinking about the gritty mix because you said that it is best for trees and for longer periods of time. I was also thinking about not screening the ingredients because the fabric inside could act like a wick and I also have to make about 3 tons of mix (screening would be a major pain).

I am also unsure on how large of a pot to use. I am thinking 10 or 15 gallon. Do you have any suggestions on the soil mix, if you think I�ll have problems with PWT, and pot size?

Thanks so much,
Tim


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Jan 28, 11 at 16:19

Why are you growing these trees for so long in containers? Are you buying liners or propagating yourself? How will you handle watering chores? Will the containers be resting on bare earth or be in close contact with soil that allows drainage?

Al


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RE: Container Soils - Water Movement & Retention XII

Excellent response Al. I love the detail. The 'moist' analogy definitely helped. I think I have a better handle on it now.

Thanks!


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RE: Container Soils - Water Movement & Retention XII

Al,

I plan to move the trees eventually so I figure it would be easier than planting them in the ground and digging them back up. I am buying the trees at 1-3' tall. I will grow about 150 this year and plan to water by hand (water hose) for now. The RootTrapper containers will be in direct contact with ground that drains well.

I've never done anything like this before and I'm still trying to piece together a plan. Any suggestions would be very helpful.

Thanks again,
Tim


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Jan 28, 11 at 21:20

Essentially, you're growing in mini raised beds, so you can use a much finer soil than would be advisable in conventional containers (the earth is your wick, so a PWT should never be a consideration).

You could probably do well with the largest fraction of the soil being builder's sand with a lesser presence of bark fines and a little sphagnum peat thrown in (reduces shrinkage as the organic fraction decomposes - 5 years is a long time in 1 container). The soil I mentioned will be much less expensive than the gritty mix, and much easier to keep moist in your application.

Al


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RE: Container Soils - Water Movement & Retention XII

You totally rock Al. Thanks for helping me and so many others.

Tim


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Jan 29, 11 at 9:41

Photobucket


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RE: Container Soils - Water Movement & Retention XII

Hey Al,
I have a question about screening bark. I recently purchased 1 yard of fine pine bark and have started screening through it. I start with 1/2 wire and what's left over I toss out.Then I go to 1/4 wire after I sift it I take what is left in my sreening box and put it in a container for griity mix and the real fine bark and dust that fell in my catch pan I use for 511. Does this sound about right or should I screen the fine stuff again through bug screen and get rid of all the dust and add whats left to my griity bark bucket? Also should I be concerned with the little small pieces of would that is mixed in with the bark, it really isn't a lot. Sorry for all the silly questions I'm kinda new at all of this. Thanks Ray


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Jan 30, 11 at 11:56

I start with 1/2 wire and what's left over I toss out. How about tossing it on your garden or beds, or adding it to your compost pile?

For the 5:1:1 mix, dust to 3/8 is best, but if you have some 1/2" pieces in there, don't sweat it.

For the gritty mix, I like 1/8-1/4 fir bark, because the particles aren't flat, like pine bark. If you're using pine bark, I would save what does go through a 3/8" screen and doesn't go through a 1/8" screen, and use that in the mix.

Photobucket

You can see that some of the particles are about 3/4 the size of the dime.

Al


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RE: Container Soils - Water Movement & Retention XII

Thanks Al,

I'm using pine bark cause there is a local nursery supplier that grinds bark,and I got a whole yard for $25. I will have to locate some different size screen, all I have is 1/2",1/4", and some insect screen. I toss the 1/2 bark into a seperate pile to use on some of my wifes flower beds, I dont actually throw it away.


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Jan 30, 11 at 16:34

OK - sounds like you have things going your way - especially the price on the bark! ;o)

Al


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RE: Container Soils - Water Movement & Retention XII

Al
When I am making my 511 I sift my bark through 1/4" hardware cloth and use everything that falls through. I have a lot of dust material in with the bark should I try and sift a little of that out or just leave it with the bark. I know you said the best size for 511 is dust to 1/4" but it seems like there is a bunch of dust.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Jan 30, 11 at 21:23

Dust to 3/8 (and just a little larger is fine, too) is best. If you find yourself using mostly the very fine particles, leave the peat out & even up the perlite a little if you need to. The idea is to start with a large fraction of larger particles then add smaller particles to adjust water retention. You're actually not ADDING them back in, except in the case of perlite. You could actually use everything that goes through a 3/8 or even a 1/2" screen.

Al


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RE: Container Soils - Water Movement & Retention XII

Ok Thanks Al. I have been trying to locate some 3/8" screen, any suggestions on where I might can locate some.


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RE: Container Soils - Water Movement & Retention XII

Try a hardware store - sold as "hardware cloth."

Josh


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RE: Container Soils - Water Movement & Retention XII

Yea I know its called hardware cloth. I just havent been able to find any in the 3/8 size at any of my local hardware stores.


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RE: Container Soils - Water Movement & Retention XII

Well this might be a dumb question but I have only had time to skim over some of these Water Movement & Retention posts so no fair laughing. There is only so much coffee I can drink and so many posts I can read in a day. :)

I have lots of pine bark mulch left from last season and several bags of very coarse sand, not the kids play sand, but large, BB size or bigger pieces, almost like very fine gravel. I'm wondering if I could make a good container soil from just those two materials? I think I would have to screen the large pieces and fine dust out of the pine bark, and the very small pieces of sand, but would those two things make a good soil?

I have a lot more reading to do so just wanted to ask.

Thanks!


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Wed, Feb 9, 11 at 20:57

Size IS important ..... when it comes to container soils. If your sand has a lot of particles in the 1'8" size range, it might be worth saving what DOES pass through 1/8" and what doesn't pass through insect screen for the gritty mix. You're probably better off using perlite for any 5:1:1 mix you make. You can scroll up the thread, look at the pictures & read about the appropriate sizes of bark for each mix. We'll wait while you're reading & be ready to answer all your questions when you're done. ;o)

Good luck, Margo. See you back soon.

Al


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RE: Container Soils - Water Movement & Retention XII

Hi all! There is some wonderful information here. Many thanks to al and all who post here. Question about watering the gritty mix - do you completely saturate it each time and let excess drain out or do you put enough so it just begins to drain out bottom?
Thanks! Amy


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Mon, Feb 14, 11 at 18:47

I completely saturate each time so at least 10-15% of the water I apply exits the drain hole. In the summer, when everything is outdoors, I use the hose & water fast, until water starts to drain out the bottom. I don't wet foliage. In winter, for indoor plants. I have a watering can that I fitted with a nozzle I made. It restricts water flow so I'm watering slower than with the hose. I direct the water all over the surface of the soil. Much is absorbed, but when water starts appearing from the drain hole and collecting in the catch saucer, I water just a little more. The water drips out for a minute or two, but I'm still flushing the soil in the winter.

Try to arrange your pots so they set well above the effluent. That way the salts you're flushing from the soil can't make their way back up into the container.

Good luck! Help is just a post away whenever you need it.

I don't remember if I wished you a Happy Valentine's Day on your thread or not. If I didn't, I'm wishing you one now. ;o) Happy Valentine's Day, Amy.

Al


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RE: Container Soils - Water Movement & Retention XII

I am going to make both the 5-1-1 mix and the gritty mix for different plants. I think I've found a good source for pine bark fines (apparently uncomposted), but I won't be sure until the place opens for the season and I can actually look at it instead of just looking at a picture. The place, Ohio Mulch, also sells #9 gravel and mason sand. I am wondering if the gravel would be an acceptable substitute for gran-i-grit in the gritty mix?

I also asked a question above about what components I should use for my 5-1-1 mix in Smart Pots, which you compared to mini-raised beds in your answer (Jan. 26). You said, "A good measure of builders sand might be helpful." Ohio Mulch also sells "mason sand." Is that the same as builders sand? Should I substitute builders sand for some or all of the perlite? Or would I add it to the 5-1-1 mix?

Here is a link that might be useful: Ohio source of pine bark fines, gravel and sand


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Feb 18, 11 at 15:37

You might find the #9 gravel small. Let its physical size be your guide. You want the pieces to be from about 3/32-3/16.

Builder's/mason's/torpedo sand are interchangeable or like Kleenex/tissue - different names for the same product. If your bags will be in contact with the ground, you can eliminate the perlite & add at least 2 parts of sand to the bark, along with the 1 part of peat.

Al


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RE: Container Soils - Water Movement & Retention XII

So, if I understand you correctly, I can use 5 parts pine bark fines, 1 part peat and 2 parts mason/builders sand in my "mini-raised bed" type pots? Very cool! Thank you! Count me as one more of your big time fans.


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Feb 18, 11 at 16:11

Yes - you can probably even use more sand than that if you wish - especially if it's nice & coarse.

I appreciate your kind comment. Still, I'll be hoping we can get past the 'fan' thing & move right along to 'friends'. :-)

Have a good weekend!

Al


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RE: Container Soils - Water Movement & Retention XII

It's a deal. I'd be honored to be your friend. :-) I didn't mean to gush. I am just so appreciative of how patient you are in answering almost the same questions again and again. (I've read most of the previous 11 threads on this subject.) And I'm so excited about applying what I've learned here to my plants.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Feb 18, 11 at 22:59

Just know that your excitement and enthusiasm fuels that of others. I know it fuels mine. Every fall, I'm garden-worn from a really busy summer, but then come the enthusiastic and determined like you, and here I am only a couple of months later, itching for the snow to go so I can get into the gardens. I always admire those who want to learn new things and those who work to improve their skills. For a new friend, I'm richer. Any time you think there might be something I can help you with, don't hesitate. If I can help, I will.

Take care.

Al


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I've always said that gardening and patience go hand in hand... but Al takes it to a new level! :-)

I've been excited since I first discovered Al's writings! Everything is so well written, so factual and logical... so well explained... that it makes me sit on pins and needles every winter, awaiting spring's arrival so I can dig in and start mixing medium, re-potting, start the whole growing adventure all over again!

We fuel each other, I think... and the excitement and ensuing enjoyment are contagious! We can't help but share what we've learned, share our experiences, and share our successes!

It's gonna be a great season... I can tell already! :-)


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I couldn't agree more with everything you said Jodi!

And it's so nice to have new people here, new excitement, and we all continue to learn, and new friendships grow!

It's going to be a great season!

Wishing everyone a speedy spring!
JoJo


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RE: Container Soils - Water Movement & Retention XII

I hear you jodik and Jojo about spring. I can't wait! It's snowing and windy in Cincinnati, oh today. I'm so ready for spring. I have a couple of houseplants in gritty mix already and am employing the use of wooden skewers to help me figure out when to water. It's not as radically different as I thought. Lucky for me they are small enough I can take them to kitchen sink, water and let drain out. It feels good to " know" when mix is dry and know how much fertilizer is in mix. That is something I have always guessed about in past.
I am really happy to have found the gritty mix and be able to see everyones elses success and received help from so many of you as I begin my journey.
Thanks again!

Amy


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Feb 25, 11 at 8:11

One of the reasons I enjoy this forum so much is, almost everyone takes great interest (almost like a responsibility willingly shouldered) in seeing that you have the information and encouragement you need to succeed. It's fun to be around people like that; and fun to be around people like you who just 'soak it all up'.

Take care, Amy.

Al


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Hello All,

I've spent two days reading over all these posts, I'm very excited about Al's Gritty Mix. I have inside and outside containers that I started to redo a year ago before a injury put it all on hold. I had pulled out some plants that were dying in large containers (3'x2') outside in a Whitney Farms mix, and inside I had started to repot a few container in a mix of Turface, perlite and core, about a 1-1-1 mix (not sifted). So now we are a year later and I'm ready to start again and I know what hasn't been working this last year and started searching online and ran across this thread. So here are my questions and anyone with an idea I would appreciate any help.

I live on the coast in California, wind from the ocean blows across my backyard everyday, pots outside are usually watered once a week to twice in summer. Potting soils have uneven moisture, dry out in spots, shrink, or they turn to muck. The Gritty Mix sounds great but I was wondering if I were to replace the granite with perlite if that would help me retain more moisture between waterings? I do short travels sometimes and there isn't always someone who is willing to come water more than once a week.

My other question is concerning indoor plants, and a few outdoor hanging plants. I have to be able to take my container plants to the sink counter to water, they can be to heavy depending on how my back is. The Gritty Mix sounds great but I'm afraid it will make these container to heavy and to heavy for a few outdoor hanging plants. Anyone have idea's for lightening up the Gritty Mix but keeping the core intension?

Thanks for any help, I'm looking forward to a great year of repotting and healthier plants,

Jerry


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  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Feb 26, 11 at 16:31

You can use screened perlite to replace a fraction or all of the granite to increase water retention, or just increase the amount of screened Turface with a commensurate decrease in the amount of granite. The gritty mix is designed to be 'adjustable' for water retention.

Everyone thinks the gritty mix is heavy because the granite is heavy, but the gritty mix holds much less water than water-retentive soils, so at container capacity (when the soil is fully saturated) the gritty mix is actually only about 25% heavier than soils like Miracle-Gro.

If that's still an issue, lighten it up by substituting screened perlite for some of the granite, or use the 5:1:1 mix, which will be quite a bit lighter than peat-based soils at container capacity.

Don't forget that this thread is more about selling you on a concept than it is about selling you on a particular soil recipe. I've just offered what I consider the best ways to implement that concept by sharing recipes, but there is nothing that says you need to adhere to them exactly. As long as you understand how important particle size is to the way the gritty mix was intended to function, and have a little understanding of why the ingredients I selected for my own soils work so well, you can feel free to experiment with other ingredients on your own.

Best luck!!

Al


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RE: Container Soils - Water Movement & Retention XII

I finally found pine bark fines that look perfect at $2 per cubic foot! I've been looking for a couple weeks, but found that possible sources within 50 miles of my home were all closed for the season. This morning I stopped by a small family-owned nursery and garden center that has been closed on weekends until now. There were no pine bark fines on display, so I asked the owner if he would be getting any in. He said, "We have a lot if it out at the farm because we use it in our potting mixes for our big planters and nursery stock." I told him about the 511 mix I wanted to make, and how it was made primarily of pine bark fines, and he laughed. He said, "That's an old nursery man's secret recipe," and began telling me how much better it was than the expensive peat-based mixes he stocks because that's what his customers demand. I've been shopping at this store for years and no one ever suggested that paying $20 for 2 cf of peat based mix was not only bad for my plants, but also bad for my pocket book. When I pointed that out, he told me no one ever asked his advice about what to use before.


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RE: Container Soils - Water Movement & Retention XII

Hello Everyone...

I just wanted to say "THANK YOU" to AL..for him not giving up on helping me find my source for pine bark fines....You have been so kind to help me. I certainly appreciate everything that you have done for me...Many thanks my friend!!!

Today i had the pleasure of meeting a fine gentleman who gladly brought me 3 bags from a different city since he was traveling to Norfolk for a Bonsai exhibit. He was such a great joy to talk to as well as "listen" to what he has done to his trees and the different types of soils that he uses...People really do care and it shows through the way that they want to help us fellow plant enthusiast!!

It really makes me believe that people who share in their knowledge as well as people want to help others are people that "give from the heart"...It truly made my day (which i really needed..)and it closes the "hunt" for my ingredients for my "mix". I am a very "happy camper!!!"

Now i will wait for a few days or weeks to start my production line for my trees/plants...I cant wait to get started...

Temps here in VB have started to change..today 50..tomorrow around 60...but the night time temps are going to be below 32*...I cant bring anything outside yet...and my temporary greenhouse has been on hold for awhile...so Plumies will have to wait for a few more weeks to go outside..here is a pic of my plumerias wanting to start to wake up...

Photobucket

Thanks to everyone who has offered help to me...you all are the best...Thank You...

Laura in VB : )


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Feb 26, 11 at 22:36

Robin & Laura - I'm really glad for you both .... and your enthusiasm has made me smile. :-) I hope you'll stick around & keep us posted on how you fare. It's always fun to get the impressions of those new to the highly aerated soils.
Photobucket

Al


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RE: Container Soils - Water Movement & Retention XII

There seems to be a substitution of coconut fiber/coir whatever it is called for sphagnum in pre-mixed products, I don't think I like the idea. I suppose you can cut back on adding lime. Which would you prefer if you had the choice?


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RE: Container Soils - Water Movement & Retention XII

I too am so vey happy for you!!! Look at you all go everyone!

I knew that you would all get excited about your journeys as I did, and get the help you needed too! That is why I am always referring many here.

Laura, I am very proud of you sticking with your plan and doing what ever it took to find what you needed!
I love the way your plumeria look. Oh they look so nice. I too have to set a line production of all mine into the gritty mix with bigger containers. Mine too are all resting and can't come out until I can put them into my pop up and let the temps get as hot as they want in there.

Al, as ALWAYS, I too appreciate all you have done for me, and for my many friends! Thank you:-0))))

Please, watch for Jessica, since she too would love to experience all the excitement around here...

Hi Jerry, I never met, and anyone else I might of missed including those dear to me. Gotta run.

Mike:-0)))


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sun, Feb 27, 11 at 11:34

Woebegonia (I like that name - very clever) - I don't like coir as a significant fraction of any mix. I wrote this a while ago & I think it is a good explanation as to why I prefer peat over coir and conifer bark over CHCs:

Sphagnum peat and coir have nearly identical water retention curves. They both retain about 90-95% of their volume in water at saturation and release it over approximately the same curve until they both lock water up so tightly it's unavailable for plant uptake at about 30-33% saturation. Coir actually has less loft than sphagnum peat, and therefore, less aeration. Because of this propensity, coir should be used in mixes at lower %s than peat. Because of the tendency to compact, in the greenhouse industry, coir is primarily used in containers in sub-irrigation (bottom-watering) situations. Many sources produce coir that is high in soluble salts, so this can also be an issue.

Using coir as the primary component of container media virtually eliminates lime or dolomitic lime as a possible Ca source because of coir's high pH (6+). Gypsum should be used as a Ca source, which eliminates coir's low S content. All coir products are very high in K, very low in Ca, and have a potentially high Mn content, which can interfere with the uptake of Fe.
I haven't tested coir thoroughly, but I have done some testing of CHCs (coconut husk chips) with some loose controls in place. After very thoroughly leaching and rinsing the chips, I made a 5:1:1 soil of pine bark:peat:perlite (which I know to be very productive) and a 5:1:1 mix of CHCs:peat:perlite. I planted 6 cuttings of snapdragon and 6 cuttings of Coleus (each from the same plant to help reduce genetic influences) in containers (same size/shape) of the different soils. I added dolomitic lime to the bark soil and gypsum to the CHC soil. After the cuttings struck, I eliminated all but the three strongest in each of the 4 containers. I watered each container with a weak solution of MG 12-4-8 with STEM added at each watering, and watered on an 'as needed basis', not on a schedule. The only difference in the fertilizer regimen was the fact that I included a small amount of MgSO4 (Epsom salts) to provide MG (the dolomitic lime in the bark soil contained the MG, while the gypsum (CaSO4) in the CHC soil did not. This difference was necessary because or the high pH of CHCs and coir.) for the CHC soil.

The results were startling. In both cases, the cuttings grown in the CHC's exhibited only about 1/2 the biomass at summers end as the plants in the bark mix.

I just find it very difficult for a solid case to be made (besides "It works for me") for the use of coir or CHC's. They're more expensive and more difficult to use effectively. The fact that some believe peat is in short supply (no where near true, btw) is easily offset by the effect of the carbon footprint of coir in its trek to the US from Sri Lanka or other exotic locales.
That's the view from here. YMMV

Al


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RE: Container Soils - Water Movement & Retention XII

I second Al's view... I've had personal experience with cococoir/peat, and I'll never use it again! It's way too quick to compact, and even the pre-rinsed coir holds an amount of harmful saline. It also grew the strangest molds I've ever seen, and held moisture for way too long a span of time. I lost a few amaryllids to rot using the coco peat.

After having used the Gritty Mix, I can say with all honesty that I much prefer the fir bark/perlite/turface/granite chip medium mix for my indoor plants. It puts me in control of moisture and nutrition... and it's not a "water in sips" or a waiting game while the medium dries out from total saturation, drowning roots!

I have yet to use the bark/peat/perlite mix for my outdoor containers, but I trust Al's experiences and I know that it'll net me the good results I'm after.



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RE: Container Soils - Water Movement & Retention XII

Thank you, now I know what I am up against and I can think things over.


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RE: Container Soils - Water Movement & Retention XII

Dear all,

Been a reader for a while by new to the posting. Sorry for the long post here. Saw Laura's plumerias and decided to poll the group.

I'm very intrigued by the 5:1:1 and "gritty" and was trying to determine how best to use each. I'd have a few active discussions with fellow co-workers about this too, and I'd appreciate the feedback from you fine folks here.

My indoor plants vary greatly from plumeria, to various cacti/succulents (barrel cactus, Sempervivum, Haworthia), african violets, holiday cactus (Schlumbergera and Rhipsalidopsis), Alpinia, and Curcuma? If yes, what do you think would be best?

Has anyone had success with orchids, esp. laeliocattleya, bletilla, or calanthe? A close friend has who has grown orchids for years thinks this mix may not be ideal.

Also, has anyone tried bone meal instead of the lime/gypsum?

Thanks for the help.


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RE: Container Soils - Water Movement & Retention XII

Welcome!

I grow cacti and succulents such as Jades and Euphorbia and Desert Rose in the Gritty Mix.

Junge Cacti, such as Christmas Cactus, I grow in a mix that is very similar to the 5-1-1.
I have African Violets, Orchid, and Hoyas growing in the 5-1-1, as well.

I would not recommend bone meal as a substitute for lime/gypsum.


Josh


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Wed, Mar 2, 11 at 21:01

The soils are essentially interchangeable, but the guideline I use runs to how long I expect that individual planting to go between repots. By 'repot', I mean a full repot, which includes removing old soil and reducing the root mass of most plants, sometimes dividing certain plantings.

If a planting is seasonal, like veggies and mixed floral display plantings of plants we treat as annuals, I usually always opt for the 5:1:1 mix. It's less expensive and there is very little concern for breakdown in a years time. Often, I'll extend the interval of some plantings in the 5:1:1 mix to 2 years. I impose the 2 year limit on myself not because the soil will only remain serviceable for two years, it retains its structure FAR longer than other soils based on peat/compost/coir and other fine organic particulates, it's just that I'm fussy about my soils AND the intervals between repots. Plant growth and vitality begin to be negatively affected at about the point where the soil/root mass can be lifted from the container intact. If the planting is allowed to become additionally root-bound beyond that point, the planting has to have the root condition corrected by a full repot or it will be permanently affected.

Everything I grow long term goes in the gritty mix. All my houseplants, C&S, and woody material I'm growing on for bonsai are repotted into the gritty mix at the first opportunity. Properly made, the gritty mix holds good amounts of water w/o holding perched water, which is the water in soils that kills roots, causing the cyclic death and regeneration of fine roots after soils are saturated. The gritty mix is designed to eliminate this cycle that saps energy as roots that are paid for die and the plant is charged with paying for roots being newly generated from the plant's energy reserves, reserves that might have gone into producing more fruit, blooms, foliage, or simply increasing biomass.

For all intents and purposes, bone meal breaks down so slowly in containers it has no effect on pH or nutrient levels. I tend to me minimalistic in what I include in my soils aimed at supplying nutrients, adding nothing that might upset the balance of the 3:1:2 ratio fertilizers I almost always use. As an example, if you are using Foliage-Pro 9-3-6, it supplies all 12 essential nutrients in as close to the exact proportions that plants use that you're likely to find in a commercial product. Anything else you add, whether it's extra Fe, P, N ..... is going to be an excess. Liebig's Law of the Minimum recognizes an excess of any potential limiting factor as as potentially limiting as a deficiency.

It makes the best sense to use dolomite, which supplies both Ca and Mg in a favorable ratio to supply these elements and adjust the pH of the 5:1:1 mix. The gritty mix comes in at a higher pH than the 5:1:1 mix, so we generally only add gypsum as a Ca source when our soluble fertilizer lacks Ca. This usually requires the addition of a little Epsom salts in the fertilizer solution each time you fertilize. More on that if necessary once your course is plotted.

Al


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RE: Container Soils - Water Movement & Retention XII

Thanks for your comments Josh. Wondering how often you re-pot your plants (see also Al's subsequent post). In the case of the Junge Cacti, how do you deal with container size since I thought many of these types of plants prefer a more restricted environment(spacial crowding as in their natural habitat)?


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RE2: Container Soils - Water Movement & Retention XII

Al,

Thanks for your message. As a scientist (but not botanist) I appreciate your methodologies and thoughtful approach. I do have a few follow-up questions that I hope you don't mind addressing.

I have seen from posts here that there are different fertilizers that could be used. My aim is to try and naturally apply nutrients/minerals through supplementation that reflect a plant's natural habitat while trying to have such nutrients exist in the best form possible. As an analogy, complex carbohydrates provide a more sustained nutrient level to animals than do simple sugars. How can I achieve this when moving to the "gritty" or 5:1:1? Obviously, the presence of compost is not such a good idea in containers, so how do I best mimic this intent?

Can you provide any measured "soil" pH for either the gritty or 5:1:1. If you need a more acidic environment for a particular plant, would you use garden sulfur (and if so, how), or do you add something in liquid form during fertilizing/watering.

Thanks again.


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RE: Container Soils - Water Movement & Retention XII

I grow a few orchids in the Gritty Mix, mainly Dendrobiums... and the majority of my plant collection consists of bulbs... amaryllids, mainly.

I vary the ingredients and the ratios used depending on plant type, placement, and other variables. The Dens are in a mix consisting of more bark than turface or granite... the bulbs are in a fairly equal mix of all ingredients... I don't want to have to re-pot often, so the gritty mix works great for my uses.

Since container growing varies so differently from growing in the ground, I stick with a more inorganic approach, both in medium and in nutrition. I use nothing more than Miracle Gro liquid with the addition of STEM micro-nutrients, to ensure my plants get what they require.

I think all plants would spread out their roots comfortably if they could... and potting them tightly only puts them into stress, whereby they bloom or offset in anticipation of pending death due to those stresses. So, the fallacy that being potbound is preferable to some plants... I just don't buy. The beauty of a faster draining medium is it allows larger pots to be used because there's no or minimal perched water. The medium doesn't remain saturated, thus drowning or suffocating important root structure.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Thu, Mar 3, 11 at 15:26

Jodi is right - from a physiological perspective, no plant likes tight roots - if they did, Mother Nature would have arranged for their roots to grow in tight little geometric shapes immediately under the stems. You can read more about why plants don't prefer to be rootbound if you follow the embedded link. You can use the added stress that rootbound conditions create to bend the plant to your will in some cases, but it's important to realize that from the plant's perspective, any stress is a negative and impacts growth/vitality.

Even though there is little difference between the way our body actually handles simple vs complex carbohydrates (other than speed), I can probably take the nomer of 'complex carbohydrate' to mean 'digestible saccharide' that exists in whole foods and that also includes vitamins, minerals, fiber .... contrasting with the processed carbohydrates we often refer to as 'empty calories'. Am I on the right track, here?

I think our goals are divergent, but let me propose something after I make a few observations. Containers are radically different than gardens. What works well in gardens is often a disaster in a container, For example, using topsoil in containers can usually be relied upon to produce very poor results. Mixing compost into the topsoil as a nutrient source or to improve soil structure is usually a disaster. Micro-organism populations are reliably boom/or bust in containers, so delivery of nutrients is erratic and unreliable. Using organic soil amendments as a nutrient source, like various meals, often has a negative impact on soil structure, and usually wondering what we've applied and when it will be available.

Soluble fertilizers, on the other hand, can be applied as often as you prefer. You can maintain a very precise level of nutrients in the soil, and control the RATIO of nutrients, one to the other, at all times. This is of great benefit if your goal is plant vitality or best growth. In gardens, we can almost get away entirely with only 'feeding the soil', but in container culture, we actually benefit from NOT feeding the soil - from NOT adding things that break down quickly, promoting huge populations of microorganisms that also break down the soil particles, destroying the soils structure, which is key in container culture.

I achieve a steady and even supply of nutrients in the winter by fertilizing all the indoor plants with a low dose every time I water. It works exceptionally well. I would maintain this same regimen in summer if I had the time, but with more than 300 containers to tend each year, I would only be able to take the time to fertilize every time I water if I used an injection system. Instead, I usually fertilize weekly by hand at about 1/2 the recommended dose, depending on temperatures. If it's above 85* or below 55*, I usually withhold fertilizer until the weather changes. This would be especially true if using urea/ammonia-based fertilizers.

Finally - the only realistic way for container gardeners to manage pH is by managing the pH of their irrigation/fertigation water. Vinegar or citric acid can be added to your water to neutralize alkalinity and bring the pH down to a target level. Once the volume required is established, adding the same amount of the acidifying compound to the water each time you irrigate/fertigate allows you to maintain pH within your desired range.

Al


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RE: Container Soils - Water Movement & Retention XII

Al is right on! Solid information flows from his fingertips ;-)

Howdy, Greenthumb, I usually re-pot after one or two years...or sooner if the roots
have totally colonized the mix. The Jungle Cacti grow in any size container that I choose,
and they thrive! I have them in large terracotta, and I have them in moderately sized plastic, as well.
With bark-based mix, I root cuttings in the container in which I intend to grow them.

As Jodi and Al explained, plants don't like or prefer restricted roots.


Josh


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RE: Container Soils - Water Movement & Retention XII

Dear all,

Thanks for all of your valuable input. I'm intrigued by the comments posted, and have more questions.

Jodik, would you be willing to provide me with some idea of the proportions used with your orchid care, or direct me where I may start? From the various posts and threads, it seems the gritty mix is forgiving, but I'd appreciate the insights regardless.

Obviously there will be a learning curve to watering with either the gritty or 5:1:1, or any modification for that matter. How essential is the wick to the newcomer in learning when to water, and when not? If you don't use a wick, and as an example, a plant sits in full sun outdoors in the NE, what should one be looking for? It seems that wet to the touch doesn't work.

Also, in thinking about bulbs, or other plants that require drier conditions, or that can be forced (like amaryllis), how does one adapt the watering conditions? How do you deal with rest periods, such as the case for a wintering plumeria?

In response to Al's message, there is a clear difference between the container and the garden. I appreciate the insights about nutrient administration. I know there are lots of myths that need to be debunked before I am truly successful. Maybe I should start each post with a disclaimer about my gardening knowledge being only a few truths and many myths.

I suspect that within Al's comment regarding nutrient consistency and availability in containers, he touched on a principle that seems a crucial foundation for a successful outcome. I can speak from my experience regarding the irregular results I've observed using more of a "soil." I've been concerned about drainage and aeration but until more recently, haven't started to appreciate the troublesome conditions I have been creating.

Another personal myth I've been lead to believe and that I now need to break is that gardeners who use defined soluble fertilizers are not taking short-cuts in not "feeding the soil" but may in fact be thinking about consistent nutrient/mineral delivery, ESPECIALLY when working with containers. I have always liked the concepts of robustness and repeatability, and it seems all of you have done sufficient experiments already to help lead me to believe otherwise.

I'd like to start a new thread about nutrients/feeding/fertilizer? What does everyone think -- sufficient benefit to others? (It's also a bit off topic from water movement, and I'd like to keep the focus for this one.) Obviously I would need lots of help here from you, since you have already done so much of the hard work. :) If not, I can always post again here.

Again, thanks for your various posts, and wishing you all happy gardening.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Mar 4, 11 at 15:54

If the gritty mix is properly made, a wick is just insurance for the newbie who can't imagine that the gritty mix holds any water, given the speed with which water flows through the soil. Until they get their mind wrapped around the idea that it holds much more water than they think, the wick can serve as an instant remedy to a heavy watering hand, or as a 'tell' that will indicate when it's ok to water (when the wick is dry where it emerges from the pot).

Maybe Jodi will include more insight when she talks about her bulbs, but I don't treat resting plants in the gritty mix any differently than I would treat them in another mix - other than to perhaps water a little more frequently. The highly porous soil does dry down faster than heavier soils.

"I can speak from my experience regarding the irregular results I've observed using more of a "soil." I've been concerned about drainage and aeration but until more recently, haven't started to appreciate the troublesome conditions I have been creating."

I'll say 'good', but only from the perspective that it leaves you open to considering alternatives. I've never suggested that the free-draining soils I and many others are using are for everyone - though they CAN be, for anyone willing to go to the effort of gathering the materials & mixing the soils. Once sources are found, the largest drawback is the increased watering frequency. These soils definitely offer greater opportunity for your plants to grow as near as possible to their genetic potential, defining the question as, "Do I want to sacrifice a little convenience for greater opportunity for better plant performance?" Since I'm BEING fair, I don't feel bashful about saying that the soils offer much greater latitude and margin for error in the areas of reducing over-watering and decreasing the likelihood of fertilizing mistakes.

I don't look at soluble fertilizers as a convenient way to avoid "all the things you need to do to have a healthy garden'. On the contrary - I think that for the results oriented, not only are soluble fertilizers are the most efficacious way to get nutrients to plants, allowing the grower complete control over exactly what his plants get and exactly when they get it, but we can take advantage of a stroke of luck in that it also happens to be the easiest way, by far. It is really only when ideology or politics comes to play that we hear anything negative about soluble fertilizers for container culture. To be sure, I strongly believe in feeding the soil in my gardens & beds, fertilizing minimally if at all and relying primarily on compost and mulch to build soil health and nutrient content; but I've found that if I leave that concept in the garden and not try to export it from there to my containers, I'm much better off.

Start a new thread if you wish. I don't know if you read it or not, but this discussion about fertilizer strategies for containers should answer a lot of your questions. Feel free to piggyback on that thread, or start your own if you feel that would serve your purpose better.

Thank you for the kind words. I'll look forward to helping and/or offering insight where I can.

Al



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RE: Container Soils - Water Movement & Retention XII

Sure, Greenthumb... let me preface by saying, while I consider myself a novice orchid grower, I've actually been dabbling in growing one plant type or another since I was quite young. If I had met Al 40 years ago, I'd be so much further along in my success and enjoyment of gardening, both indoors and outdoors!

Anyway, I find it important to know what each ingredient brings to the mix... as example, turface brings a certain amount of water retention, granite is inert and simply adds to the overall volume of larger particulate, creating the desired air pockets, etc... and since bark is widely used for orchid growing, it seemed logical to make it the main ingredient in my orchid medium. It, too, holds a certain amount of moisture, but I'd say not as much as turface, and by its very shape would be perfect for orchid roots, which behave as they do.

However, since my home environment is overly dry, lacking humidity to a very big extent, I want some moisture retention. So, I use a little turface, and I use the fir bark in larger quantities than the granite chips, turface and perlite. I keep the fir bark the majority ingredient by volume for orchids. How much, exactly? I don't really know... I eyeball it as I mix. I wish I could be precise, but I just can't.

Most of my container growing occurs indoors, and most is in pots between 2" and say, 12" or a bit larger. For my orchids, I try to use opaque or clear pots so I can see the roots and condensation inside the pot. This helps me know when moisture levels are high or low. The skewer method also helps.

Because I grow most of my indoor plants in smaller containers, I only need to mix small batches of medium at any one time. You'll get a feel for how much of each ingredient to add to a batch, depending upon variables such as moisture retention, the plant type and its requirements, your individual environment, where you place the container, sun or shade, etc...

There is a learning curve to the gritty mix, but it's not as difficult as a few people would have you believe. In a given situation, you may have to water more often... and you may not. It greatly depends upon the plant, its requirements, your climate and environment, etc... all the usual variables. Plants should be watered as they need moisture, and not weekly or bi-weekly or on any set schedule, as some unknowing growers are wont to do.

Where do you start with ingredients? Right here, in this very thread, with the basic recipes. Think about the concept of the mix, what each ingredient offers, their relationship to each other within the mix, which recipe you'll be using... most growers, it seems, use the 511 for outdoor use and the gritty mix for indoor use, or the 511 for shorter term plantings and the gritty for longer term plantings... the plant type you're growing, and the environment in which you'll be growing in.

It's wise to begin with an easy plant and the basic recipe, and learn the ins and outs of caring for it in the gritty mix or the 511, and then move on to other plant types once you're familiar with it. I began by potting a Sanseveria and a few Hippeastrum bulbs in it, and once I was comfortable with its care, moved on to re-potting my orchids and my rarer Amaryllids.

The first myth we have to get past is that there's such a thing as a green thumb... that gardening is luck and you can either grow or you can't. That's nonsense. A green thumb is nothing more than knowledge. A successful grower knows that the application of knowledge brings success, that learning the basic science of how plants grow and what they need... learning the "how" and the "why" of it all will net us the best results.

The second myth is that all growing is the same. Not true. Growing within the confines of a container is vastly different than growing in the ground. The abridged version is that outdoors, in the garden, Mother Nature provides a balance of good and bad, and a vast army of living creatures and micro-organisms that work in diligent harmony to decompose, to break down matter into usable nutrition for plants. This same army and balance is nigh impossible to maintain within the small space of a container, and the balance is all too quickly thrown off, most often leading to plant death and disaster.

I'll add a third myth... that the commercial industry works for gardeners. Not true. Like any other industry, its main objective is profit. If they provided us with the mediums plants preferred and the knowledge to grow all the plants sold, they'd quickly be out of business. Some plants can live and thrive for generations with proper care. Take the art of bonsai, as example... some of those trees are hundreds of years old! No repeat business there!

Just remember that knowledge holds the keys to your success, and through that success, your enjoyment of growing... and you'll do just fine! What's more important to you? Growing to your, and the plants' potential? Or convenience?

I hope this gives you some things to think about... I read through the article contained at the beginning of this thread several times before it all came together for me, and I understood what it was I had been doing wrong all these years. I even copied and pasted the article, along with the recipes for the mixes, to my desktop so I could refer to it from time to time. It's really helped me a lot.

Al writes in such a wonderfully simple style, explaining everything in detail from a layman's perspective... so anyone can grasp the basics of how plants grow and what they need, and their relationship to soils and water, and how it all behaves together in a container environment.

Sorry to have written such a book... but I type as I think, and I didn't want to forget anything. :-) Even so, I'm sure I have. Oh, and as for feeding my plants, I do so using an all-purpose liquid plant food, and adding micro-nutrients to ensure good health. I dilute the liquid to about 1/4 or less of the recommended strength, and I water with it every time my plants need watering... about 3 out of 4 times, actually... and on the 4th time, I flush with clear water to ensure there's no buildup of salts within the medium.

The beauty of the larger particled, grittier mixes is that there's a much wider margin for watering error, and YOU are in complete control of moisture, nutrition, flushing, etc... you control it all. I like that. No guessing. :-)


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Mar 4, 11 at 17:43

Very nicely said, Jodi.

Thanks for the kind words ..... and thanks for all the effort you put into your post. ;o)

Al


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RE: Container Soils - Water Movement & Retention XII

Al & Jodi,

Appreciate your feedback. Certainly is plenty to think through if the plan is to be implemented properly. I've started to make the shopping list, and am still working though volumes I may need, and how to properly screen the material. I know I've seen much of the info here already, but as was just said, I just need to look back over the info again and again till it all clicks.

I think (perhaps like others?) that I underestimated the unique behavior and properties of the container vs. the outdoor garden. If thought about in the proper context, as many of you here are doing, there can be repeated successes due more to control than chance/luck.

I'm sure more questions to follow, but for now a thanks to you both. I'd be nice to hear others' success and difficulties too.

Although I had just found the link (to the fertilizer info) that Al posted a few minutes before I read the post above, thanks for the link!


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Fri, Mar 4, 11 at 21:42

Full disclosure: The downside is in the fact that you have to locate sources for suitable ingredients and sometimes screen them (mainly for the gritty mix). For most of us, that inconvenience is offset by the fact that the soils are of such superior quality to most commercial bagged soils and they cost about half as much on a per volume basis as bagged soils. They do require more frequent watering, but from the plant's perspective, that's a good thing. Frequent watering means frequent purging of gasses from the root zone. Additionally, there is a direct correlation between increased drainage/aeration and watering intervals, such that those soils that DO require more frequent watering are virtually assured to offer a better opportunity for plants to flourish.

Occasionally you'll find someone with a difficulty adapting to one of these mixes. Usually, it will be because substitutions or additions were made to 'improve' the mix before they were even familiar with it, or something wasn't screened - things like that. Occasionally, someone in a very hot/dry climate will find they aren't willing to or can't keep up with watering demands, but by & large the reaction has been overwhelmingly positive.

Al


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RE: Container Soils - Water Movement & Retention XII

Thanks, Al... when you compliment my writing, it means a lot. It means I understand what you've been teaching, and I'm ready to move on to more complicated knowledge! :-)

We're all only too happy to help, Greenthumb. It gives me pleasure to think that something I've shared can benefit another grower.

The more you read all the basic info, the more it will click. I can promise you that! For me, it was like a light bulb suddenly lighting up, and I thought, "wow! How could I have not known some of this?!" Most of it is common sense, when you think about it, and very scientifically sound and logical. It all makes perfect sense!

The next step is implementing what we've learned. I begun by trying to locate the proper ingredients to try the gritty mix... and let me tell you right up front that you won't get much help from the commercial/retail gardening industry! What you will get are some mighty blank looks when you ask about fir bark or turface! Sales clerks will wonder what the heck you could possibly want with such items, and why you'd want to build a soil when bagged dirt is stacked right there. They'll direct you to all kinds of items, most not what you're looking for.

So, locating what you really want right off the bat may be more difficult than you'd think, but don't give up the ship! Chances are good one of us can direct you to places near you that carry the right ingredients, and there's a thread here in the forum somewhere that addresses locating the various items.

This is what I use... ZooMed ReptiBark reptile bedding, which is 100% screened, dust free fir bark, available at PetsMart... Manna Pro poultry grit, which is 100% granite chips, though it requires rinsing to remove dust, available at Farm & Fleet or farm oriented stores... coarse perlite, screening required, available anywhere... and turface, screening required, available through the local John Deere dealer.

This is a photo of the fir bark and granite chip bags I get...
Photobucket

This is what the ingredients look like... starting left/top and working clockwise... turface, perlite, fir bark, and granite chips...
Photobucket

The quarter is for size comparison. You'll notice that the ingredients are all comparable in size, with the bark being slightly larger. Some fine orchid barks are smaller, and might suit you better... it depends on the usual variables, and what you are able to locate.

Once the great group of folks get through with you here, you should be all set up, but in case you can't locate something, other ideas to consider are looking at bonsai growers, orchid growers, mulch companies, garden centers... and NAPA even carries a floor dry product for oil spills that can be substituted for the turface. Some calcined baked clay cat litters might work, as well, though they should be tested to check for durability. But we can cross that bridge if and when we get to it.

I would recommend Foliage Pro as the fertilizer of choice, though Miracle Gro liquid or other comparable all purpose fertilizer will work just fine. The addition of micro-nutrients may be necessary with some fertilizers.

Let's see... what am I forgetting? Well, you'll probably want to pick up some wooden skewers... they come 100 to a pack, available at your local grocery store for about a buck. Wicking, I'm not sure about. I don't use it. It's a good idea, especially with larger pots, though. I'm sure Al can tell us what he recommends. Screens for sifting ingredients... I'm not sure where to get those, either... I use insect screen and a colander that has the right mesh size, but I'm sure others can recommend that, too... and screening for the drainage holes in pots, to keep the mix from dribbling out... that can be as simple as the mesh used for needlepoint, available anywhere sewing and craft items are sold.

So, now you've got a shopping list. Let the treasure hunt begin! And please, feel free to ask any questions you may have... we're all more than happy to help. :-)



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RE: Container Soils - Water Movement & Retention XII

Hello again,

My #3 perlite will be in on Tuesday, I have my fir bark, just got back with two bags of Turface MVP, so today will be a day of sifting. I opened a bag of Turface and put a couple scoops in the 1/8 sifter just to see what sifted out, I was suprised how much, I bet 50% went through so I stopped shaken the sifter, seems like a waste, I don't have garden beds to put it in.

Any thoughts? Maybe I don't need to sift out every little piece, I did notice some of the pics people have posted seem to have some smaller pieces of Turface or perlite in them. Maybe I'm being to precise?

Just in case someone was going to ask, I'm not using grit, I'm using the perlite instead. I have a back injury and my house plants need to be as light as I can get them so that I can carry them to the sink. My outside container plants and tree's I will probably do a combo of perlite & pumice with the bark and Turface because I need the added moisture. I live on the coast in S. California and the wind blows up the hill everyday drying the container plants out, and when the hot Santa Ana winds blow, well that's a whole nother story.

I have enough perlite to get me by, so I'm repoting something today!

Jerry


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RE: Container Soils - Water Movement & Retention XII

Hi Jerry,
1/8" is too big for screening turface. You can use insect screen. I also use it to screen the dust and fines out of the perlite.

I'm using perlite for my gritty mix at the moment too. I can't find the grit here.

The amounts do change a little if using perlite. Here's what Al suggests.

It is suggested~
4 screened perlite
3 screened bark
2 screened Turface

will be about the same water retention as the original

1 screened bark
1 screened Turface
1 crushed granite (grower size) or #2 cherrystone

Adjust as required from there.

I'm trying to sift today, anxious to get some tree's done, but wind is making it not fun. lol!

Good luck with your re potting today.

JoJo


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Mar 5, 11 at 15:17

What JJ said.

Al


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RE: Container Soils - Water Movement & Retention XII

Thank you so much JoJo, I knew I was missing something, I knew I was seeing smaller particles in some of the pictures. I was wondering though, if the granite only holds the water on it's surface, then why would you need to change the ratio and have more perlite to hold more moisture when by it's nature it is porous? Is it because it's in smaller particles? I'm going to mix it in the quantity you suggest, I'm just an eager apprentice.

Thank you to all of you, I've learned so much in the past couple weeks, everyone around me is sick of hearing me talk about soil.

Jerry


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Mar 5, 11 at 16:10

Lolol - everyone around HERE is sick of me talking about soil too, but the questions and people with difficulties related to their soils just keep coming.

Got the question covered JJ?

Al


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RE: Container Soils - Water Movement & Retention XII

Ok, so I tried the insect screen, that left a lot more in the pan, but they're smaller than a bb. From what I read above, wouldn't that be like the bb's in the pudding? I thought I was supposed to get everything to be between 1/8-1/4? If there are to many particles of the Turface and perlite that are smaller than the bark, and there percentage is greater than the sum of the bark, doesn't that clog things up?

I keep reading the first part above, sorry for all the questions. I would just do what you say, and I am, but I just like to understand why something is, or done a certain way. I don't want to make to many mistakes.

Jerry


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Sat, Mar 5, 11 at 18:28

Screening the Turface through insect screen leaves you with the Turface being a little smaller than Ideal, but it's something I'm willing to live with because the other properties are so great. If I could find a calcined clay in a size just a smidgen larger, I'd be all over it. However, since the granite and bark I use are slightly larger than the Turface and still small enough that the mix remains homogeneous, water won't perch. IF the granite is too small & the bark too large, as in what happened to Julie, you WILL get perched water and more water retention than what you want. Still, it will be less water retention and a lower PWT than in peaty soils, but too much to be considered ideal. The ideal soil holds lots of water but no perched water.

In a perfect world, the Turface and granite would be just under 1/8" to just over 1/8", and the bark 1/8-1/4" to allow for some breakdown over time.

I use Turface screened through insect screen and #2 cherrystone, which is prescreened 1/8-3/16", and 1/8-1/4" prescreened fir bark and I get no perched water at all.

A little perched water to me is a big deal because I grow a LOT of material in shallow containers, but it won't be as significant to those growing in deeper containers like nursery cans. If you're concerned, you can always add a wick and make it a nonissue.

Al


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RE: Container Soils - Water Movement & Retention XII

Good morning to all.

I'd like some more info about the soil longevity for the various mixes as suggested at the start of the post so I can plan how much material I need for pilot experiments. ["I have seen advice that some highly organic (practically speaking - almost all container soils are highly organic) container soils are productive for up to 5 years or more. I disagree and will explain why if there is interest."] If there is already a thread/link, please let me know where to find. Can some/any of the components be re-used? What can be done with the spent mixture(s)?

Would someone please provide a quick recap of the "right" type of bark vs the "wrong" type. (I understand the size range I am after.) I like the idea of the pre-screened ReptiBark, but wonder if there are more cost effective strategies if I know the right information. Also, what screening methods do people use that are easy to get/make and widely available?

Thanks again.


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RE: Container Soils - Water Movement & Retention XII

General gardening knowledge and common sense tell me that any highly organic soil cannot possibly remain viable for a span of 5 years as container medium, due to basic decomposition of the organic matter it's comprised of. In fact, compaction of fine particles happens swiftly, and I wouldn't use a bagged organic soil for more than one growing season... if I used it, at all. Knowing, as I do, that there is a great difference between growing in the ground, and growing within the confines of containers, I avoid organic in pots and save it for the beds outside.

In the gritty mix, the one ingredient that will eventually break down is the fir bark, and that can take quite a long time. Al can explain how long it will take, and why... that bit of information escapes me at the moment. I'm looking at using a batch of gritty mix for at least 3 years before re-potting.

I would screen the spent mixture, removing the finer particulate, and re-use what portion still looked viable. The spent part will be spread over my outdoor raised beds. Or, I could simply dump all of it on my raised beds and work it in, which will help aeration, and begin anew for my containers. It will depend largely upon my gardening budget at the time.

ReptiBark is not cost effective if large amounts are required. It would be more prudent to locate a bulk fir bark item in a "fine" size.

If you're handy, nice screens can be made using insect screening, or the screen size of choice, and a wooden frame. You can make it to fit whatever receptacle you'll be screening over and storing the material in. Or, you can purchase ready made bonsai screens, though they would impede quick screening of bulk items due to their smaller size.

I'm sure someone will be along shortly to give information on where to get screening, and to answer other questions that I can't, or that I've forgotten. The above is how I'd do it, though.



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starting seeds for container veggies?

Hi All,

What awesome info to have stumbled upon! Thanks Al and everyone!

I'm hoping someone can answer a question for me.
So this is my first season gardening and I'm planning on using containers. I plan to start seeds this week, and a few days ago (before reading this thread!) I bought a bag of some organic seed starting mix (that I now plan to return, I think...?) My question is this: Is the 5-1-1 mix suitable for starting seeds for veggies? And for growing strawberries too? (Or do I hold onto the seed starting mix I bought?)
I'm thinkin' the answer is to use the 5-1-1 mix from the get-go, but I don't really know, ya know?!

Thanks much and be well,
AprilAugust


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RE: Container Soils - Water Movement & Retention XII

Hello, April!

We're glad to have you. Welcome aboard!

First, strawberries will do wonderfully in the 5-1-1. I just saw a good buddy's strawberries
in 5-1-1 under grow-lights last night. He has them in 4-inch containers and he already has berries.

Secondly, I use the Gritty Mix to start my seeds: peppers, squash, melon, maple, osage, castor bean.
As the seedlings grow larger, I transfer them into 5-1-1 to take advantage of the slightly increased
moisture retention.


Josh


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RE: Container Soils - Water Movement & Retention XII

Hi, There is a product on Fafard's website called Organic Soil Conditioner, made of processed pine bark, limestone, and gypsum. Is this ok for the 511 mix? If it is, do I still need to add the lime? My brain is spinning right now and I think I saw in a thread that this is good for the 511. There are several Fafard retailers in my area. I'm having no luck "yet" with finding the pine bark fines, but I still have a lot of searching left to do. If this Fafard product isn't usable, does anyone know of a source in the Syracuse NY area for the pine bark fines? Thanks.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Mon, Mar 14, 11 at 19:28

I've never seen it or used it. Fafard's soil blends #51L or #3 are both pine bark-based soils and pretty good right out of the bale, though. I have used Fafard's aged pine bark in soils, and for me it's borderline too fine. It's so fine you would probably want to forgo the peat and even add a little extra perlite to it.

Al


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RE: Container Soils - Water Movement & Retention XII

OK, I really appreciate the advice. Well.....back to the drawing board. It's still very early in the season up here and most garden centers, big boxes, and Walmarts aren't even set up for spring. Who know's what they'll eventually get in. I don't need the 511 'til May 1st at the earliest. I'm sure something will turn up. There is a big mulch place a short drive from here that has hemlock bark mulch. I noticed that you said hemlock is ok to use. Thanks.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Mon, Mar 14, 11 at 20:10

Lol - you've been doing your homework (hemlock). I like the positive attitude, too!

Al


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RE: Container Soils - Water Movement & Retention XII

FWI, I just ordered a 2 cu. ft. bag of perlite online from Home Depot for $17 + tax, w/free shipping. I thought that was a pretty good price.


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Tue, Mar 15, 11 at 15:05

Not sure I should say anything, but I buy 4 cu ft bags for $10.50 (at least that's what they were last year). If I had room & thought I could ever use it, it's also available in a 60 cu ft bag @ $105.

Al


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RE: Container Soils - Water Movement & Retention XII

No problem, I knew I was leading with my chin in some respects with that one, but for around here that was the best I found after quite a lot of looking. Hopefully it will help someone else. I hope I don't see it too much cheaper in the near future. No buyers remorse "yet." So is your source online? I'm DEFINITELY still in the market for some inexpensive pine bark fines:) That's the last piece of the puzzle. I'll buy a bunch of pine bark mulch and run over it with my truck a bunch of times if I have to. Lol. I must know someone with a chipper, I just haven't figured out who yet. I think using my wife's food processor to chip the bark is out of the question:)


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Tue, Mar 15, 11 at 17:57

I have a wholesaler that supplies nurseries with all sorts of products about a half hour away. With a business license, I buy wholesale.

'Al-Par Peat' in Elsie, MI is the company I get it from. I buy some CRF fertilizers & peat bales from them, too. For years, I used to buy pine bark from them too (cheap), but lately they've been carrying this stuff with ground peanut shells and rice hulls in it & I don't care for it.

Good luck! ;-)

Al


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RE: Container Soils - Water Movement & Retention XII

I paid $13 for my 2 cu. ft. bag at Home Depot, commercial grade.


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RE: Container Soils - Water Movement & Retention XII

Hi,

Just curious, I have a question about sphagnum peat vs sphagnum moss. By mistake, I purchased sphagnum moss at the onset of making the 511 mix. I mixed one batch and used it for one of my 3 plants.

When I realized that I was using the moss instead of the sphagnum peat, I threw it out and purchased the correct one and used it to make the mix for the other 2 plants I have.

My question is this, is it possible that the presence of the sphagnum moss in this one container could somehow attract any pests?

The reason I ask is that I saw about a couple of black, winged, fast-moving pests (maybe thrips or gnats?) around this plant today.

Upon further inspection, I shuffled some of the top mix and saw a single, tiny larva(e) crawling in the medium and suspected that I have pests breeding in my container.

And afterwards, as I shook the container, a fast crawling, winged pest climbed out of the mix, and up the side of the container. I sprayed this plant with some insecticdal soap and plan on repotting it using the sphagnum peat moss instead.

So could this (sphagnum moss) be the reason for pest-sightings? I want to solve a potential big problem now, before the real bug season begins.

By the way, I haven't watered this plant for like a week and it still seems to be moist inside. I had watered every 3 days prior to the last time.


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RE: Container Soils - Water Movement & Retention XII

What kine of bark did you start with Sam?

Did it already have some fines in it? If so, that along with the peat fraction will hold way to much moisture and will certainly be a breeding ground for fungus gnats. Good catch:-)

Mike


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RE: Container Soils - Water Movement & Retention XII

Al, Which bark would be better to use for the 5:1:1 mixture? I might have 2 choices. Pure Hemlock bark, and the second is a mixture of White Pine bark, Red pine bark, and Spruce bark. Thanks, Ed


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Wed, Mar 16, 11 at 14:20

I used chipped hemlock bark I got from a local mill a long time ago, and it worked ok. I've never used spruce though, so I can't really say which would be better. Sorry. I wouldn't think there would be a significant difference in the chemical composition, though. I would probably let the texture be my guide & take whichever one fits the most favorable size profile.

Al


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RE: Container Soils - Water Movement & Retention XII

OK, thanks. I'll be giving the stuff a looksee next week. To be continued....


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RE: Container Soils - Water Movement & Retention XII

I used repti- bark in the mix. Is the sphagnum moss bad for the mix though? I wanted to know if I should repot with the sphagnum peat instead?


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RE: Container Soils - Water Movement & Retention XII

Honestly. Sam, I never use peat with repti-bark.

I only use ingredients roughly about the same size such as turface and or granite. I am not sure if using such fine particles as moss, I think is almost dust, can settle into an area that collects to much moisture that is much finer and more dense than the repti-bark.

Maybe someone her can answer this.

I tend to use decomposted bark with peat for my 5.1.1 so it mixes well and dries out evenly, although this too retains more moisture by nature.

I can tell you that fungus gnats do not breed well in uncomposted bark such as repti-bark, but they may love the fine moss where that has settled between the bigger bark spaces.


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RE: Container Soils - Water Movement & Retention XII

Hello Al.

I am getting ready to start making my mixes, I am going to be using the gritty and the 511 mixes for my indoor and outdoor plants. I do have a few questions.

On an earlier post that I can't find again (probably because I have read so many posts here in the last couple of weeks I lost track of it) someone asked you questions about a bark mulch called 'Greensmix Bark Mulch' carried at Lows. My Lows carries it as well. Will it be suitable for both the gritty mix and the 511? The bark size is up to 3/8".

Turface is not available in my area, I shall be using the NAPA oil dry. Can I use it instead of the perlite in the 511 mix? I believe it will retain more moisture, but as I live in a dry area this would be a good thing.

I believe I read in a post that if I am using a complete fertilizer like Foliage Pro that I would not have to use the lime in the 511 or the gypsum in the gritty. Is this true?

Ruth


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Thu, Mar 17, 11 at 15:34

If the Greensmix is pine bark and dust to 3/8, it should be perfect for the 5:1:1 mix. You should be able to screen it and use it for the gritty mix too, if you like, and use the leftover fines in the 5:1:1 mix - no waste. ;-)

If you use the floor dry in lieu of perlite, you might want to go a little easier on the peat fraction, but you'll ultimately have to be the judge of that.

DO use lime in the 5:1:1 with FP 9-3-6, but don't use gypsum in the gritty mix, or add Epsom salts to the fertilizer solution.

Would you hold any replies until I get set up with the next thread? This thread is about to top out at 150 posts, and I'd like to link the last post here to the new thread, and that might take me a half hr or so to get it set up. Thanks!

Al


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RE: Container Soils - Water Movement & Retention XII

  • Posted by tapla z5b-6a mid-MI (My Page) on
    Thu, Mar 17, 11 at 16:11

Please follow the link to the continuation of this thread. It will take you to Part XIII

Thanks to everyone for being a part of making this thread so much fun for all of us!

Al


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