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Container Soils - Water Movement and Retention XIX

I guess I wasn't paying close enough attention to the last thread. I like to leave a link at the end of the previous to the new thread, which would be this one.

Container Soils - Water Movement and Retention XIX
I first posted this thread back in March of '05. So far, it has reached the maximum number of posts GW allows to a single thread eighteen times, 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 reinforcement of hundreds of participants over the years that strongly suggests the information provided in good-spirited collective exchange has made a significant difference in the quality of their growing experience. I'll provide links to some of the more recent of the previous dozen threads and nearly 2,500 posts at the end of what I have written - just 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, and the time you invest results in a significantly improved growing experience.
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 information.

Before we get started, I'd like to mention that I wrote a reply and posted it to a thread recently, and I think it is well worth considering. It not only sets a minimum standard for what constitutes a 'GOOD' soil, but also points to the fact that not all growers look at container soils from the same perspective, which is why growers so often disagree on what makes a 'good' soil. I hope you find it thought provoking:

Is Soil X a 'Good' Soil?

I think any discussion on this topic must largely center around the word "GOOD", and we can broaden the term 'good' so it also includes 'quality' or 'suitable', as in "Is soil X a quality or suitable soil?"

How do we determine if soil A or soil B is a good soil? and before we do that, we'd better decide if we are going to look at it from the plant's perspective or from the grower's perspective, because often there is a considerable amount of conflict to be found in the overlap - so much so that one can often be mutually exclusive of the other.

We can imagine that grower A might not be happy or satisfied unless knows he is squeezing every bit of potential from his plants, and grower Z might not be happy or content unless he can water his plants before leaving on a 2-week jaunt, and still have a weeks worth of not having to water when he returns. Everyone else is somewhere between A and Z; with B, D, F, H, J, L, N, P, R, T, V, X, and Y either unaware of how much difference soil choice can make, or they understand but don't care.

I said all that to illustrate the large measure of futility in trying to establish any sort of standard as to what makes a good soil from the individual grower's perspective; but let's change our focus from the pointless to the possible.

We're only interested in the comparative degrees of 'good' and 'better' here. It would be presumptive to label any soil "best". 'Best I've found' or 'best I've used' CAN sometimes be useful for comparative purposes, but that's a very subjective judgment. Let's tackle 'good', then move on to 'better', and finally see what we can do about qualifying these descriptors so they can apply to all growers.

I would like to think that everyone would prefer to use a soil that can be described as 'good' from the plant's perspective. How do we determine what a plant wants? Surprisingly, we can use %s established by truly scientific studies that are widely accepted in the greenhouse and nursery trades to determine if a soil is good or not good - from the plant's perspective, that is. Rather than use confusing numbers that mean nothing to the hobby grower, I can suggest that our standard for a good soil should be, at a minimum, that you can water that soil properly. That means, that at any time during the growth cycle, you can water your plantings to beyond the point of saturation (so excess water is draining from the pot) without the fear of root rot or compromised root function or metabolism due to (take your pick) too much water or too little air in the root zone.

I think it's very reasonable to withhold the comparative basic descriptor, 'GOOD', from soils that can't be watered properly without compromising root function, or worse, suffering one of the fungaluglies that cause root rot. I also think anyone wishing to make the case from the plant's perspective that a soil that can't be watered to beyond saturation w/o compromising root health can be called 'good', is fighting on the UP side logic hill.

So I contend that 'good' soils are soils we can water correctly; that is, we can flush the soil when we water without concern for compromising root health/function/metabolism. If you ask yourself, "Can I water correctly if I use this soil?" and the answer is 'NO' ... it's not a good soil ... for the reasons stated above.

Can you water correctly using most of the bagged soils readily available? 'NO', I don't think I need to point to a conclusion.

What about 'BETTER'? Can we determine what might make a better soil? Yes, we can. If we start with a soil that meets the minimum standard of 'good', and improve either the physical and/or chemical properties of that soil, or make it last longer, then we have 'better'. Even if we cannot agree on how low we wish to set the bar for what constitutes 'good', we should be able to agree that any soil that reduces excess water retention, increases aeration, ensures increased potential for optimal root health, and lasts longer than soils that only meet some one's individual and arbitrary standard of 'good', is a 'better' soil.

All the plants we grow, unless grown from seed, have the genetic potential to be beautiful specimens. It's easy to say, and easy to see the absolute truth in the idea that if you give a plant everything it wants it will flourish and grow; after all, plants are programmed to grow just that way. Our growing skills are defined by our ability to give plants what they want. The better we are at it, the better our plants will grow. But we all know it's not that easy. Lifetimes are spent in careful study, trying to determine just exactly what it is that plants want and need to make them grow best.

Since this is a soil discussion, let's see what the plant wants from its soil. The plant wants a soil in which we have endeavored to provide in available form, all the essential nutrients, in the ratio in at which the plant uses them, and at a concentration high enough to prevent deficiencies yet low enough to make it easy to take up water (and the nutrients dissolved in the water). First and foremost, though, the plant wants a container soil that is evenly damp, never wet or soggy. Giving a plant what it wants, to flourish and grow, doesn't include a soil that is half saturated for a week before aeration returns to the entire soil mass, even if you only water in small sips. Plants might do 'ok' in some soils, but to actually flourish, like they are genetically programmed to do, they would need to be unencumbered by wet, soggy soils.

We become better growers by improving our ability to reduce the effects of limiting factors, or by eliminating those limiting factors entirely; in other words, by clearing out those influences that stand in the way of the plant reaching its genetic potential. Even if we are able to make every other factor that influences plant growth/vitality absolutely perfect, it could not make up for a substandard soil. For a plant to grow to its genetic potential, every factor has to be perfect, including the soil. Of course, we'll never manage to get to that point, but the good news is that as we get closer and closer, our plants get better and better; and hopefully, we'll get more from our growing experience.

In my travels, I've discovered it almost always ends up being that one little factor that we willingly or unwittingly overlooked that limits us in our abilities, and our plants in their potential.

Food for thought:
A 2-bit plant in a $10 soil has a future full of potential, where a $10 plant in a 2-bit soil has only a future filled with limitations. ~ Al

Container Soils - Water Movement & Retention

As container gardeners, our first priority should be to ensure 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 in 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.

Consider this if you will:

Container soils are all about structure, and particle size plays the primary role in determining whether a soil is suited or unsuited to the application. 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 a nutrient supply in available form sufficient to sustain plant systems. Gas Exchange - it must be amply porous to allow air to move through the root system and gasses that are the by-product of decomposition to escape. Water - it must retain water enough in liquid and/or vapor form to sustain plants between waterings. Air - it must contain a volume of air sufficient to ensure that root function/metabolism/growth is not impaired. This is extremely important and the primary reason that heavy, water-retentive soils are so limiting in their affect. 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 and retention of water in container 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; cohesion is what makes water form drops. 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 .100 (just under 1/8) inch. Perched water is water that occupies a layer of soil at the bottom of containers or above coarse drainage layers that tends to remain 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. Perched water can be tightly held in heavy (comprised of small particles) soils where it perches (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. If 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 and the production of noxious gasses. 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: If using a soil that supports perched water, 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 simply drain better and hold more air. 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?

I already stated I hold as true that the grower's soil choice when establishing a planting for the long term is the most important decision he/she will make. There is no question that the roots are the heart of the plant, and plant vitality is inextricably linked in a hard lock-up with root vitality. In order to get the best from your plants, you absolutely must have happy roots.

If you start with a water-retentive medium, you cannot effectively amend it to improve aeration or drainage characteristics by adding larger particulates. Sand, perlite, Turface, calcined DE ...... none of them will work effectively. To visualize why sand and perlite can't change drainage/aeration, 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 perlite/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 perlite become the largest fraction of the mix (60-75%) that drainage & PWT height begins to improve. At that point, you're growing in perlite amended with a little potting soil.

You cannot add coarse material to fine material and improve drainage or the ht of the PWT. Use the same example as above & replace the pudding with play sand or peat moss or a peat-based potting soil - 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. That can be a considerable benefit, but it makes more sense to approach the problem from an angle that also allows us to increase the aeration AND durability of the soil. That is where Pine bark comes in, and I will get to that soon.

If you want to profit from a soil that offers superior drainage and aeration, you need to start with an ingredient as the basis for your soils that already HAVE those properties, by ensuring that the soil is primarily comprised of particles much larger than those in peat/compost/coir/sand/topsoil, 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.

I fully understand that many are happy with the results they get when using commercially prepared soils, and I'm not trying to get anyone to change anything. My intent is to make sure that those who are having trouble with issues related to soil, understand why the issues occur, that there are options, and what they are.

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 added 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 suffer/die because there is insufficient air at the root zone to insure normal root function, so water/nutrient uptake and root metabolism become seriously impaired.

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 Bark fines of pine, fir or hemlock, 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 - it retains its structure.

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 in any significant volume as well. 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.

The basic soils I use ....

The 5:1:1 mix:

5 parts pine bark fines, dust - 3/8 (size is important
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite (coarse, if you can get it)
garden lime (or gypsum in some cases)
controlled release fertilizer (if preferred)

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)

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)

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 they can grow at as close to their genetic potential within the limits of other cultural factors as possible. 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, VERY 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 screened pine bark, Turface, and crushed granite.

The gritty mix:

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 (eliminate if your fertilizer has Ca)
CRF (if desired)

I use 1/8 -1/4 tsp Epsom salts (MgSO4) per gallon of fertilizer solution when I fertilize if the fertilizer does not contain Mg (check your fertilizer - if it is soluble, it is probable it does not contain Ca or Mg. If I am using my currently favored fertilizer (I use it on everything), Dyna-Gro's Foliage-Pro in the 9-3-6 formulation, and I don't use gypsum or Epsom salts in the fertilizer solution.

If there is interest, you'll find some of the more recent continuations of the thread at the links below:

Post XVIII

Post XVII

Post XVI

Post XV

Post XIV

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

If you do find yourself using soils you feel are too water-retentive, you'll find some Help Dealing with Water Retentive Soils by following this embedded link.

If you happen to be at all curious about How Plant Growth is Limited, just click the embedded link.

Finally, if you are primarily into houseplants, you can find an Overview of the Basics that should provide help in avoiding the most common pitfalls.

As always - best luck. Good growing!! Let me know if you think there is anything I might be able to help you with.

Al

This post was edited by tapla on Tue, Apr 29, 14 at 23:23

Comments (150)

  • neuf
    9 years ago
    last modified: 9 years ago

    Hah! This will surely be the only time I can correct Al...those are "rabbet" or "dado" joints and they are PERFECT for the application.

    After making a small one that I can use indoors, I strongly recommend and I am going to build a larger one with it sized so at least the short sides of a rectangle fit into a wheelbarrow. This, unless your are doing a lot larger batch each time.

    Thanks for all you do for us Al!!!

    Jeff

    This post was edited by neuf on Sat, Jun 14, 14 at 7:21

  • warpiper
    9 years ago
    last modified: 9 years ago

    Thanks Laura, Al, and Jeff,

    1"x4" it is. I'll pick them up today and use rabbit joints to put them together with glue and screw. I already have the screens in 1/16", 1/8", 1/4", and 1/2. That should meet my needs. I was looking at making the screen 2'x2' and either use them over a wheel barrel or a tarp. I hadn't considered using handles on them but it looks like you all have. Does having them make a difference? Thanks, and thanks for the pictures, those are worth a 1000 words. :)

    Chris

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    I guess I went crazzy there for a minute. For accuracy's sake, I'll forever desist from naming it a half lap joint and name it a dado or rabbet joint. ;-) Good catch.

    Al

  • warpiper
    9 years ago
    last modified: 9 years ago

    Ok, here are some pictures of the pine bark fines or triple cut that I picked up today. $30 for a yard. Don't know if that is a good price or not but I have enough to keep me busy for a while. I picked it up at Low Country Mulch in Mt. Pleasant, SC.

    {{gwi:23195}}

    {{gwi:23197}}

  • greenman28 NorCal 7b/8a
    9 years ago
    last modified: 9 years ago

    Good lookin' bark!
    Certainly remove as much of the sapwood as possible, but it's not too bad overall.

    Josh

  • neuf
    9 years ago
    last modified: 9 years ago

    I have been removing as much sapwood as possible when screening, but please explain to me again why it is such an important thing.

    Thanks!

    Jeff

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    That looks like great bark! Glad you found the right type of bark in your area. I'm guessing you are making a batch of 5-1-1 or grit mix as I type this. :)

    FWIW, that pine bark looks exactly the same as what I buy up here in 2CF bags for $3.00 each. Very similar stuff. I agree with Josh about removing some of the sapwood (the long thin white-colored pieces). My bark also has a fair amount of sapwood, and I just pick out what I can when I make the soils. No need to remove every little piece, just remove what you can with your fingers. Your finished soils should be great for your plants.

    Congratulations on your discovery!

    TYG

  • greenman28 NorCal 7b/8a
    9 years ago
    last modified: 9 years ago

    Jeff, sapwood decomposes much faster than bark, which may contribute to the following:
    1) compaction due to decomposition;
    2) Nitrogen binding or immobilization as the wood decomposes;
    3) Heat spikes in the root-zone as the wood decomposes.

    Josh

  • warpiper
    9 years ago
    last modified: 9 years ago

    Hi Josh and TYG,

    Thanks for the tips on picking out the sap wood, I'll removed as much as I can. I'm planning on making mostly 5-1-1 mix for my citrus trees I've been collecting lately and for some figs I want to get. And as of yesterday, I have 2 blueberry bushes (father's day present from my wife) I want to put into bigger pots with the 5-1-1 mix. I'm going to make some 1-1-1 mix for the house plants and may make some for some succulents I want to get. I have everything I need and I was able to make my screening boxes but ran out of time to make the mix. I should be able to make some tonight though.

    Chris

  • neuf
    9 years ago
    last modified: 9 years ago

    Thanks Josh!

    Jeff

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    Chris,

    How did your screening and soil mixing work out? Did you get the results you expected?

    TYG

  • warpiper
    9 years ago
    last modified: 9 years ago

    Hi TYG,

    It didn't. We've been dealing with a family emergency and I haven't been home long enough to play. Things are winding down so I should have time this weekend. I have all the screens made and all the ingredients, so I'm ready to go.

  • warpiper
    9 years ago
    last modified: 9 years ago

    Yea!!! Just made my first batch of 5-1-1!! Of course it started raining so its soaking up some water. I'll make more tomorrow and get my citrus trees re potted. Here are some pictures.

    Here is the pine bark after it was run through a 1/2" screen.

    {{gwi:23199}}

    Here is what was bigger than 1/2" that was screened out. This is what's left after screening a 55 gallon drum of pine bark triple cut.

    {{gwi:23202}}


    And here is my 5-1-1 mix. I forgot to add the lime but I'll do that tomorrow. I'll also add the citustone tomorrow too.

    {{gwi:23204}}

    I'm looking forward to see how my trees like it.

    Chris

  • greenman28 NorCal 7b/8a
    9 years ago
    last modified: 9 years ago

    Looks good! Turn it a few times to get the moisture even, then add a little Lime, turn, add a little Lime, turn, et cetera. After potting the Citrus, put a stake toward the edge of the container (not against the trunk) and tie off to one of the branches. Stabilizing the roots in relation to the mix will encourage faster recovery / root establishment.

    Josh

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    Your 5-1-1 looks really good. Glad you finally found all the necessary materials to make it. I think your plants will enjoy it very much.

    In looking at your photos I noticed that your pine bark has remarkably few large pieces in it. That's a good thing. I usually get at least that many large pieces from a single 2CF bag of bark. The bark you found is probably a much higher quality than what I have available.

    Remember that at first the bark can be slightly hydrophobic. What I do to overcome this is to fill up a black plastic container with your bark mix and soak it in a bucket or tub of water overnight. (Just add enough water to reach the top of the container to avoid the perlite from floating out.) This allows water to completely saturate the mix. After soaking I allow the soil mix to drain for a couple of hours, then I add the plant. After planting you can gently water once more with a hose or watering can just to make sure the soil is settled.

    Have fun and keep us posted.

    TYG

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    WP - what does "I'll also add the citustone tomorrow too" mean?

    When I make 5:1:1. I do it on a tarp spread out on the driveway. I put down 2 or 3 cu ft of bark (depending on the size of the bag it comes in) and wet it with a hose. Not so much that water puddles, but enough to make the bark moist - maybe about a half gallon to 2-3 cu ft. After that, I add the peat over the bark without trying to wet it because it's going to be hydrophobic anyway, + the lime and any other additives I might be using on top of that. Then I add the perlite and wet that. I finish by mixing everything thoroughly with a garden rake with the tines up. If I have help, we can mix everything by lifting alternate sides of the tarp so the mixture rolls over itself as you pull. Within an hr or so, all the water has been absorbed by the soil particles and 'broken' any tendency toward hydrophobia, so the soil absorbs water readily.

    Al

  • warpiper
    9 years ago
    last modified: 9 years ago

    Hi greenman and TYG,

    Thanks for the tips. I only have the metal rod that came with the trees and they are buried into the root ball. I'll get some stakes and stick them in the side and tie off to a branch. That sounds a lot more stable.

    I think I lucked out with the pine bark. The gentleman called it triple cut but the size is right. There was hardly any big pieces. I was surprised with the sphagnum peat moss though. I ran it through the 1/8" screen and got a lot of twigs, roots and a pebble or 2.

    And thank you for the tip on watering the bark. The first batch got rained on all last night and when I compared it to a new batch I made this morning, you can tell the first one had some hydration to it. I'll make sure I soak the next one.

    I potted up a couple of citrus trees earlier this morning and I like how it came out. I moved the trees under the shade of a bigger tree so they won't get too much sun and I'll move them to full sun in a week or so. I want the trees to recover from the re potting.

    Chris

  • warpiper
    9 years ago
    last modified: 9 years ago

    Hi Al,

    Sorry, my bad. It should have read citrus-tone. I forgot to add it and the lime when I mixed up the first batch. And thank you for the details on how you do it. I'll pay more attention to wetting the pine bark on my next batch. The first 2 batches I made, I used a 1 gallon pot as a measure and added 5 of the bark, one peat moss, and one perlite to a 16 gallon plastic tot and mixed it all together.

    I already have the trees in the pots but I can submerse them into a bigger container holding water and let them soak for a few minutes. Would that help hydrate the bark? Thanks.

    Chris

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    Wetting a soil when the peat and bark are both dry presents a challenge. Even if you let water run over a pot for 15 minutes, it often forms channels through the soil and all the soil doesn't get moist. Trying to soak the pot so it gets wet from the bottom up often causes most of the dry soil to float and spill out of the pot. Not to mention how fast fine roots dry out when you pot into a dry soil.

    It's best to pot in a soil that's already moist. If you didn't moisten it when you made it, and the soil is very dry, add about half as much soil as you'll need to a container and add water. Stir until it's soaking wet, then add dry soil and stir again. The result will be a soil you can pot in w/o worry the roots will dry out. The water will diffuse into the dry particles so they are no longer hydrophobic, and you'll be able to water normally a few minutes after the planting is established.

    Do whatever you need to do to avoid potting into a dry soil and trying to fix it after the fact. I wouldn't make such a point of it if I wasn't sure it's a critical consideration.

    Best luck!

    Al

  • warpiper
    9 years ago
    last modified: 9 years ago

    Hi Al,

    Thanks again for your help, I greatly appreciate it. I'll be wetting the bark before mixing and using from now on. I'm new to container gardening and I want to make sure I have the best chance of success that I can. With yours and everyone else's help here, I think I'm off to a good start. :)

    Thanks,

    Chris

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    Keep in mind that container media are all about their structure - how long they can supply a favorable mix of water and air to offer the opportunity for excellent root health. Most prepared soils hold much too much water at container capacity (after being fully saturated and draining has just stopped). Nutrition is not the responsibility of the soil, that's entirely on the grower. Problems start when growers try to bring the garden to the container, losing or lacking focus on soil structure and thinking what works in the garden should work in a pot. More often than not - they don't.

    Also, some growers confuse what is good for them with what is good for the plant. Those are two entirely different perspectives that usually conflict. A high % of disagreements arise when grower A is focused on the well-being of the plant and grower B is focused on how much time/effort it takes to implement something other than the ordinary. Neither perspective is right or wrong - just different.

    Al

  • warpiper
    9 years ago
    last modified: 9 years ago

    I never would have thought about the structure of container soil before, I figured it was just putting dirt into a pot and go from there. That enplanes why I've had trouble with potted plants before (house plants). The plants usually died because of too much water or not enough. Then the soil would harden and never hydrate after that. Your initial post on container soil was great and made sense. My next step is to make some gritty mix and get some house plants. Maybe this time with better luck. :)

    Chris

  • drew51 SE MI Z5b/6a
    9 years ago
    last modified: 9 years ago

    "how long they can supply a favorable mix of water and air to offer the opportunity for excellent root health."

    If you use DE instead of perlite as far as air about 50 thousand years. Doesn't matter much when the structure never breaks down. And it's full of silicon, no need to add any. Works better, is cheaper. and even supplies a needed trace mineral.

    "Nutrition is not the responsibility of the soil, that's entirely on the grower"
    Well if the soil feeds, it always there, I, myself would rather have the soil feed the plant, it's much more efficient, and as stated always there. Not when I think it should be fed.
    As far as soil, and nutrition instead of a one size fits all approach I would rather look at each plant species. This is my approach. For example using 5-1-1 or gritty mix with most carnivorous plants would result in failure. You have to maintain wet feet with them, these are not the best mixes for that, Countless examples like this. Soil structure and nutrition should be decided by what you grow.
    Taste of fruits and vegetables is very much determined by what's in the soil. Such as Vidalia onions have a sweet taste because of local soil makeup. In this case the lack of sulfur. Also true of many vegetables. The same seed tastes a lot different elsewhere.
    Often with humans it is said you are what you eat, same with plants.
    If you like the taste of vegetables in fake soil, with synthetic chemicals, hey go for it!

  • greenman28 NorCal 7b/8a
    9 years ago
    last modified: 9 years ago

    Ah, but we're talking about growing plants in *containers* - not in "soil" in the gardens or fields of Vidalia, or Hatch, New Mexico, et cetera.

    Josh

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    "If you use DE instead of perlite as far as air about 50 thousand years. Doesn't matter much when the structure never breaks down. And it's full of silicon, no need to add any. Works better, is cheaper. and even supplies a needed trace mineral."

    First, your point is moot because root congestion will cause severe limitations before the soil can outlive its useful life - especially the gritty mix. Second, calcined DE contains up to 3/4 of its silica in crystalline form, and amorphous silica is what's beneficial to plants, like the silica in Pro-TeKt 0-0-3.

    While I won't disagree that silicon is beneficial to plant and animal life, it isn't recognized as essential or 'needed' for normal growth, which is why it's an "also beneficial", along with sodium, cobalt, and selenium.

    Depending on the soil to feed your plants is going to create nutritional limitations in the form of unbalanced ratios, nutrients missing or deficient, nutrients unavailable during ebbs in micro-organism populations .... but hey, if you like looking for nutritional problems to solve, by all means - rely on your soil as your sole source of nutrition.

    "For example using 5-1-1 or gritty mix with most carnivorous plants would result in failure."

    ... same thing they told me about AVs, so I bought a couple and grew them in the gritty mix for a year where they thrived.

    You speak with authority about a lot of topics - 'rethinking' mixes w/o ever having tried them, and making absolute conclusions based solely on someone else's opinions. I'd like to see some pictures of all those experiments you so regularly refer to.

    Al

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    Chris - many growers feel that they've just breasted a formidable hump once they understand how important soil structure is to their ability to consistently bring along healthy plant material. Once you get to the point where you can stop fighting your soil for control of your plants' vitality, things become much easier.

    Something to add some perspective on how important root health is to the o/a vitality of the organism:

    Dr Carl Whitcomb, PhD, wrote what is probably the bible on growing plants in containers. Some "Whitcomb-isms":

    "If the root system ain't happy, ain't no part of the plant happy"

    "Roots control the tree, the stems and branches just think [not my emphasis] they are in charge."

    "The more roots to share the load, the faster the dirty work gets done"

    "Roots provide the fuel for the plant engines we call leaves"

    "Each root tip casts a vote to decide what the top will be allowed to do"

    "Top growth gets all the glory, but the roots do all the dirty work"

    He also notes that "Stress can ALWAYS be measured in the root system before symptoms appear in the top [of the plant]".

    Al

  • warpiper
    9 years ago
    last modified: 9 years ago

    Thanks Al. And thanks for the quotes. I'll have to look for some of Dr. Whitcomb's writings. I had to laugh at several of the quotes, they sounded so much like being married! :)

    Chris

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    His book, "Plant Production in Containers II" is an excellent reference that uses easy to understand terminology to guide the serious container grower.

    Al

  • warpiper
    9 years ago
    last modified: 9 years ago

    Cool beans. Thank Al, I'll be looking out for it.

    Chris

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    Al,

    thanks for the tip on Dr. Whitcomb's book. I'll see if I can locate a copy. Should make for some good evening reading this coming winter.

    I have a question for the group about using pine bark and diatomaceous earth as a soil mix. Can I make a good soil mix using only those two materials?

    The reason I ask is that we've had heavy rains here for about a week with cloudbursts every day. I had a small 1 gallon container with a mix of screened pine bark (particles between 1/2" and 1/8") and some coarse grade (1/4" to 3/8") DE sitting outside. I was just testing it to see how much water it would hold during these downpours. Of course when I checked it after a heavy rain I found the media soaked as expected, but I was surprised to find that the container had drained very well and the media retained a nice, loose texture. When I inserted a toothpick in the drainage holes very little, if any, water drained out so no perched water to speak of.

    So perhaps 3 parts screened pine bark and 1 part DE would make a good soil? If so would I still add lime to the soil if using MG 24-8-16 water soluble fertilizer and 1 Tbsp of Osmocote Plus per gallon of soil? Since pine bark has a pH of about 4.5, and DE has a pH of about 7, and it's a 3-1 ratio, then I believe the overall pH of the soil would be about 5 or 5.5 before liming, correct?

    Thanks.

    TYG

  • sharonrossy
    9 years ago
    last modified: 9 years ago

    Ok so I have a question here far less technical but basically this year I used Promix BX to which I added pine bark fines mostly for volume and to help with the structure. I know the promix has lime and micro nutrients, but I added a CRF and a small amount of lime, and I'm using Foliar Pro 9-3-6. My tomatoes are doing fine so far. It just was too hard to make the 5-1-1 both from a physical perspective and also getting pine bark fines was difficult. I obviously made adjustments in quantities added to the mix. So did I do anything I should not have? It drains well and I'm careful about watering and fertilizing with a weak solution.
    Thanks Sharon

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    YG - I don't see any potential issues with what you suggest; and if it doesn't meet your standards, as long as you understand what controls the soil/water relationship. you'll know how to fix it.

    Sharon - if you're happy, we're all happy. ;-) You just took a shortcut to a mix with better aeration and drainage - less perched water, and arrived at the same place most of us are. I'll say the same thing to you as I did to YG - as long as you understand what governs how much air and water a soil holds, you'll have the wherewithal to fix any troubles you encounter in that area - at least you'll have the knowledge. You'll then be taxed with deciding if the effort to fix any problems is worth it to you. To me, what a grower decides to do with the knowledge isn't important, but having the knowledge at his disposal is. That's why if someone tells me he gets great results growing in mud and he's happy doing it, I'm glad for him. If, however, he tells you that you can expect the same results, I'll always disagree and carefully explain why.

    {{gwi:23206}}

  • sharonrossy
    9 years ago
    last modified: 9 years ago

    Thanks Al, I'll keep you posted. I think I have now found a reliable Canadian source for the fines, Alltreat Red Pine bark mulch. I remember being absolutely terrified last year making the 5-1-1 but had good results. Like I said it was a bit overwhelming physically, so yes I did take a shortcut. Time will tell and it's knowledge gained. Thanks for your input.

  • sharonrossy
    9 years ago
    last modified: 9 years ago

    BTW I greatly appreciate all you have done. Most of my friends and family couldn't believe what I am growing the tomatoes in!
    Sharon

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    Al:

    Thanks for your reply. I think I will give this a try.

    I have some DE with a slightly larger particle size than Turface and some nice screened pine bark (all fine material below 1/8" removed) so I'll try an experiment with one of my small trees and see what happens. I'm using 3 parts pine bark to 1 part DE with some CRF and lime added, and fertilize weekly with weak MG 24-8-16.

    My first thought was that without any granite or perlite for drainage this soil mix would stay far too wet. However, 5 days after an initial overnight soaking in a bucket of water followed by several heavy rains the soil mix in the container feels dry on top but only damp below. The mix is not saturated and as far as I can tell is not holding large amounts of water. I think the particle size of both materials is large enough to prevent perched water.

    I'll keep the group posted on how this works.

    Thanks.

    TYG

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    YG - If we were taking a class & had been required as part of an assignment to conceptualize and describe what a perfect soil might be, it would certainly be useful to mention that all or at least almost all of the water retained in the soil proper would be retained inside and/or on the surface of soil particles, rather than in inter-particular air spaces (between the soil particles).

    Thanks for the kind words, Sharon. I get a good measure of satisfaction from the feeling I might have helped you/others get a greater return for their growing efforts.

    Take care, guys!

    Al

  • jodik_gw
    9 years ago
    last modified: 9 years ago

    I don't visit as often as I should... you're welcome for the "bump"! I, too, think this thread should be permanently pasted to the front page of this forum... hopefully we can get that done one of these days. :-)

    Coincidentally, I just finished mixing up some Gritty Mix and getting some of my Hippeastrum bulbs re-potted. I have a lot more re-potting to do, but it sure feels good to work with the medium ingredients, and smell the freshness as I moisten it... it's one of my favorite things to do... work with my plants, and see how healthy they are, and how much they like this medium!

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    Jodi: Yes I agree, working with these mediums is really interesting. Totally different than the bagged mixes.

    Al: Thanks for the advice. Yesterday I mixed up 1 gallon of the pine bark/DE soil and moved a white spruce seedling into the new mix. I added some CRF and watered well. The roots were in excellent shape when the tree was moved over, so we'll see how this experiment goes.

    Thanks.

    TYG

  • hairmetal4ever
    9 years ago
    last modified: 9 years ago

    I have noticed that in my 5-1-1, I do get a SLIGHT PWT (less than an inch) in my non-fabric containers.

    If I decide to run with it and use a wick to get drainage (as opposed to a watering wick), what material do I use, and, how do I do it?

    My thought was to take some rope, tie a knot in it to keep it from falling out of the hole, and stick it in the drainage hole, with enough extra length sticking out to be longer than the height of the PWT...am I on the right track?

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    hairmetal4ever:

    I have not used a wick in a container before so I'm not an expert. However, I recall seeing a photo somewhere in this forum, posted by Al I believe, that shows a wick inside an empty container. Sorry I cannot recall the exact thread where I saw it.

    If I remember the photo correctly it was perhaps a terra cotta container and had a wick it the bottom, very much as you described it. I think it was taped to the bottom of the container via drywall tape or something similar.

    Perhaps another GW forum member can direct you to the photo but from what I remember I think you are on the right track.

    TYG

  • greenman28 NorCal 7b/8a
    9 years ago
    last modified: 9 years ago

    Rayon string or strands from a mop-head are common wicking materials.

    However, the 5-1-1 supports some perched water. It's a more moisture retentive mix. In other words, that's how it's designed. There's no reason to eliminate the moisture.

    Josh

  • jodik_gw
    9 years ago
    last modified: 9 years ago

    I would agree with Josh... for outdoor applications, allowing for a little more moisture to stick around for a tad longer is kind of beneficial.

    We wouldn't want a medium that dried out so quickly and intensely that it became hydrophobic on a daily basis, or that we had to water several times per day to ensure it got enough moisture to its roots... and I think the 511 accomplishes this and is perfect for outdoor container growing.

    As I recall, the piece of mophead string was threaded through a small piece of needlepoint-like screen covering the drainage hole, knotted on the inside of the pot, and allowed to trail out the underside for additional drainage if needed.

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    {{gwi:6819}}
    {{gwi:6822}}

    .... these the pictures we're remembering?

    Al

  • greenman28 NorCal 7b/8a
    9 years ago
    last modified: 9 years ago

    Thanks Jodi and Al ;-)

    Josh

  • the_yard_guy
    9 years ago
    last modified: 9 years ago

    Al:

    Yes those are the photos I was thinking about. thanks for reposting them.

    TYG

  • Vance Evans
    9 years ago
    last modified: 9 years ago

    Hey guys its been a while. Al you have really outdone yourself. Almost 20 threads that is awesome. I'm still trying to work with peace lilies in 5-1-1. I just repotted some that were given to me. At the moment they look terrible and are in shock. I had bare root them and then repot. I wonder if I'm doing something wrong with bare rooting and repotting. Will someone make a video on how to do this? I greatly appreciate it.

    Vance

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    I'd chop 'em all off just above the crown and keep the soil damp, but not wet.

    WHILE you repot, it's important to keep the roots constantly wet. That means you need to be dipping them in a tub of water at least every minute, or removing the old soil with water pressure. The all-important fine roots dry out and die quickly unless you stay on top of keeping them wet.

    AFTER the repot, it's important that you keep the soil moist where it's occupied by the roots, That might mean watering every day until the roots start to colonize the deeper part of the pot. Other than that, you'll need to get a feel for how many fine roots you must leave to support the water needs of the top of the plant.

    I regularly remove up to 90% of a plant's roots during a repot and I almost never ever lose a plant unless it blows out or an animal helps it out of the pot.
    {{gwi:659}}
    {{gwi:661}}


    {{gwi:6332}}
    {{gwi:10873}}
    Al

  • Vance Evans
    9 years ago
    last modified: 9 years ago

    So how many leaves do you normally leave on a peace lily Al? Thanks for the advice I really appreciate it.

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    The number of leaves keeps increasing if you keep the planting healthy. Eventually, you'll need to divide it to keep the o/a manageable.

    Al

  • tapla (mid-Michigan, USDA z5b-6a)
    Original Author
    9 years ago
    last modified: 9 years ago

    Here is a link to the continuation of this thread.

    Thanks to everyone who contributed questions or helpful replies that kept the conversation lively!

    Thanks, Laura, for the heads-up the thread was about to roll over again!

    Al

    Here is a link that might be useful: You can click me too, for a quick trip to the most recent conversations!

    This post was edited by tapla on Fri, Jul 11, 14 at 1:22