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Tapla's 5-1-1 Container Mix in More Detail

posted by: goodhumusman on 02.26.2009 at 12:44 pm in Container Gardening Forum

I recently joined the forum and discovered Al's 5-1-1 Mix, but I had several questions that Al was kind enough to answer by email. I also found the answers to other questions in several different threads. I thought it would be useful to organize all of the info in one place so that we could have easy access to it. 98% of the following has been cut/pasted from Al's postings, and I apologize in advance if I have somehow misquoted him or taken his ideas out of proper context. The only significant addition from another source is the Cornell method of determining porosity, which I thought would be germane. I have used a question and answer format, using many questions from other members, and I apologize for not giving them proper credit. Thanks to all who contributed to this information. Now, here's Al:

Tapla's 5-1-1 Mix

5 parts pine bark fines
1 part sphagnum peat
1-2 parts perlite
garden lime
controlled release fertilizer (not really necessary)
a micro-nutrient source (seaweed emulsion, Earthjuice, Micro-max, STEM, etc,)

Many friends & forum folk grow in this 5-1-1 mix with very good results. I use it for all my garden display containers. It is intended for annual and vegetable crops in containers. This soil is formulated with a focus on plentiful aeration, which we know has an inverse relationship w/water retention. It takes advantage of particles, the size of which are at or just under the size that would guarantee the soil retains no perched water. (If you have not already read Al's treatise on Water in Container Soils, this would be a good time to do so.) 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 ensure normal water/nutrient uptake and root function.

I grow in highly-aerated soils with the bulk of the particles in the 1/16"-1/8" size, heavily favoring the larger particles, because we know that perched water levels decrease as particle size increases, until finally, as particle size reaches just under 1/8" the perched water table disappears entirely.

Ideal container soils will have a minimum of 60-75% total porosity. This means that when dry, in round numbers, nearly 70% of the total volume of soil is air. The term 'container capacity' is a hort term that describes the saturation level of soils after the soil is saturated and at the point where it has just stopped draining - a fully wetted soil. When soils are at container capacity, they should still have in excess of 30% air porosity. Roughly, a great soil will have about equal parts of solid particles, water, and air when the soil is fully saturated.

This is Cornell's method of determining the various types of porosity:

To ensure sufficient media porosity, it is essential to determine total porosity, aeration porosity, and water-holding porosity. Porosity can be determined through the following procedure:

* With drainage holes sealed in an empty container, fill the container and record the volume of water required to reach the top of the container. This is the container volume.

* Empty and dry the plugged container and fill it with the growing media to the top of the container.

* Irrigate the container medium slowly until it is saturated with water. Several hours may be required to reach the saturation point, which can be recognized by glistening of the medium's surface.

* Record the total volume of water necessary to reach the saturation point as the total pore volume.

* Unplug the drainage holes and allow the water to freely drain from the container media into a pan for several hours.

* Measure the volume of water in the pan after all free water has completed draining. Record this as the aeration pore volume.

* Calculate total porosity, aeration porosity, and water-holding porosity using the following equations (Landis, 1990):

* Total porosity = total pore volume / container volume
* Aeration porosity = aeration pore volume / container volume
* Water-holding porosity = total porosity - aeration porosity

The keys to why I like my 3-1-1 mix:

It's adjustable for water retention.
The ingredients are readily available to me.
It's simple - 3 basic ingredients - equal portions.
It allows nearly 100% control over the nutritional regimen.
It will not collapse - lasts longer than what is prudent between repots.
It is almost totally forgiving of over-watering while retaining good amounts of water between drinks.
It is relatively inexpensive.

Q. Why do you use pine bark fines? 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 natures 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.

Q. What is the correct size of the fines? 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.Pine bark fines are partially composted pine bark. Fines are what are used in mixes because of the small particle size. There will be a naturally occurring "perched water table" (PWT) in containers when soil particulate size is under about .125 (1/8) inch, so best would be particulates in the 1/16 - 3/16 size range with the 1/16-1/8 size range favored.

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 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.

Q. Do you use partially composted pine bark fines? Yes - preferred over fresh fines, which are lighter in color.

Q. I found some Scotchman's Choice Organic Compost, which is made of pine bark fines averaging about 1/8" in size, and, after adding all ingredients, the 5-1-1 Mix had a total porosity of 67% and an aeration porosity of 37%. Is that all right? Yes, that is fine.

Q. What kind of lime do you use? Dolomitic.

Q. What amount of lime should I add if I used 10 gal of pine bark fines and the corresponding amount of the other ingredients? @ 5:1:1, you'll end up with about 12 gallons of soil (the whole is not equal to the sum of the parts when you're talking about soils), so I would use about 10-12 Tbsp or 2/3-3/4 cup of lime.

Q. What grade of coarseness for the lime? Most is sold as garden lime, which is usually prilled powder. Prilling makes it easier to use in drop & broadcast spreaders. The prills dissolve quickly. The finer the powder the quicker the reactive phase is finished. Much of the Ca and Mg will be unavailable until the media pH equalizes so the plant can assimilate the residual elements. Large pieces of lime really extend the duration of the reactive phase.

Q. Does this mean that I need to make up the soil in advance? Yes. 2 weeks or so should be enough time to allow for the reaction phase to be complete & residual Ca/Mg to become more readily available from the outset .

Q. During those 2 weeks, do I need to keep turning it and moistening it? No

Q. Can I go ahead and fill my 3-gal. containers, stack them 3-high, and cover the top one to prevent moisture loss during the waiting period? Something like that would be preferred.

Q. The perlite I use has a large amount of powder even though it is called coarse. Do I need to sift it to get rid of the powder? Not unless it REALLY has a lot - then, the reason wouldn't be because of issues with particle size - it would be because you had to use larger volumes to achieve adequate drainage & larger volumes bring with it the possibility of Fl toxicity for some plants that are fluoride intolerant.

Q. What about earthworm castings (EWC)? I think 10% is a good rule of thumb for the total volume of fine particles. I try to limit peat use to about 10-15% of soil volume & just stay away from those things that rob aeration & promote water retention beyond a minimal perched water table. If you start adding 10% play sand, 10% worm castings, 10% compost, 10% peat, 10% topsoil, 10% vermiculite to a soil, before long you'll be growing in something close to a pudding-like consistency.

Q. Do you drench the mix with fertilized water before putting in containers? No - especially if you incorporate a CRF. It will have lots of fertilizer on it's surface & the soil could already be high in solubles. If you added CRF, wait until you've watered and flushed the soil a couple of times. If you didn't use CRF, you can fertilize with a weak solution the first time you water after the initial planting irrigation.

Q. How much of the micronutrients should I add if I am going to be fertilizing with Foliage Pro 9-3-6, which has all the micronutrients in it? You won't need any additional supplementation as long as you lime.
Q. Just to make sure I understand, are you saying I don't need to use Foliage Pro 9-3-6 until after the initial watering right after planting even if I don't use a CRF? And no additional micronutrients? That's right - on both counts.

Q. Do I need to moisten the peat moss before mixing with the pine bark fines? It helps, yes.

Selections from Notes on Choosing a Fertilizer

A) Plant nutrients are dissolved in water
B) The lower the nutrient concentration, the easier it is for the plant to absorb water and the nutrients dissolved in the water - distilled water is easier for plants to absorb than tap water because there is nothing dissolved in distilled water
C) The higher the nutrient content, the more difficult it is for plants to absorb water and the nutrients dissolved in water
D) To maximize plant vitality, we should supply adequate amounts of all the essential nutrients w/o using concentrations so high that they impede water and nutrient uptake.

All that is in the "Fertilizer Thread" I posted a while back.

Q. Do you use the Dyna-Gro Foliage Pro 9-3-6 exclusively throughout the life of the plant, or change to something else for the flowering/fruiting stage? I use lots of different fertilizers, but if I had to choose only one, it would likely be the FP 9-3-6. It really simplifies things. There are very few plants that won't respond very favorably to this fertilizer. I use fast soils that drain freely & I fertilize at EVERY watering, and it works extremely well.

If you are using a soil that allows you to water freely at every watering, you cannot go wrong by watering weakly weekly, and you can water at 1/8 the recommended dose at every watering if you wish with chemical fertilizers.

Q. What about the "Bloom Booster" fertilizers? To induce more prolific flowering, a reduced N supply will have more and better effect than the high P bloom formulas. When N is reduced, it slows vegetative growth without reducing photosynthesis. Since vegetative growth is limited by a lack of N, and the photosynthetic machinery continues to turn out food, it leaves an expendable surplus for the plant to spend on flowers and fruit. There are no plants I know of that use anywhere near the amount of P as they do N (1/6 is the norm). It makes no sense to me to have more P available than N unless you are targeting a VERY specific growth pattern; and then the P would still be applied in a reasonable ratio to K.

Somewhere along the way, we curiously began to look at fertilizers as miraculous assemblages of growth drugs, and started interpreting the restorative effect (to normal growth) fertilizers have as stimulation beyond what a normal growth rate would be if all nutrients were adequately present in soils. Its no small wonder that we come away with the idea that there are miracle concoctions out there and often end up placing more hope than is reasonable in them.

What I'm pointing out is that fertilizers really should not be looked at as something that will make your plant grow abnormally well - beyond its genetic potential . . . Fertilizers do not/can not stimulate super growth, nor are they designed to. All they can do is correct nutritional deficiencies so plants can grow normally.

Q. Should I use organic ferts or chemical ferts in containers? Organic fertilizers do work to varying degrees in containers, but I would have to say that delivery of the nutrients can be very erratic and unreliable. The reason is that nutrient delivery depends on the organic molecules being broken down in the gut of micro-organisms, and micro-organism populations are boom/bust, varying widely in container culture.

Some of the things affecting the populations are container soil pH, moisture levels, nutrient levels, soil composition, compaction/aeration levels ..... Of particular importance is soil temperatures. When container temperatures rise too high, microbial populations diminish. Temps much under 55* will slow soil biotic activity substantially, reducing or halting delivery of nutrients.

I do include various formulations of fish emulsion in my nutrient program at certain times of the year, but I never rely on them, choosing chemical fertilizers instead. Chemical fertilizers are always immediately available for plant uptake & the results of your applications are much easier to quantify.

Q. Should I feed the plants every time I water? In a word, yes. I want to keep this simple, so Ill just say that the best water absorption occurs when the level of solutes in soil water is lowest, and in the presence of good amounts of oxygen. Our job, because you will not find a sufficient supply of nutrients in a container soil, is to provide a solution of dissolved nutrients that affords the plant a supply in the adequate to luxury range, yet still makes it easy for the plant to take up enough water to be well-hydrated and free of drought stress. All we need to do is supply nutrients in approximately the same ratio as plants use them, and in adequate amounts to keep them in the adequate to luxury range at all times. Remember that we can maximize water uptake by keeping the concentrations of solutes low, so a continual supply of a weak solution is best. Nutrients dont just suddenly appear in large quantities in nature, so the low and continual dose method most closely mimics the nutritional supply Mother Nature offers. If you decide to adopt a "fertilize every time you water" approach, most liquid fertilizers can be applied at to 1 tsp per gallon for best results.

The system is rather self regulating if fertilizer is applied in low concentrations each time you water, even with houseplants in winter. As the plants growth slows, so does its need for both water and nutrients. Larger plants and plants that are growing robustly will need more water and nutrients, so linking nutrient supply to the water supply is a win/win situation all around.

You can tell you've watered too much (or too little - the response is the same - a drought response) when leaves start to turn yellow or you begin to see nutritional deficiencies created by poor root metabolism (usually N and Ca are first evident). You can prevent overwatering by A) testing the soil deep in the container with a wood dowel ... wet & cool - do not water, dry - water. B) feeling the wick & only watering when it's dry C) feel the soil at the drain hole & only water when it feels dry there.

Soils feel dry to our touch when they still have 40-45% moisture content. Plants, however, can still extract water from soils until they dry down to about 25-30%, so there is still around a 15% cush in that plants can still absorb considerable moisture after soils first feel dry to us.

Q. When you water/fertilize, do you give it enough that 10% leaches out the bottom each time? Yes, I try to do that at every watering. Remember that as salts accumulate, both water and nutrient uptake is made more difficult and finally impaired or made impossible in severe cases. Your soils should always allow you to water so that at least 10-15% of the total volume of water applied passes through the soil and out the drain hole to be discarded. This flushes the soil and carries accumulating solutes out the drain hole. In addition, each thorough watering forces stale gases from the soil. CO2 accumulation in heavy soils is very detrimental to root health, but you usually can't apply water in volume enough to force these gases from the soil. Open soils allow free gas exchange at all times.

Q. Should I elevate my pots? The container will not drain the same % of water if it's sitting in a puddle, but the % won't be particularly significant. What will be significant is: if water (in a puddle) is able to make contact with the soil in the container through surface tension and/or capillarity, it will "feed" and prolong the saturated conditions of any PWT that might be in the container. However, if water can soak in or if it will flow away from the containers, there's no advantage to elevating when you're not using a wick.

Q. I like a pH of about 5.7. Is that about right? That's a good number, but you won't have any way of maintaining it in your soil w/o some sophisticated equipment. I never concern myself with media pH. That doesn't mean you should ignore water pH, though. It (water pH) affects the solubility of fertilizers; and generally speaking, the higher the water pH, the lower the degree of nutrient solubility.

Q. How do you repot? Some plants do not take to root-pruning well (palms, eg), but the vast majority of them REALLY appreciate the rejuvenational properties of major root work. I'm not at all delicate in my treatment of rootage when it comes time to repot (completely different from potting-up). Usually I chop or saw the bottom 1/2-2/3 of the root mass off, bare-root the plant, stick it back in the same pot with ALL fresh soil, use a chopstick to move soil into all the spaces/pockets between roots, water/fertilize well & put in the shade for a week to recover. I should mention that this procedure is most effective on plants with woody roots, which most quickly grow to be inefficient as they lignify, thicken, and fill the pot. Those plants with extremely fibrous root systems are easier to care for. For those, I usually saw off the bottom 1/2 - 2/3 of the roots, work a chopstick through the remaining mat of roots, removing a fair amount of soil, prune around the perimeter & repot in fresh, well-aerated soil.

I find that time after time, plants treated in this fashion sulk for a week or two and then put on a huge growth spurt (when repotted in spring or summer). Growth INVARIABLY surpasses what it would have been if the plant was allowed to languish in it's old, root-bound haunts. Potting up is a temporary way to rejuvenate a plant, but if you look ate a long-term graph of plants continually potted-up, you will see continual decline with little spurts of improved vitality at potting-up time. This stress/strain on plants that are potted-up only, eventually takes its toll & plants succumb. There is no reason most houseplants shouldn't live for years and years, yet we often content ourselves with the 'revolving door replacement' of our plants when just a little attention to detail would allow us to call the same plant our friend - often for the rest of our lives if we prefer.

Q. Is there any rule of thumb as to how often to root prune? I'm going to answer as if you included 'repotting' in your question. There is no hard, fast rule here. Some of you grow plants strictly for the blooms, and some plants produce more abundant blooms in containers when they are stressed in some manner. Often, that stress is in the form of keeping them root-bound. I'll talk about maintaining a plant's vitality & let you work out how you want to handle the degree of stress you wish to subject them to, in order to achieve your goals. Before I go on, I'd like to say that I use stress techniques too, to achieve a compact, full plant, and to slow growth of a particularly attractive plant - to KEEP it attractive. ;o) The stress of growing a plant tight can be useful to a degree, but at some point, there will be diminishing returns.

When you need to repot to correct declining vitality:

1) When the soil has collapsed/compacted, or was too water-retentive from the time you last potted-up or repotted. You can identify this condition by soil that remains wet for more than a few days, or by soil that won't take water well. If you water a plant and the soil just sits on top of the soil w/o soaking in, the soil has collapsed/compacted. There is one proviso though: you must be sure that the soil is wet before you assess this condition. Soils often become hydrophobic (water repellent) and difficult to rewet, especially when using liquid organic fertilizers like fish/seaweed emulsions. Make sure this effect is not what you're witnessing by saturating the soil thoroughly & then assessing how fast the water moves downward through the soil. The soils I grow in are extremely fast and water disappears into the mix as soon as it's applied. If it takes more than 30 seconds for a large volume of water to disappear from the surface of the soil, you are almost certainly compromising potential vitality.

I'll talk about the potential vitality for just a sec. Plants will grow best in a damp soil with NO perched water. That is NO saturated layer of water at the bottom of the pot. Roots begin to die a very short time after being subjected to anaerobic conditions. They regenerate again as soon as air returns to the soil. This cyclic death/regeneration of roots steals valuable energy from the plant that might well have been employed to increase o/a biomass, and/or produce flowers and fruit. This is the loss of potential vitality I refer to.

2) When the plant is growing under tight conditions and has stopped extending, it is under strain, which will eventually lead to its death. "Plants must grow to live. Any plant that is not growing is dying." Dr. Alex Shigo Unless there are nutritional issues, plants that have stopped extending and show no growth when they should be coming into a period of robust growth usually need repotting. You can usually confirm your suspicions/diagnosis by looking for rootage "crawling" over the soil surface and/or growing out of the drain hole, or by lifting the plant from its pot & examining the root mass for encircling roots - especially fat roots at the container's edge. You'll be much less apt to find these types of roots encircling inner container perimeter in well-aerated soils because the roots find the entire soil mass hospitable. Roots are opportunistic and will be found in great abundance at the outside edge of the soil mass in plantings with poor drainage & soggy soil conditions - they're there looking for air.

3) When the soil is so compacted & water retentive that you must water in sips and cannot fully flush the soil at each watering for fear of creating conditions that will cause root rot. This isn't to say you MUST flush the soil at every watering, but the soil should drain well enough to ALLOW you to water this way whenever you prefer. This type of soil offers you the most protection against over-watering and you would really have to work hard at over-fertilizing in this type of soil. It will allow you to fertilize with a weak solution at every watering - even in winter if you prefer.

Incidentally, I reject the frequent anecdotal evidence that keeping N in soils at adequacy levels throughout the winter "forces" growth or "forces weak growth". Plants take what they need and leave the rest. While there could easily be the toxicity issues associated with too much fertilizer in soils due to a combination of inappropriate watering practices, inappropriate fertilizing practices, and an inappropriate soil, it's neither N toxicity NOR the presence of adequate N in soils that causes weak growth, it's low light levels.

Q. Is there any rule of thumb as to how often to remove and replace the old soil? Yes - every time you repot.

As always, I hope that those who read what I say about soils will ultimately take with them the idea that the soil is the foundation of every container planting & has effects that reach far beyond the obvious, but there is a snatch of lyrics from an old 70's song that might be appropriate: "... just take what you need and leave the rest ..." ;o)

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clipped on: 09.27.2009 at 12:27 pm    last updated on: 09.27.2009 at 12:27 pm

RE: Hey, Tomcath.... (Follow-Up #25)

posted by: tomncath on 01.31.2009 at 07:36 am in Florida Gardening Forum

Only one deterrent I've though of that I have not experienced yet, what happens with three hours or three days of rain? My little bunkers will be flooded with three days of rain, during the summer the inside containers can be elevated some to protect from three hours of rain, but the reality is that the bunkers will flood occasionally...could be problematic.

Tom

Updated information, I had to double-pot the bunker pots for structural wall integrity as my nursery pots are so flimsy that the sides were caving in some. In retrospect, I think it was beneficial in two ways. First, there is airspace between the two bunker pots so how could nematodes possibly get into my container soils? Second, when the spring and summer rains do come they will flood the airspace chamber first...the inner bunker pot actually elevates the soil container some and may diminish the potential for soil flooding.

Tom

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clipped on: 08.24.2009 at 07:20 am    last updated on: 08.24.2009 at 07:20 am

RE: Hey, Tomcath.... (Follow-Up #21)

posted by: tomncath on 01.23.2009 at 06:22 am in Florida Gardening Forum

Tom any suggestions on other sources for getting the perlite or peat at lower prices.And tom do you mix your CRF in with the entire potting mix or do you spread it on the top layer?

Hi Kirk,

They don't all carry it so you'll have to look but some HD's have the 4CF bags of COARSE perlite. If your local HD doesn't have it go to the Service Desk and ask them to have one shipped in for you, should be about $13. Otherwise, find a Paint Store and see if they have it in the 4CF bag, it's used as the "popcorn" in popcorn ceilings.

The peat at HD is very expensive. Get a 3.8CF compressed bale at your local ACE Hardware ($12), and when you go to mix your stuff up prep the compressed peat first as it will need quite a bit of wetting and volume expansion, then add the bark and perlite after you've prepped the peat.

Currently I use Florikam Nurticoat Total 13-13-13 and do put it in the mix. It's a 180 day release but will take a few weeks to kick in so I supplement weekly during weeks #2-4 with Foliage Pro 9-3-6. You can get the Nutricoat at Cypress Creek in Tampa but you may have to call them and have a bag shipped in as they usually only order 1-2 bags at a time...this is the same product as Dynamite, just $1.50/lb instead of $5/lb since it's in a 50lb bag.

Tom

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clipped on: 08.24.2009 at 07:19 am    last updated on: 08.24.2009 at 07:19 am

RE: Hey, Tomcath.... (Follow-Up #14)

posted by: tomncath on 01.14.2009 at 06:38 am in Florida Gardening Forum

Tom, yea I would like that---"...I'll shoot some topographic pictures this weekend if you'd like"
Are you drip irrigating?

Bernie, I'll shoot some pictures this weekend. I'm hand watering so I can inspect the soil since this is my first season in Al's mix. As it cools down I'm finding I can back off to watering every other day to every third day.

annafl did you find your pinebark fines at walmart also? Il be trying to find some place in my area that has them soon...think il be able to use this pinebark mix for more than one season by just adding more perlite and peat,im sure it wont be as good as the 1st years mix but should still grow some decent plants.

Kirk, you're in Dade City right? If you get down to Tampa you can get 2CF bags of Pine Fines or Pine mini-nuggets at Treemart on N. Nebraska Ave. Or, if you have a pickup truck and want to buy a cubic yard Cypress Creek on N. Florida, and Mulch Express on N. Nebraska both sell it by the yard for $22, it's light enough that I get a yard in the back of my Ford Ranger with no problems.

From what I've read most folks use the mix for two years, then use it as a bedding supplement.

...I have a question about the dolomitic lime. I know it is good for tomatoes to prevent blossom end rot, but Al uses it in his mix for everything? Is it because the pine bark fines are acidic? I'm just wondering if I use the mix for ornamentals or fruit trees, do I put the lime in as well?

Anna, one of the primary nutrients plants need, just like us for strong bones, is calcium. Thus, it's a vital component of all good potting mixes....

Tom

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clipped on: 08.24.2009 at 07:18 am    last updated on: 08.24.2009 at 07:18 am

Container Soils - Water Movement & Retention V

posted by: tapla on 04.09.2008 at 08:08 pm in Container Gardening Forum

A thread similar to this has been posted four other times. Each of the other postings have reached the maximum allowable - 150 replies. I would like to preface this post by saying that over the last few years, the thread & subject has garnered a fair amount of attention, evidenced by the many, many e-mails I find in my in-box, and has been a wonderful catalyst in the forging of new friendships and in increasing my list of acquaintances with similar growing interests. I welcome these individual exchanges, which alone are enough to make me hope the subject continues to pique interest and curiosity. Not an afterthought - I should add that there is equal satisfaction in the knowledge that some of the information provided in good-spirited exchange might be making a significant difference in some growers' success or satisfaction.
I'll provide links to the previous three threads at the end of what I have written. Thank you for looking into this subject - I hope that any/all who read it take something interesting and helpful from it. I know it's long, but I hope you find it worth the read.

Al

Container Soils - Water Movement and Retention

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. Soil is the foundation that all container plantings are built on, and aeration is the cornerstone of that foundation. Since aeration and drainage are inversely linked to soil particle size, it makes good sense to try to find and use soils or primary components with particles larger than peat. That components retain their structure for extended periods is also extremely important. Pine and some other types of conifer bark fit the bill nicely and Ill talk more about them later.

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

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

Consider this if you will:

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

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

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

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

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

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

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

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

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

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

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

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

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

My Basic Soil

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

5 parts pine bark fines
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime (or gypsum in some cases)
controlled release fertilizer (if preferred)
micronutrient powder, other continued source of micronutrients, or fertilizer with all 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 micronutrient powder (or other source of the minors)

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
micro-nutrient powder (or other source of the minors)

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

Thank you for your interest.

Al Fassezke

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

Posting I

Posting II

Posting III

Posting IV



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clipped on: 08.24.2009 at 07:17 am    last updated on: 08.24.2009 at 07:17 am

RE: Hey, Tomcath.... (Follow-Up #10)

posted by: tomncath on 01.13.2009 at 07:31 pm in Florida Gardening Forum

Bernie - Arkansas Boy says "come on down", I'll send you an email shortly.

Doesn't matter if the inner pots shift a little, even up against the sides of the outer pots...haven't had it happen so far though because everything I'm growing vertically is either caged or trellised...I'll shoot some topographic pictures this weekend if you'd like.

SWC - self watering containers, the Earth Box folks are getting rather testy about use of their trademark name so this term loosely covers all the homemade bottom watering reservoir concepts....

Bill - I'm sure you won't have soil temp problems with that volume of soil. BTW, I have to thank you for opening my eyes to the fact that "less is more", by giving my maters much more space I honestly think the production went up 25% and the transfer of disease down by the same amount! :-)

Anna - that's great! If you're going to follow this concept I really think you should seriously consider using Al's mix, have you studied it?

All my nursery containers are flimsy except the 10 gallon ones. The space between the 10/7s is only 2.5", between the 7/5s is 1.5"...can't fall over and the trellis or cage keeps the plants from shifting too much...so far so good. Only one deterrent I've though of that I have not experienced yet, what happens with three hours or three days of rain? My little bunkers will be flooded with three days of rain, during the summer the inside containers can be elevated some to protect from three hours of rain, but the reality is that the bunkers will flood occasionally...could be problematic.

Tom

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clipped on: 08.24.2009 at 07:17 am    last updated on: 08.24.2009 at 07:17 am

RE: Hey, Tomcath.... (Follow-Up #1)

posted by: tomncath on 01.12.2009 at 07:25 pm in Florida Gardening Forum

Hi Anna,

Like I said in your other post, I'd sacrifice one of the containers if covered, pull the cover and eyeball and feel the soil from top to bottom, you have nothing to lose...may just need to mix a drier soil. I think lots of folks are very successful with SWCs and I'll be toying with the concept myself in an attempt to reduce water waste.

Having said that if I'm unsuccessful with SCWs I'll resume my current practice, but here's what I currently do:

- I grow everything in plan old black nursery containers (You can get nursery containers reasonably priced locally if you're willing to buy in bulk....)

- I grow the indeterminates in 7 gallon containers

- I grow Cherries, determinates, squash, cukes, zukes, okra, pole beans and most everything else in 5 gallon containers (exception peppers go in three gallon containers)

- I sunk 10 gallon containers in the ground to put the 7 gallon containers in

- I sunk 7 gallon containers in the ground to put the 5 gallon containers in

- I laid a bed of oak tree leaves in the bottom of the "bunkered" containers to discourage nematodes since they don't like highly organic debris

- Nothing between the inner and outer pots, just an air layer to promote good oxygenation and gas exchange. The real purpose of sinking the pots is just to get them below ground level to keep the soil cooler during the spring and summer

- I use Al's mix, 70% pine fines, 15% perlite and 15% peat to promote good drainage and oxygenation/gas exchange...plus Nurticote CRF, and dolomite for a calcium source. Since the Nutricote I'm using is a 180 day product and takes 2-3 weeks to kick in I supplement weekly weakly with Foliage Pro 3-1-2 during weeks #2-4. When in doubt, better to put less fertilizer in your potting mix than too much, you can always supplement with a liquid fertilizer if warranted.

I'm sure something is missing so fire away with questions ;-)

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clipped on: 08.24.2009 at 07:15 am    last updated on: 08.24.2009 at 07:15 am

Forgot how to add pics here (Follow-Up #16)

posted by: tclynx on 01.31.2009 at 09:25 am in Florida Gardening Forum

Sorry about that I had to re-teach myself how to post pictures.

shade structure

shade structure

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clipped on: 08.24.2009 at 07:13 am    last updated on: 08.24.2009 at 07:13 am

RE: Tom's in-ground pot-in-pot model for growing veggies (Follow-Up #12)

posted by: tomncath on 01.30.2009 at 07:46 pm in Florida Gardening Forum

Hi folks, I've been writing a long version of this setup but felt it was taking too long to finish so I though I'd post some pictures in the interim.

Trini - It's Cattle Panel and 8' T-posts

Willy - Thanks, always nice to see pictures of your amazing garden too!

Ill-man - I take bolt cutters and cut the entire 16' length of CP just below the third section (3 x 6" = 18"). I then lay the 16' x 18" section on the driveway, place a 2' long 4x4 horizontally just after the #10 sections, put my weight on the 4x4 and pull up on one side to about 70 degrees, then get up and use my feet to finish bending to 90 degrees. Repeat on other side. Cut horizontal ends off so you have prongs on each end to stick in the ground for stabilization and you end up with a cage that is 72" tall (9 x 8"), 32" wide (4 x 8") and 18" deep (3 x 6").

Bernie - Guess I'd better get to work finishing the long post ;-)

Olya - I LOVE your flowers, and you're no slouch when it comes to veggies either!

Anna - Give your indeterminates some space, at least FOUR feet, that's something I've learned from Bill.

Jeff - Nice to see you're using buckets this way too, gives the folks here more options.... I've been giving lots of veggies to the deli folks at my SweetBay and in turn they've been saving me the 2, 4, and 5 gallon icing buckets. I'm planning on trying SWCs in some of my bunkers to see if I can reduce the water waste. If successful I may move that way to be more efficient, only time will tell.

Mel - I'm not an engineer, I'm in the medical field and currently working fifty hours a week...let's play What's my Line, OOPS, just gave my age away ;-) Bravo on figuring out how I made the tomato cages, just used a 4x4 instead of PVC so I could put my weight on the 4x4 to keep it from moving.

Well draining soil, cooler soil temperatures than traditional container gardening and lack of pest all equal better production and less work....

Lisa - Nice to see another cracker ;-)

Liz - I'll finish my semi-journal version this weekend and post it by Sunday night...gonna be too cold to plant the stuff I wanted to this weekend anyway :-(

Everybody stay WARM this weekend!

Tom

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clipped on: 08.24.2009 at 07:12 am    last updated on: 08.24.2009 at 07:12 am

Tom's in-ground pot-in-pot model for growing veggies

posted by: tomncath on 01.29.2009 at 05:17 pm in Florida Gardening Forum

So, last year after being frustrated with nematode problems I covered my raised beds with cypress mulch and moved into nursery containers set above the cypress mulch. I had significantly improved success over my diseased soil but noted that the container potting mixes were hotter than optimal. I though about using the post-hole method but didn't really want to be digging new postholes every season so I decided to stay with the containers but use an in-ground pot-in-pot model like some of the professional nurseries do. Hopefully, this will overcome the summer heat and keep my potting mixes cooler. Also, to discourage nematodes from migrating through the bottom holes in the larger containers I spread a layer of oak leaves at the bottom of the containers since nematodes don't like organic material much...so far it's worked.

I'm posting these pictures since several folks have requested better pictures of the setup.

Photobucket
Early fall picture

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Early fall picture

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Late fall picture, cukes are history!

Photobucket
I just set this cut-back Baby Bubba okra in the 10 gallon bunker for perspective, 7 gallon container, 10 gallon bunker, used for indeterminate tomatoes.

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Beefmaster tomato, 7 gallon container, 10 gallon bunker.

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Just started super sugar snap peas after pulling out the cukes. 5 gallon containers, 7 gallon bunkers.

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The row of sugar snaps....

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Just set this Indian Stripe after pulling out a Jetsetter. Yes, I successfully grew large indeterminate's in 5 gallon containers.... 5 gallon container, 7 gallon bunker.

Photobucket
I used the smaller containers in the narrow beds on the north side of the boardwalk.

I hope these pictures answer your questions, if not drop me a line.

Tom

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clipped on: 08.24.2009 at 07:08 am    last updated on: 08.24.2009 at 07:08 am

RE: Can tomatoes be grown in Floridas heat? (Follow-Up #46)

posted by: tomncath on 07.06.2008 at 07:11 pm in Florida Gardening Forum

Update, a week later and my maters are looking ratty so I picked everything fairly mature, and obviously we'll be having some fried green maters. Granted I didn't spray with BT and the bugs and heat are definitely taking their toll but I have to state that these matters taste GREAT! I'm so encouraged by these heat tolerant strains that I started six Sunmaster seeds today, planning to set them 9/1 just to see what happens, hopefully they won't drown. I hope everyone have a safe and enjoyable 4th...back to work tomorrow, bummer, I'd rather play in the garden!

07-06 Maters

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clipped on: 08.24.2009 at 07:06 am    last updated on: 08.24.2009 at 07:06 am

RE: Can tomatoes be grown in Floridas heat? (Follow-Up #23)

posted by: tomncath on 06.29.2008 at 08:24 am in Florida Gardening Forum

Well, my second mater from this summer experiment was actually much better tasting that the first one. The Solar Set is clearly setting fruit better than the Solar Fire. I have them double-potted (7gal in 10gal) to keep the soil heat down and as you can see they are up under the canopy of a live oak tree so they are only getting six hours of direct sunlight. I didn't give them any CRF and I have not been the best at hitting them with MG, and I didn't cage them because I really didn't expect them to do as well as they have so far....

Summer Maters

Summer Maters 06-29

Solar Set

Slim Pickins!

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clipped on: 08.24.2009 at 07:04 am    last updated on: 08.24.2009 at 07:04 am

Science vs ignorant beliefs

posted by: tampaart on 04.06.2009 at 04:16 pm in Florida Gardening Forum

As a native Floridian who has grown "things" his entire life (50+ years) I've heard some zingers about what does and doesn't work in our state.

Call it wives tales or just plan northern ignorance of Florida gardening I'd like to hear some of your "zingers".

Example: If I pour the old pickle juice on my gardenia plant it will bloom profusely.

Thanks,
Steve
Davis Islands

My backyard


Photobucket

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clipped on: 04.07.2009 at 10:18 am    last updated on: 04.07.2009 at 10:18 am

Loggerhead Sea Turtle WIP

posted by: mermaid4life on 06.30.2008 at 02:09 pm in Stained Glass & Mosaics Forum

Have been planning to do this for a long time. This will go in our new pool bathroom which has 3 shades of Illiminati tiles in paradise, st kitts and a combination.

This is very early playing and i find if i take a pix and look back on the item i am mosaicing, , it really helps me "see" what others are seeiing.

I do see i need to rearrange all of these tiles LOL! and take many off and then look for an irridescent brownish beigh to make her really pop.

any ideas??Loggerhead sea turtle

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clipped on: 07.09.2008 at 10:14 pm    last updated on: 07.09.2008 at 10:14 pm

Lightstreams glass tile

posted by: hargyle on 01.20.2008 at 11:49 am in Pools & Spas Forum

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Photobuckethref="http://s235.photobucket.com/albums/ee262/haargyle/?action=view&current=Pooltwo1207014.jpg" target="_blank">Photobucket

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clipped on: 01.21.2008 at 01:38 pm    last updated on: 01.21.2008 at 01:38 pm

RE: Variegated Heliconia in bloom (Follow-Up #9)

posted by: gcmastiffs on 01.16.2008 at 01:33 pm in Florida Gardening Forum

Here is a flower. But the foliage is the main attraction.

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Lisa

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clipped on: 01.16.2008 at 08:50 pm    last updated on: 01.16.2008 at 08:50 pm

Variegated Heliconias

posted by: gcmastiffs on 01.16.2008 at 10:53 am in Florida Gardening Forum

I was puttering around on EBay this morning, and found that the variegated Heliconia "El Tigre" that Katkin so kindly separated for me at Treefrog's party, is selling for $110! For a single stalk!

Hope all the offspring of my original $30 plant are doing well for those who got them! Please let me know. Mine are doing great and recently flowered.

Man, I wonder how much the Bihai Lamaii Variegata is worth these days? Can't find it available online anywhere, and mine is busting out of its pot.

Oh Katkin, I need your skilled hands again(G). Got a sharp machete?

Lisa

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clipped on: 01.16.2008 at 08:49 pm    last updated on: 01.16.2008 at 08:50 pm