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Container Soils - Water Movement and Retention XVII
Container Soils - Water Movement and Retention XVII
I first posted this thread back in March of '05. Sixteen times it has reached the maximum number of posts GW allows to a single thread, which is much more attention than I ever imagined it would garner. I have reposted it in no small part because it has been great fun, and a wonderful catalyst in the forging of new friendships and in increasing my list of acquaintances with similar growing interests. The forum and email exchanges that stem so often from the subject are in themselves enough to make me hope the subject continues to pique interest, and the exchanges provide helpful information. Most of the motivation for posting this thread another time comes from the 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,color>
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 XVI
Post XV
Post XIV
Post XIII
Post XII
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.
This post was edited by tapla on Mon, Jun 10, 13 at 17:06
2402 posts on water retention & movement :) must be pretty important :)
I am pretty sure its about breathing so from where I stand its got to be pretty high up the list , cant breathe cant do much else. sure like to see a few more of those and watch the plants grow great and be able to breathe.
great to see thread 17 off and running.
Woot! In the Houston, TX area, Hapi-Gro brand "Organic Compost"... is perfect pine bark fines, already pH adjusted. Made by Hope Agri products. Under 3 dollars for 2 cubic feet. Available at Lowe's, and many other smaller stores.
I've been using it straight because I'm 1) lazy 2) have too many plants and too many *large* containers. I'm happy to say it's working splendidly. Much better than the high end potting soil I had to buy when I couldn't find a source of pine bark fines.
Hopefully search engines will direct anyone searching for pine bark fines in Houston to this :)
Can you tell that I'm really happy?
Hi Everyone. (not sure if this is the right place to post this) I've got hold of some 2yr old Satsuki Azaleas that I want to repot come spring (i'm in NZ).
I plan to use the 5.1.1 mix. I thinking of using sphagnum moss instead of peat moss simply because I like the idea and the sphagnum here is of prime quality. The other components will be composted pine bark and pumice. Can anyone tell me what the pH will be?
I looked up Turface distributors and I did find one near me in Portland but didn't call yet to see if they are still in business. The thing is that I already bought these round fired clay balls which were not cheap so it would be great if I could use them. One thing I don't understand, is if the Al's Grit mix is fast-draining, does that mean the plant has to be watered daily? There is a lot of material to read. I just foolishly bought a gardenia and now I'm afraid I won't be able to keep it alive. I am scared to wash all the soil off its roots and don't feel much like spending more money on a grit mix just to keep a difficult plant alive that I probably should not have bought. However I did start some little lemon trees from seed so maybe it is something I should learn to do.
I recently checked the pH of my media using the pour-through method. I was interested and concerned because my pawpaws in containers that contained any sand were not doing well (pawpaws like low pH). I discovered that my 5:1:1 mix was close to 5.0 pH, great for my trees, and this was reflected in their good growth. While this conventional 5:1:1 is not exactly what you plan to use, I believe it would have a similar pH. I have been irrigating the mix with acidified water to counteract the high alkalinity of my water. The pH of this acidified water is slightly under 7.0. By the way, my mixes with sand had a pH of 7.0, too high for pawpaws. Apparently, sand around here (SW Ohio) contains a lot of limestone. If I use sand again, I will seek out silica sand.
Good luck.
I am really glad to have come across last year's version of this article. I followed Al's recipe to the letter and tried it out for myself for the first time last year. I also did a few variations. What I discovered was that I needed some tweaks to help with water retention for my vegetable container garden in the Atlanta, GA area.
I appreciate the physics of the well-draining original recipe but I just could not get around to watering enough. But I am working with a greatly improved soil over the "miraculous marketing" soil that I was using when I first found Al's work on this subject, and with more and more use of my own fertilizers and soil components I am getting the costs down as well.
As Al says in the preface to this year's article, you have to figure out what you want and why and understand the physics of it all and then you can find YOUR perfect soil blends for your situations.
I now routinely buy $25 4 cu. ft. bags of Perlite from Pike's Nursery as well as large bags of Sphagnum Peat and 2 cu. ft. bags of American Countryside soil conditioner (made by from Sims Bark Company out of Muscle Shoals, Alabama) from Walmart. This American Countryside brand of soil conditioner is really close to pine bark fines only it has some dirt in it which helps with water retention like I want. Sometimes I add a little Black Kow to get even more water retention and low grade amounts of fertilizer. I'm pretty much using a 1/3, 1/3, 1/3 recipe with ***NO PINE BARK SIFTING*** and this is working out very nicely for me. But it really depends on the kind of plant. If it's a water-sucker like a tomato plant then I might go heavier on the soil conditioner or the Black Kow. If it's less of a water consumer like garlic then I will go lighter on the soil conditioner and Black Kow.
I also use home made compost as well as "worm poop" from my indoor vermiculture farm in place of Black Kow. I'd like to wean myself of Black Kow altogether but I have yet to be able to produce enough of my own stuff. I have a friend with rabbits that is going to give me a bunch of pellets from now on and that may well help me sever my ties to Black Kow next year, we'll see.
I also use controlled release fertilizer. I don't like using liquid fertilizer, although I bought a BUNCH of liquid fertilizer from Kroger this year when they dropped the price by 80% a few weeks ago, so I am stocked up. It's just very time consuming to apply.
Anyhow, thanks, Al, for the continuing education course on why you want a good draining, fluffy soil, how plants and roots work, etc.
I also like that article you once posted about the wooden oak barrel analogy of what plants need -- see link below. It's very helpful to get your mind around all that there is to create the right conditions for your plants and how the "short slat" is going to limit the overall potential.
Here is a link that might be useful: How Plant Growth is Limited (container forum version)
ok, I have taken the dive into the gritty mix. I ended up getting all the ingredients within like a half mile of each other. what I did for pine bark was a bag of pine bark mulch (all I could find) I sifted out the bigger pieces and as much of the sapwood as I could. it seemed to be mostly bark and mostly the correct size, so I was pretty pleased. I then went down the parking lot from the nursery where that was purchased and picked up the manna pro poultry grit 25lb bag at tractor supply, this I didn't sift at all seemed perfect. the smaller bags I noticed seemed to be a finer particle size. then down the street to the napa for my diomite, this is sifted through an insect screen and tried to shake out as much powder as I could.
so 2 cu ft pine mulch 4.99
chicken grit 25 lb 8.99
napa diomite 7.99
not too bad I don't think, most of the mulch seems to be usable. I might look into the stone substitutes to see if its more cost effective the 25lb is not a lot compared to the other ingredients. mostly just posting this to make sure I have not gotten confused in the 1001 posts I've read about this gritty business. im ready to go with this and foliage pro for my houseplants? I've added no lime, I don't need to right? put me at ease! ;) thanks and thanks for everybody who puts all this information on the site, I have learned a lot in a short period of time even with so much more to still wrap my head around.
Hello Al,
Apologies if this has been covered before in one of the earlier threads. How would you (if at all) modify your mixes for seed sowing ? As far as I can see, the main requirement is that seed mixes have smaller particle sizes than potting soils. The commercially-available sowing mixes in my local garden centres are all based on peat, and far too water-retentive for my liking. What would you recommend ?
Thanks for the comments, guys!
Sradley - it seems like you have things covered. Maybe a picture of your soil would be helpful. No lime necessary if you're using the Foliage-Pro.
Fidgety - I usually start seeds in either the gritty mix or the 5:1:1 mix by sowing on top of the mix, then covering the seeds lightly with peat for the 5:1:1 or Turface fines for the gritty mix. The 5:1:1 mix won't need a lot of watering, but the gritty mix should prolly be misted daily - enough to moisten the fines covering the seeds. Seedlings really like the added aeration.
Just wanted to take a moment to thank you for sharing your wealth of knowledge in many areas on this forum. You vast posts of information and experience as well as the advice of others have made me a better grower by far. An invaluable resource.
I killed a f. elastica about 4 years ago when i first tried to get into house/container plants. Very clear why now. I'd say miracle grow potting soil with moisture control was the worst possible thing for the poor little tree. I am itching to try again with proper soil and much improved understanding.
I currently have a number of house plants, but my favorite are my 2 containerized winter gem boxwoods on my balcony! Without you and this forum, they would surely be dead!
I always appreciate someone taking the time to offer a kind word or thank you. Like you, when I started trying to grow things in a container (bonsai), I failed at it because there were too many parts of the growing puzzle missing. Eventually, my studying provided the impetus I needed to start over from scratch. What I try to do is help others avoid to the greatest degree possible the initial frustrations or failures that held me back. Mistakes of bad experiences can be viewed as learning tools, but learning a little in the initial stages can help you sidestep the most common traps. The more intelligent approach of learning to avoid getting bit on the butt by our mistakes and letting our practical application validate what we learned is a whole lot better than charging headlong into unreconnoitered territory w/o anything like a plan.
Best luck. There are a lot of experienced growers here with a very good grasp of what it takes to consistently do well at growing in containers. They really enjoy helping & they're great to be around. There aren't many questions that don't get one or more very good answers, so don't be bashful.
Thanks again.
What a great thread. It was certainly a learning experience. Thanks Al.
If I may ask a question, Is the soil that Al is referring to more so for long term (perrineal) plants. I mean - at the moment I am more focused towards vegetable and herbs container planting. I know it would be better. But considering my situation (in Saudi where many things which Al has mentioned for the mix are not available) can I live on the usual potting mix amending it with something (if so required) as my main focus is short term one season vegetable plantings.
A second question, which I have asked in another thread of mine is about small stones. I read in Al's article that it can be used. I have access to perlite, these small gravel (or stones) and peat moss / vermiculite (and composted cow manure). Can I somehow use this stuff to make an alternate potting mix with similar traits as Al's?
Alternatively, can I use a wick from the drainage holes to drag out Perched Water and keep on using the store bought potting soil? Is it an good alternative?
This post was edited by saood on Wed, Oct 9, 13 at 4:23
First question - not really. Even with short term plantings, you kind of need your properly-made soil from the get-go since you don't get another shot. Of course as I say this, I have annuals marinating in Peat Pudding. They do 'ok' but since seeing the light the last few months on this forum, I'll never plant anything but annuals in the PP again.
Yes, of course you can manufacture a soil concoction and you should definitely experiment! Perlite and peat are two of the three core ingredients for the 5-1-1 so you're almost there. Unfortunately, it doesn't sound like you'll be able to procure the core ingredient of bark fines. Hopefully you will get a lot of suggestions on ratios and improvised formulas on these forums given your available ingredients. In the end tho, there may be a lot of trial and error on your part until you get it right (or close enough), but I'm 100% positive that any new mix you make from the ground up (pun intended) based even loosely on 5-1-1/Gritty principles will be better for your plants than your typical peat-based, store-bought premade mix.
Yes, I think it couldn't hurt to wick that store-bought potting soil. The end goal for all of us though is to get to a point where our pots don't need wicks, i.e. we've discovered the perfect balance between soil porosity and water retention where our plants flourish.
Folks on here use the 5-1-1 mainly for short-term displays, annuals and veggies. They use the Gritty for permanent plantings, trees, perens and houseplants.
Thanks Oxboy. I certainly appreciate your responses very much.
Speaking of experiments, I did a bit of experiment. I filled up a small pot with the peat based soil I have, saturated it to the extent that whatever water could drain out had drained from those holes. The soil inside the pot however was very soggy but not draining. Then I did two things:
1/ I placed a saucer with the same peat based soil in it and placed this pot over that soil (which was quite dry) but no further water drained - the soil inside the pot remained as soggy as it was before.
2/ I placed another saucer with sand in it and placed this pot over that sand and all the soggy-ness was gone in a matter of approx. 10 minutes. The sand wick worked quite well.
After seeing the results, I realized what had I done to my three plants that I was watering every 2-3 days. The pepper plant has almost died because of this. The tomatoes however still are alive and giving up new shoots. Maybe tomato is more tolerant of a water retaining soil.
Frankly, since this is my first go at container gardening (in fact any gardening) my first goal is to first see the results - even though they may be not be so perfect (or even near perfect). See the fruits will actually give me confidence that I can do it and then it be time to target perfection (which can never be achieved though :) )
Thanks once again.
I would use a cloth wick of some kind that dangles down below the pot bottom. This may be hard or impossible to configure if you don't have the pot up on a shelf, rack or bench. You don't want that sandy salty water in the saucer getting sucked back up into the pot. Any chance you can put the pot up on blocks/bricks, which are situated in the saucer? That would get the pot bottom up off any standing water/soggy sand in the saucer and allow you to dangle the wick.
An alternative way to wick that I have used is to place the container that has stopped draining on several pages of newspaper. I have found this more efficient in removing excess water than trying to shove a wick into a drainage hole and then balancing the pot above the wick. I think it would work even better than placing the container on sand. Of course, this will only work if your container has a uniform potting mix from top to bottom (no internal drainage layer), and has holes in the bottom of the pot.
Saood: since you are growing vegetables in containers outside, you should not place a saucer under the container. It is best to allow all the water to drain out of the pot.
Ohiofem: I dont have any saucer beneath the pots. The water drains out on the surface. Thanks for the advise though.
A quick question. I know we need to water untill it drains out so that the salts and minerals that have accumulated can be flushed out. Now if I have a small vegetable plant in a big pot (being the pot size that I select based on its final size), I dont think I need to follow this watering principle. I know the roots are just in the first 2-3 inches of the soil whereas the pot is 12-14 inches deep. So I will water it to the extent that I feel would be sufficient for the top part of the container soil to get moist, I can then gradually keep on increasing the water supply as an when I water to the growing plant. And when I feel the roots have reached somewhere near the bottom of the pot, I can then start watering untill it drains from the bottom. Would this strategy work out? I am thinking that way because I feel a bigger plant can even survive over water but a young plant needs a bit of extra care and this could be a way to care for it without stressing it too much inadvertently (well that is what I have done - overwatering it mainly because of potting soil composition)
Btw, Can we use perlite as the only medium to grow plants. I find a couple of discussion where people have grown successfully in perlite only. (May require a high level of service to the plants)
Does perlite provide some sort of moisture absorption? I understood that it does not. But as I see some discussions and articles on perlite, I find it otherwise.
I also understood that it has no impact on the Ph of the soil but it does have a Ph in the range of 6.8 to 8?
Have I misunderstood?
Here is a link that might be useful: Perlite Chemical and Physical Properties
This is my third consecutive post in this thread. I hope it does not sound like spam :)
Instead of pine bark - which I cannot find - can I use charcoal? It is readily available for BBQ purposes. Is it an alternative?
Any suggestions?
Here is a link that might be useful: Charcoal as potting mix
Charcoal would make a good alternate to perlite, and might be appropriate as a replacement for bark if you're leaning toward something with a large inorganic fraction, like the gritty mix. As always, how it impacts the soil's structure, and therefore its size, are important considerations.
Actually, perlite holds quite a bit of water @ about 3/4 quart per gallon of perlite. It holds the water on its irregular surface, as it is not internally porous. The dry weight of perlite is about 7 lbs/cu ft. Wet, it weighs about 18 lbs for the same volume, so it holds more than 2-1/2 times it's weight in water. This can vary significantly with the size of the particles, with smaller product being able to hold more water on a per volume basis.
Thanks Al for your response. People over here seem to be worried over your absence :)
Actually, my problem is that I have both charcoal and perlite available over here but not the Bark. I was thinking if Charcoal could be used in the 5-1-1 mix in place of Bark. That is 5(Charcoal), 1(Peat), 1(Perlite). Possible?
At the moment on the recommendation of Mike, I have started using Perlite:Ready Potting Mix in 50:50 ratio. Just experiencing if this could work out. Can I use this mix for seed starting?
I just wanted to thank you for being around after all these years for all you have done for me and everyone else..I never forget the day I met you and the difference you have made in my growing experiences...
Thank you:-) Hoping all is well my friend.
Thank you guys so very much for the kind words. When I first started to post, back in '04 or '05, we very rarely talked about drainage or aeration, and there was little written by anyone that fairly indicated how critically important these considerations are to root health, and by extension the o/a well-being of the organism. Today, someone is discussing those issues on one forum or another almost every minute of every day, and drainage/aeration has gone from something that was rarely considered as a possible reason for poor plant performance, to the front of the list of potentialities.
As more and more growers come to understand the importance of a soil's structure, and how the size of the particles the soil is made from factors into that equation, the less I'm needed .... and that's fine with me. I enjoy scanning a forum and seeing someone else schooling those who need help on all the things I've been sharing for years. In many cases, even people I've butted heads with in the past have seen by the overwhelming numbers of successes that the message is anywhere from helpful to critical, depending on the grower's habits and what sort of success the grower is realizing from his/her efforts.
I don't post as much as I used to. Nothing is wrong - no health issues or anything like that ..... I'm just enjoying other things. Also, the amount of email I was getting from GW and another forum site I haven't visited in a long while, was getting unmanageable. I can deal with 10 questions in my mail on a daily basis, but when it gets to be 20 or more, it just takes too much of my time to reply to the emails and try to post at the forums, too. My email isn't quite as full as it was since I started posting less frequently, but I still rarely get fewer than 10 questions each day, and I probably average 5-15 minutes per reply.
Anyway - that's what's up with me. I've made some friends here I think the world of, and taken a lot of satisfaction from knowing my offerings have in many cases made a significant difference in how much a grower gets from the growing experience. I have to admit, that feels GOOD to me. ;-)
Saood - assuming there are no binders or additives in the charcoal, you're probably going to need to crush and screen the charcoal to an appropriate size and try it to determine how well it will work.
In the excitement of reading this thread I forgot to ask my question! Ha...
I'm making the 5-1-1 mix. Could I substitute very small pine bark fines in place of the peat?
When screening the pine bark I had a lot of fines left over, most pieces between 1/8" and fine dust. Id like to use that material in the 5-1-1 if it would be OK to do so.
Here is a link that might be useful:
Thank you for the reply Oxboy. Next time I make some 5-1-1 I will use the extremely small pine bark powder in place of the peat. Glad I can reuse that stuff.
After screening the pine bark with hardware cloth this is what I ended up with as my basic pine bark for the 5-1-1 and grit mix. Hope that looks OK.
I am going to pickup a bag of "allsport" from john deere today! If i understand this correctly, if you get it from john deere, "allsport" is turface MVP. They also carry "allsport pro" which i think has a much smaller particle size.
I will take some pictures as soon as i get it in. :-)
Allsport and AVP are the same thing. The size ranges from large to fine dust.
The Pro-League is what I use for my semi-gritty mix for my dry climate. It has virtually no fines and no large pieces BUT the average size is about 1/12", which is too small to make Al's Gritty where he wants the smallest particles to be 1/10". It is virtually all 1/16" - 1/8" and less than 2% will fall through an insect screen.
I love it for my climate because it doesn't require any sifting and holds more water than AVP screened according to Al's recommendation. NOT what you probably want for a damp climate since it does perch a very small amount of water unlike true gritty mix. I add a wick to my containers to remove that small amount of perched water.
True Gritty Mix held too little water for my Summers in former prime citrus country. On the 10 or so really hot days, my citrus required coming home at lunch to water because morning and night watering was not enough.
Thanks smishgibson, I look forward to seeing your Turface photos! I've read several threads on this forum and members are reporting a significant amount of "waste" (small particles) while screening the Turface, so I will be interested to see how your Turface works out. Can I ask how much your bags of Turface costs?
And thanks to you Greg for letting me know that Turface MVP and Allsport are really the same thing. I was hoping to get that clarification since the John Deere online catalog didnt provide much detail or show any photos of the material.
Good evening all. :)
Just as a follow up, i did not get the turface. I called and they did not receive it in, and they told me it would be Friday instead. I called back and they did not get it Friday.
Its possible they are not going to get it in, so i ended up getting napa oil dry 8822 instead. I think the retailer didn't much want to deal with me. When i ask him about it, he first said, "Ok so you want 1 ton of it?" i said no just a 50 lb bag will do. He said ok so how many 50 lb bags. lol. I said just one i want to try it out first before i order too much of it. He sighed deeply and said OK.
So only time will tell if he actually ordered it or not. Good luck.
smishgibson, thanks for the update. That's too bad the dealer did not want to order that Turface for you. I suspect they are interested in selling materials by the pallet or buy the ton, not two or three 50 LB bags. It's probably not worth it for them to order it in small quantities. I might have the same problem when I go over to my John Deere dealer and ask him/her to order a couple bags of Turface Allsport.
Hi TYG,
I wanted to give you a tip in finding the Turface.
Check with you local sports and rec centers with the people that work on baseball fields. They all use the MVP or All Sport for proper drainage on their fields and they could lead you in the right direction . If you check the web, there is a Turface finder for your area.
Most suggest John Deer distributors, but it seems that isn't working for you.
Any irrigation stores around you?
If you still have issues, I can check for you.. Where do you live?
Hope this helps...
Take care,
Laura, thanks for the post. I've located a source for the NAPA floor dry so i should be ok if the local JD dealer doesn't want to mess with ordering a few bags of Allsport. So the Turface/ floor dry component is all set. I can buy Granigrit or Manna Pro granite too. All i need is a good source of pine bark next spring. We will see what turns up then.
Thanks again Laura.
TYG, John Deere Landscapes finally got the turface in!
Go here to see the thread with detailed info.
Good Luck!
Here is a link that might be useful: Turface Allsport
Al, I've been reading as much as I can about container soils. I've also been asking questions, especially after a couple unfortunate failures in which I jumped in too quickly. I think I understand how the container mixes work in principle. I can't say I have a great "feel" for them yet, especially the gritty mix, but that will take some time.
So thank you for sharing your time and knowledge. I'm hoping to entice some more from you (I know you don't post as frequently these days), if you have time.
1). Why haven't commercial companies picked up on this? I'd have thought that by now companies would be going "oh hey, this idea has been around for at least 10 years and it's only gaining momentum, maybe we should get on it." One of my local nurseries back home had re-packaged Turface they were selling a few months ago. I had just bought a bag, so I didn't look closely. But I would think that kind of thing would be more common these days. Are they hoping it's just a fad?
2). In the last thread (XVI), you talked about how you came up with the two mixes. You mentioned the motivation to use a "mix of a highly water-retentive ingredient + an ingredient that holds no water internally (Turface and granite)". What prompted you to add the bark to it? Why did you settle on those ratios, rather than (for instance) 5-1-1 Turface-bark-granite? You also said somewhere that you use a more coarse version of the mixes than you suggest others use. What is the reason for that?
3). I assume you also considered other materials, especially since discussion opened up on the topic, and some people couldn't find materials, or suggested alternates. But it seems you have stuck by your initial formula. Have you found the initial formula just works better than other variants?
4). Being a fairly systematic guy, I'd love to know how different materials compare. For instance, how do these materials compare in terms of surface area (water held on surface) vs. water or air held internally, and if it factors, how quickly it releases it. Some materials I would wonder about comparison, and what advantages/disadvanges would come with them including, for example:
Diotomaceous earth
Crushed brick (recycled product)
Coarse sand (silica--probably something like 'construction sand')
Scoria/lava rock
Haydite (shale)
Coconut coir (recycled product, substitute for peat)
Cocoa hulls (recycled product, substitute for peat)
Crushed glass (you said somewhere you'd grow a plant on crushed glass on a dare and a bet for something) Not sure if that one's feasible, since it's so smooth
Other options?
("standard" recipe materials included for comparison)
5). When you want to tweak a mix for a particular plant, or environment, how do you figure those adjustments? Is it kind of by feel?
P.s. I'm a little bit of a hippie, I guess, so I'd like to consider recycle products that would otherwise be waste somewhere, if they could work for the purpose.
Unfortunately I can't answer any of your questions, but I've also wondered why soil companies are not selling big bags of the 5-1-1 and gritty mixes. I have seen small bags of bonsai soil at various websites, and some of them are fairly close to the gritty mix, but the bonsai soils are packaged in small bags and quite expensive compared to making your own mixes.
As several people (jodiK comes to mind) have pointed out, selling bagged soil seems to be all about making money, not what is necessarily best for growing plants. My guess is that peat-based soils break down quickly, are not generally reusable from year to year, and are inexpensive for them to make so they have a high profit margin on making and selling peat-based soil. If they made and sold gritty mix, that soil would last for several years and so customers would not have to replace their soil each year, meaning that their annual profits would decline.
That's just my guess why you don't see 2 or 3 CF bags of gritty mix or 5-1-1 for sale.
TURFACE, I think is a brand name(turf +ace), originally used under sports fields to provide drainage and at the same time prevent compaction. In the automotive repair shops they use it to dry up oil spills. There are probably various manufacturers and brand name. Also, there are various grades and particle sizes.
This product is make from DE and fired so that it will not fall apart. Probably cheap ones used in cat litter. In effect it is porous clay.
All you have to do (buying any of those) to make sure that they are fired clay and have a good absorption ration. NAPA has them, O]Reilly has them and landscape supply outfits have them. From what I have gathered the NAPA brand is pretty good.
WHY THEY DON"T SELL 511 potting mix?
I know most of you know the answer. This is just for the benefit of those who don't.
511 is not a widely accepted potting mix. It is sort of a home made recipe, mostly know amongst the members of GW gardening community. Fundamentally it is a pine bark based potting mix ( 70% pine bark, 15% peat moss, 15% perlite). That is why you have to make your own. The hard pat is getting the right kind and size of pine bark. The other two components(peat moss and perlite) are readily available.
I agree with seysonn and others in this thread. If anyone plans to use something other than Turface you should test it to make sure it won't turn to mush. The NAPA #8822 and the OptiSorb are both DE (diotomaceous earth) products and should do well in soil mixes. They are very stable and will not break down when soaked in water.
Most brands of cat litter, as well as other "oil absorbing" products, look similar to Turface but are not acceptable since they usually turn to mushy clay when soaked in water for a few hours. As a general rule, I would avoid buying the cheap bags of cat litter or oil absorbent products for building planting mixes and stick to either Turface, NAPA #8822, or OptiSorb.
Just to clarify, Turface is clay and NAPA 8822 is diatomaceous earth (DE). They are not the same thing. They are both calcined, which means they have been heated to a very high temperature, removing some volatile chemicals and making them very hard. Turface has a slightly lower pH and is a little less absorbent. Both work well in gritty mix. If you find a calcined clay or DE product you want to substitute for one of them, you can test it to see if it will work. Put a cup or more in a small, open container, cover it with water and freeze overnight. Thaw it and see if the particles are still intact and the same size. If they break down when you squeeze them, they will not be suitable for potting mixes.
Also, the use of fir bark in potting mixes was not invented on Gardenweb. I go to a small garden center/nursery that has been in the same family for four generations. The grandson of the original owner tells me they have been growing their trees and shrubs in a pine bark based mix since the beginning. He says that these days, most people prefer peat based mixes for their house plants because that is what they see advertised. In North America, peat is cheap, plentiful and low weight, so it's easier to make packaged mixes that are uniform and less expensive to ship long distances. Some major companies still offer formulas that are predominantly made up of fir bark, like Fafards 52 and Metromix 510.
Hello All. Question regarding screening of pine bark for the 5-1-1 mix.
If I used 1/2" hardware cloth as my only screen when making the 5-1-1 mix, the result would be that all pine bark material 1/2" or smaller, including pine bark dust, would pass through the screen, while everything larger than 1/2" would be discarded and used for other purposes.
Since the screened pine bark would contain a considerable amount of fine, dusty particles would it still be necessary to add the sphagnum peat to the 5-1-1 mix, or would the pine bark fines themselves be a good substitute for the sphagnum peat?
TYG, you have to kind of eyeball it based on how much dust you feel the bark is adding to your mix. Some bags of bark are dustier (fine-ier) than others. IIRC, repto-bark has almost zero dust, so if somebody goes that route, they need to add peat.
I have a feeling you should still add the peat. You can go 5-1-.5 (.5 being the peat) and see how it goes.
Thanks for the reply. The bags of pine bark I've purchased in recent years for my garden beds seem to include a fair amount of small pieces (1/8" to dust).
So if I understand this correctly, if the pine bark has a lot of fine material then I might be able to skip the peat in the 5-1-1 and, essentially make it a 6-1 mix, with six parts of pine bark and 1 part coarse perlite, plus lime. Does that sound right?
I could always add a bit more perlite if the mix has a lot of fines.
oxboy ,,
I agree. Instead of sifting the pine bark, you can reduce the peat moss. You can tell if you can totally skip the PM or lower it. But to find out , you can test screen some pine bark ; say take a gallon of it and screen it and determine exactly how much PM like fines it has.
For the record, the original 5-1-1 mix calls for partially composted bark that is not screened. There will be a lot of particles under 1/16 inch, maybe 10-25 percent. I only eliminate the 1 part peat when there is a lot more of the dust than usual, say more than 25 percent of the bark component.
Not to complicate matters, but one thing that affects me quite often in a new batch of 5-1-1 is that much dust and particulates simply wash out through the drainage holes in the first few weeks. Sometimes my irrigation water is pretty brown/tannic for the first few weeks as I extract it from saucers. Then it clears up as I figure the remaining fine, dusty pieces have "locked in" and caught hold somewhere up in the mix. I'm not saying overcompensate by adding more peat; just saying that it might not hurt if a little more fine stuff is included at creation if you experience the same draining phenomenon as me.
Thanks for the feedback Ohiofem and Oxboy. My takeaway from this is that if the pine bark has a lot of fine material in it then I can either cut back on the peat or eliminate it completely. All depends on how much fine material (1/8" to dust) is in the individual bags of pine bark.
Oxboy, I suppose using of fine plastic screen or fiberglass drywall tape over the drainage holes would keep at least some of the pine bark and peat fines from exiting the container when watering. I'm sure you would still lose some of that material however.
i will add my HUGE praise to al as well!!!
much thanks man..my container plantings have changed
significantly this last yr..and for the better!!!
thanks !! :)
most of my potted plants are tropicals,mostly amorphophallus..and one thing ive needed from the potting mix was good drainage..this yr i used only a 70+% pine bark 30% pumice..when i unpotted my out of pot amorphs..wow..what root systems on those corms!.. i gotta use bigger pots next yr..lol
i did water more often this last summer..but i had no
clogged areas in the pots..which is what i was looking for..
one thing ive learned with the pine bark i get..i dump the bags in huge wheel barrow..fill with water..and let the
tiny particles i dont want in my potting mix settle..the bark of course floats..i just add the sediment remains to compost.. and use the good "powder free remains" in
my potting mix..
i use largest pumice i can find.. still looking for something a bit larger..but.. $$$$ is an issue..i cant find local source..so i have to ship in boxes (last yr..13+) 3 gal boxes.. so im paying $$ for shipping id rather pay for the actual pumice..sigh.. the search continues..:)
Hi All,
I've been reading these posts and the knowledge I'm picking up it phenomenal! Really appreciate the questions that people raise and the responses to it.
I only just got into gardening and took a brave step to repotting my outdoor potted jasmines. Trimmed off the more woody stems that was growing out of the drainage holes and cut away about 1/3 to 1/2 of the roots and the soil was so compacted. I unfortunately am unable to purchase perlite (or haven't searched hard enough) and used a 5:1:1 mix of pine bark, vermiculite and peat moss. I hadn't read this thread before I had repotted this afternoon and I have a feeling I shouldn't have had added in the peat moss because there was some fine dust from the pine bark. Darn it. I hope it grows well though. Prior to this I had been growing the jasmines in a mix of red clay/silt soil and it was doing fantastic so I'm hoping with this repot it'd do much better.
The question I'd like to ask is
A) should I be worried about it being too water retentive? I've been watering the jasmines twice a day using that inferior soil mix and it has lasted me literally years
B) I would like to understand why no one talks much about vermiculite and whether it could substitute perlite?
Many thanks and most appreciated
I can't answer your first question, since I don't have enough experience myself. One newbie to another though, I can say that I've read in a couple topics here that vermiculite holds a bit too much water and breaks down too quickly to be an ideal substitute. It ends up being another water-retaining component, whereas the perlite is supposed to help drainage.
Someone who knows better may be able to give a more detailed answer.
Like Andrew, I'm fairly new here so I cannot answer your first question with any certainty. However, based on what I've read, as long as your 5-1-1 mix has about 1 part of "fine material" I don't think it matters all that much whether the fine material is peat or pine bark fines. If your pine bark has large amounts of fine dusty material then I personally would consider not using the peat. As Ohiofem and others mentioned above, it totally depends on how much fine, dusty material is in your bags of pine bark.
It also depends on how much water you want to retain in the mix. If your plants need large amounts of water, or its very hot in your area, then a bit more of the fine material can be used to retain more water. If you need less water retention, then you can cut back a bit on the fine material used.
One thing you might try, which I will be doing in the spring, is to take a sample of your pine bark from the bag and screen some if it through a 1/8" mesh. If you end up with a lot of material going through the mesh (what I call "pine bark fines", material between 1/8" and dust) then I would consider not using peat in the 5-1-1. However, if you end up with very little material passing through the screen, meaning most of your pine bark is larger than 1/8", then you would probably want to add peat to your mix. Please remember that the amount of fine pine bark material can vary from bag to bag and that near the bottom of the bag you will probably get more fine material than at the top.
Regarding the vermiculite, I did some reading about that in this forum and I believe it's not a good idea to use that, as Andrew mentioned above. I believe it breaks down eventually into soft, squishy pieces of material holding lots of water. So if you use vermiculite your soil will retain more water than you think. That's my understanding, but some of the more veteran members here can give you better guidance on that.
Hi Andrew and the Yard Guy,
I read more posts and I'm with you on vermiculite. I now have no idea what to do with a bag of vermiculite. Could I substitute it for the peat moss in the 5-1-1 mix so that it is 5 parts bark 1 part vermiculite and 1 part perlite?
I checked the soil using a wooden skewer and jammed it all the way down to the bottom and left it there for 30 mins at intervals during the whole day today. It is definitely dryer than all my other plants in other soil types and felt dryer as the day passed without watering. I got paranoid and dug out some of the mix from the middle portion of the pot and it felt more damp than soggy. I'm not entirely sure if I got the mix correct as most of the particles I felt in my hand was bark and some vermiculite so it don't think I have a problem with it getting compacted for a good year until it decomposes.
The jasmines are facing a western sun and get about a good 7 hours of sun. I live in a tropical climate and I'm concerned when it rains heavily.
I'm also wondering if I can repot a plant I just repotted? Prior to potting it I hadn't read about the 5-1-1. Will it hold up? The potted plant seems to like its new soul showing no signs of wilted leaves, droopy leaves or dying yellow leaves - only one or two leaves at the bottom has shed I'm guessing due to natural occurrence and new leaves has grown. I just have a feeling the soil that I potted it to doesn't have enough aeration
Unlike perlite, vermiculite isn't as good choice as part of the base structure of your soil, but can be incorporated if you like, to help you adjust water retention. I have 1-3/4 left of the 2 - 2 gallon bags of vermiculite I bought at least 15 years ago ....... and I make a LOT of soil. That tells you how much/often I use vermiculite. It breaks down structurally quite easily, and compacts. If you want, use it mixed with bark as a substitute for peat.
Damp is good - is what you actually want. Wet, or soggy doesn't make for a medium that facilitates the uptake of water/nutrients.
Why is it you're considering repotting a second time within a short time span?
since i see al here..yea..?? im using pumice in place of
turface..in my mix. i too have a full bag of perlite from 2 yrs ago..i think i'll probably just mix it in my flower beds next yr..just to get rid of it..
??what do ya think of pumice.. i like how its super light,tough..doesnt break down..from this last yr..i didnt have water retention problems in my potted tropicals..
i use about a 3:1 ratio of pine bark to pumice..
much thanks to all !!!!
:) rickster.. do u live in utah??
ya its perlite..
i found 2011 growing season..just over that summer
growing season.the perlite broke down to tiny pieces..
and many of my konjac..they did ok..but the roots were sitting in really damp potting mix..
and..i lost my largest amorph titanum..partly because of
the to wet potting mix..and titanums do pretty good in
continually moist potting mix.. sigh..lesson learned..
so.after reading the many,many very helpful posts here..
especially al !!!! the MAN !! :) i have moved to using my version of 5:1:1 mix..and so far my potted plants have responded very well.. so i plan to keep using this mix..
Lomodor, I live in a very different country so that'll not be doable :)
Mind sharing your version of the 5-1-1 mix? From what I read on the numerous articles on this forum I don't think it quite matters what gravel or substitute you use. The size of it plays the most importance so screening becomes vital to the mix. I'm trying to think of a mix that allows water retention and aeration while it having not to decompose and become compact.
The tropical heat, humidity and rainfall in Malaysia makes it difficult to balance everything. At times it is so hot and needs water retention. At other times it rains torrentially and needs aeration. Although I haven't tried the gritty mix, I don't think it'll work for outdoor potted plants in this climate unless shaded.
From the shops that I've seen selling perlite, most of them are crushed and it costs a lot for something where 1/4 of the perlite can't be used. I'm thinking of using some sort of gravel, bark and peat moss or vermiculite mix.
Al, do you mind explaining why trees in a tropical forest do well even without the gritty mix or human intervention. I'm quite sure the soils in there does not have the same aeration as the mixes you suggest.
I'm not Al, obviously, but much of this I've learned from him.
What happens with water is that it gets literally pulled downward through capillary action: it sticks to particles. If you've ever seen water running along the bottom of a horizontal or angled surface, it is able to do that because of water adhesion. So the soil has a large distance where it can travel downward, adhering to one place, then another, etc. as it travels downward. Along the way, it will fill up air pores that range from very small to quite large. In a pot, there are hard impermeable boundaries where the water can't travel any further. That stops its descent. When enough water gets stopped there, it fills up all those pores along the bottom, and because the water adheres to other water molecules, it fills up all that space along the bottom. This builds up until the pressure from the weight of the water is stronger than the water tension, and it drains out the bottom just enough. But if the soil has enough small particles, the water holds on there, and you end up with a perched water table. In the earth, those water tables are where we often get our fresh drinking water from. In a well-aerated soil mix, the pores are big enough that the water has too much space between particles, so the pull of gravity overpowers the adhesion and cohesion of the water, so excess water drains.
If you stick a wick in the bottom of a pot though, much of that perched water would be drained out. The earth works like that wick, constantly pulling the water downward through capillary action.
I'm not sure I'm explaining this well or getting all the terminology right, but that's the basic principle.
Andrew: Your explanation is good, although it may be a little more complicated than that. The short answer is that growing in a container is very different from growing in the ground. Another factor is that the gritty mix is actually more like the soil in the ground than something like MiracleGro potting mix is. Soil in the ground has a higher proportion of mineral elements (stones, sand and clay, for example) than organic elements (peat, composted leaves and bark).
Also, please note that you do not need to screen anything for the 5-1-1 mix. People often think you do, but Al never said you should.
Lomodor - 3:1 bark to pumice is within reason, but how well it works depends on the size of the bark .... and the pumice.
Rick - If you think you can get your plant through the winter w/o it suffering too much, I'd wait to repot. Keep in mind there are tricks you can employ to help you deal with excess water retention. If, on the other hand, you feel your plant's viability will be in jeopardy before you can repot early next summer, I would bite the bullet & repot now.
Al, do you mind explaining why trees in a tropical forest do well even without the gritty mix or human intervention. I'm quite sure the soils in there does not have the same aeration as the mixes you suggest.
Andrew and Robin gave good answers, so there is little I can add, unless you have other questions.
It's really great to see people who really understand the things I explained in the OP helping others to understand. I'm perfectly happy to remain in the background as long as everyone is getting good, solid advice.
Happy Thanksgiving, everyone!
"Al, do you mind explaining why trees in a tropical forest do well even without the gritty mix or human intervention. I'm quite sure the soils in there does not have the same aeration as the mixes you suggest."
The people above had answered this questions greatly. I too had the same question. Because I was also curious of this, I will add a few things in response.
Remember the forest is an *ecosystem*. A plant in a container is 1 or maybe 2 elements of that ecosystem isolated from the rest. In an ecosystem, you would have the capillary action of the earth, an almost bottomless "container" if you will, pulling the water down. And yes, as the others said, creating a perched water table. However this is very deep in the earth indeed. In our containers, if the soil is bad enough, the perched water table can be half the container, or more!
Also, their are a myriad of plants, using the water in these soils, drying it more quickly that occurs in a container(at least near the surface of the soil where the plants are). A (very) large tree can use 100 gallons a day or more in the summer, with the water transpiring through thousands and thousands of leaves.
We must think of the animals that are part of the ecosystem. Small burrowing animals, insects, etc. Boring an unimaginable number of holes in the soil, aerating it.
I haven't seen any reference to this, but I wonder if bacteria in the soil releasing gas byproducts actually help aerate soils as well?
So when you remove a plant from an ecosystem, and put it in a container, if it is to be grown to its greatest potential, aspects of the "bottomless container, earth" and ecosystem must be mimicked. Little or no perched water, good aeration, and moderately quick dry time(or should i say, less time staying extremely wet).
I like this, Drew. A picture speaks a volume.
The thing is that many plants can thrive in various kinds of media. It is just like soil pH. Most plant can thrive within a wide soil/medium pH range. Some plants LOVE soggy soil, others thrive in arid conditions.
The 511 or Gritty mix are good starting foundations for container planting. So using those formulas as a "One Size Fits All" does not sound rational to ME. Personally, I am going to try/use some version of 511 next season. Maybe I will try 2 or 3 variations to see which one is more suitable to my growing conditions. To me one has to balance moisture retention and drainage issues. In my application , plant life will be 5 months at the most(like peppers, tomatoes, Basil). So this is not the same as house plants.
Someone with excellent horticultural skills will have the knowledge to MAKE almost anything work as a medium, but not all gardeners possess those skills. When you don't, battling a poor medium is baffling and rather unnecessary; and while a good medium doesn't necessarily make a good gardener, it's been shown over and over and over, that it can help those without top notch skills get much greater and more satisfying returns for their efforts. The whole point of going through the effort of producing or acquiring a superior medium is to make it easier for the grower to bring along healthy plant material.
Keep in mind too, that trying to replicate what plants seem to like in situ may be a large mistake, because it's a good bet that it won't work in a container. Additionally, some plants are found only in places that they really don't do as well as they would elsewhere, and might be growing where they are found because they have been outcompeted for space in a more favorable site by one or more species greater vigor. Not everything is as it seems on its face.
Hi Al,
The plant looks fine, one or two leaves have shed but new leaves are forming and growing at the top. I don't see brown tips on the leaves either. It's just that I haven't watered ever since I potted it 3 weeks ago and it seems damp. I left it under shade outside and at time the heavy rain has going to it. It is planted in a self watering container but I haven't filled up the container wth water and this is why I'm afraid. I'm unsure what you mean by waiting until next summer. As far as I know in my country we have sweltering hot sun and drought in January to February and the monsoon in October. All other times are just hot and humid. Does this mean I can repot anytime I want?
My observation of the orange jasmine I repotted the mix feels dry based on the mix in the middle of the pot. I used the 5-1-1 pine bark fines, peat moss and vermiculite and water thoroughly once a day or sometimes once every alternate day. I perhaps need to water twice a day. Prior to this I used the native soils burnt red clay and some cheap black soil and used to water twice a day thoroughly it thrived.
I'll have to send you a picture tomorrow when the sun is up
Thanks so much for your help!
Rick - it's hard to keep everyone straight, insofar as who they are and where they live. You might make it easier on those who converse with you by adding something about where you live to your user info. E.g., my user info indicates I live in Michigan and am sort of in between USDA zones 5b-6a.
If you're close to the equator, less than 25* N or S latitude, you can probably repot any time you wish, but you need to be a little careful about repotting during dry seasons. If using the gritty mix, and if it's made correctly, you should be able to easily repot during the rainy season, but some form of protection might be needed from incessant hard rain.
I'll watch for the pictures.
Rickster: What kind of self watering container are you using? The original 5-1-1 (with perlite instead of vermiculite) is not engineered for wicking water into a container. One of its advantages is that when you water from the top, the water will flush old fertilizer salts out of the mix and draw air in. My understanding is that you need a more absorbent mix for self watering containers.
My understanding of 511 mix is the same as Ohiofem said above.
The main concept about 511 is to have no reservoir of water left in the container between watering. You only try to keep the medium moist all the time. If you want more moisture, need to have more peat moss and vermiculite.
Hi Al,
Sorry I hadn't added that info. I live in Malaysia which is about 2 degrees north of the equator. USDA14 I believe.
Al, would you happen to know about the Eugenia species? I have a 9 feet tree? I've no idea why the leave growth is only occurring on the top. The mid section of the tree seems to be dying. Strange thing is - the tree spurts new growth then it starts to shed all yellow. Take a look at the photo. Potting soil bought in bags from the nurseries. I have a feeling the pot is not big enough and the roots are getting root bound. I remember you saying in some other post on these forums that one of the tell tale signs of root bound plants is leggy branches with dispersed leaves.
Ficus Elastica potting soil and leaves. There is still a spurt of growth and the leaves look healthy. Do you think I need to change the potting mix (mind you I just repotted this) and mist the leaves? I know you've said misting rarely helps but I seethe nurseries doing it all the time.
Orange Jasmine - I just repotted this last weekend using the 5-1-1 mix but used vermiculite instead of perlite. Is this considered too fine a mix? Quite a fair bit of leaves shedding but I kind of expected it when I cut away probably half of its roots. Initially the leaves were looking glum but it looks like it's going to stay alive!
Al, I appreciate the time you take to respond to all our questions. I've been spending more time in the garden of late.
Ohiofem & Seysonn,
I'm using a Lechuza planter http://www.lechuza.us/on/demandware.store/Sites-US-Site/en_US/Home-Show
Yes, I do understand that it needs to have moisture to wick water to the container. I was going to try 10-1-1-1 bark, perlite, vermiculite and peat moss. Not sure if it'll work or whether I should stick to 5-1-1. I believe that the bark, vermiculite and peat moss is able to wick water into the container.
I'm attempting to answer some of my own questions from November 15. It's not totally systematic, and it's not formatted all pretty, but finals are coming up, and I can't afford the time.
Question 1: commercial application, answered by Seyson, Yard_Guy, Ohiofem. Thanks!
Question 2: 1:1:1 mix of bark/turface/granite?
Quote from Al:
"The bark holds water and nutrients. It's water retention is approximately that of the average between Turface and the granite. It's include as filler - it's much less expensive than Turface or granite and lighter. Also, by limiting the bark fraction to 1/3 or less of the medium, the soil will never collapse (structurally) like a peat or bark/peat-based soil would. Your planting will need repotting long before there is even the hint of structural collapse. The small amount of nutrition supplied by the composting process (of the bark) is incidental."
(http://forums2.gardenweb.com/forums/load/houseplt/msg0410560810570.html, April 14, 2012)
So if I'm understanding correctly, in terms of water retention alone, bark=avg. Turface+grit. So in theory we could cut the bark out completely or replace the Turface/grit mixture with straight bark with the same overall water retention. Now the reason we might not follow that train of thought is due to other factors: weight, price, availability, durability, even nutrition/CEC factors (see below). Al, if I'm wrong on this please correct me.
Question 3: Other materials Al has considered for mixes. As mentioned, the concept of the 5-1-1 isn't purely Al's, and it seems from various sources that "it works," so why mess with a good thing. In terms of gritty mix, the same pragmatic approach seems to be the determining factor, if I can put words in Al's mouth. Turface and grit and bark seem to be available where he is for decent price, so why pay more for other materials that won't provide any particular benefit over more readily available materials?
Question 4: Alternative materials. Alternatives seem to be sought out primarily based on lack of local availability at reasonable cost. Sometimes other factors come in, such as slightly increased water retention in DE vs. Turface. Aesthetic or other particular needs may come into play also.
The attached chart image (shrunk on forums) is the result of my reading on comparisons of different materials. Most of the data was already compiled by other people. Hence, it lacks rigorous uniformity of method. Again, consider the comparisons and numbers to be relative, rather than absolute.
Not all materials I suggested as alternatives are considered here. I'll leave that for other people who may be considering alternate substrates. If anyone thinks they can come up with a "more betterer" comparison, I think a number of people would welcome it.
Some sources I used for the chart:
Question 5, and my conclusions based on reading for #4, on alternatives and mixtures:
People will have different needs in different areas. Those considering alternatives have to weigh various factors such as: water retention; aeration; availability; price; weight; aesthetics; etc. In terms of how to figure how much more or less of something to add to a mixture due to specific needs, I think it's going to be a combination of the above factors and a kind of trial-and-error based on accumulated knowledge.
Someone said in another topic, "Gardening is a science." I'm going to make a distinction: I think it's an art, BUT underneath the art, there is a ton of science. A good artist must know the science, just as a carpenter (who is an artisan, in the traditional sense) has to know the science behind how the components work, and it is the application of that knowledge and acquired skill that determines the value of his (or her) artistry.
Thanks everyone for your continuing input and insight. I welcome comments!
If I'm still experiencing leave drop after 11 days of repotting and pruning the root ball is that normal? My potting mix is a 5-1-1 bark, vermiculite and peat moss. I didn't add anything else except water and about 1/4 teaspoon of Epsom salts when I first repotted. Should I be worried? And what should I do?
Are you referring to the Orange Jasmine or one of your other plants? Some plants seem to really resent repotting and root pruning and take a long time to recover. I have killed plants -- a eugenia and an avocado -- by root pruning too aggressively. I also have had plants take more than a month to bounce back after repotting. Keep the plant out of full sun and don't let it dry out completely, but avoid over watering. Don't move it into full sun until it shows signs of recovery.
I do think the combination of a soil mix made with vermiculite, which holds too much water, and a self watering container could be contributing to your problem. The photo of your Orange Jasmine in the modified 5-1-1 looks way too wet to me. I would try to allow the mix to dry out between waterings.
I'm referring to the orange jasmine. I had out it under full sun. Fortunately these couple of days it has been cloudy and raining.
I took more photos of the orange jasmine close up. I'm wondering if it is over watering. As it is my schedule for watering is once every 2 days. I wait under the wooden dowel is dry upon poking it through the soil. I think that photo of the potting mix was a day after thorough watering. The pot is not a self watering one, instead it is a clay pot.
There's some weird yellowing and some leaves look like its burnt or somewhat. The bark looks like it's peeling - although that could be a sign of growth but I have my doubts in this case
Rickster: You probably should take your question about the orange jasmine to the citrus forum. The plant is a relative of citrus and serves as a host for the insects that carry citrus greening disease, which is common in Malaysia from what I read. I suspect your plant is sick and your problem is not caused by your container mix.
Looks good.. But I just checked the website and it is crushed dolomite marble chips... It contains Mg and Ca . Just to let you know... I like the look of it and the price is right.....
Farmers use crushed Granite, Quartzite and Dolomite marble to help aid in the digestion of chickens and other Poultry . They need help with the digestion process and the stones help crush up the food in their stomach and intestines ( aka digestive tract)
Been around the farms for years. ;-)
Hopefully Al will chime In And let you know if this is alright for your plants...
They have a great website and awesome display of products, but then I saw the added minerals listed...
Good luck!!!
This post was edited by loveplants2 on Sun, Dec 8, 13 at 14:17
Thank you so much Al & the other faithfuls who have tirelessly and perhaps unknowingly helped numbskull lurkers like me.
First time poster...newbie gardener trying to soak up as much as I can.
I am still reading this series of Al's thread (I think I'm up to 2011) and wanted to share something that amused, amazed, and cemented the science of PWT in my brain.
I brought in all of my container plants that I bought over spring summer and fall (most were the stressed orphans or out of season clearance plants from Lowes). Most were still in the peat mud they came in.
Anyhow they were doing ok while they were outside but as soon as I brought them in to my new greenhouse within a week or two everything started going downhill. I had already been reading this incredible series so I decided to begin the changeover to Al's mixes by first trying to save the containers with wicks. After I did about half of them I went inside for a couple of hours and when I came back there was quite a ruckus coming from all the dripping wicks. Almost like a light rain. Then it dawned on me that a lot of the plants that I struggled to save over the summer that died of root rot was because of the PWT. I struggled so hard to not overwater or underwater but inevitably I would lose plants. I am so looking forward to not have to worry so much about over-watering once I begin the changeover to Al's mix.
Here's a couple of photos with some wicks I cut up from some sheets of absorbent pads I got from a salvage company 10 years ago. I'm pretty sure they are rayon based on burn test characteristics.
Thanks again Al ! You're amazing!
Thank you for your very interesting post and especially for the photos accompanying it. You have demonstrated one of the important ideas in this long-running thread in a very concrete way and also shown us one creative way to handle wicks.
I also love the photos of the many plant orphans you have saved. You are obviously not a numbskull when it comes to caring for plants if you can keep them looking that good in bad soil. And I am glad you decided to no longer lurk.
Thanks for the kind words, Tony. You'll find a number of folks here who have paid their dues and are always very anxious to help others avoid the problems that are very common but avoidable. I'm also glad you decided to join us and 'go gregarious'. Welcome!
Does anyone have any leads on where I can buy any of the grit that is mentioned in most of the posts here (gran-i-grit, cherrystone, manna pro, purina etc.). I don't live in the US so its more difficult to by online bc they wont/don't ship to Canada. I live in London, Ontario. Im willing to drive 50 k/m or so if I have to in order to get anything.
I've tried TSC, landscaping places, nursery's, garden centres, pet stores and I am pretty sure tried every conceivable google search to find someone who sells poultry grit etc. with NO LUCK.
Living in London (surrounded by farms) you would think there would be tons of places that sells poultry grit/food but I cannot for the life of me find them.
Any info is greatly appreciated. I need to save my citrus as they are seriously declining in their current container mixes.
Hello juventusopp. I am fairly new here but hopefully can help answer your question about sources. Buying supplies can be difficult when starting out.
The grit (granite) for your soil mix should be available at any Tractor Supply (TSC) store. What you are looking for is this:
Manna Pro granite grit is available in both 5lb and 25lb bags at the TSC stores in my area. I'm attaching an image of what it looks like. (Note, the Manna Pro grit is really a gray color, but in my photo it looks purple due to the lighting. It's really gray.)
You mentioned that there are many farms in your area, therefore there must be at least a few farm feed stores nearby. Some of those should have chicken grit, either the Manna Pro or the Gran-I-Grit. At the nearest feed store to me here in Michigan you can buy 5LB bags of Gran-I-Grit or the big 50LB bag. I think the 50LB bag costs about $10 US.
You might also be able to buy Cherrystone up there, and use that in place of granite grit. I have never used the cherrystone but some forum members like it very much. I think it's mined in Minnesota so there might be some stores in your area that carry that. You'll probably just have to call a few of these local places and ask if they have granite or cherrystone.
When you buy your grit make sure that you specify you want "chicken grit" and that you want granite, not oyster shells. The local feed store in my area sells both products for the same purpose but you want granite for your soil mix, and not the oyster shells.
Good luck.
Thanks yard guy.
I'm aware of what I need but just can't find it here. The tractor store in the USA is different than the TSC (formerly one and the same) here in Canada. The fine individuals who make cherrystone don't have a presence in Canada either. I spoke with the Purina people and they don't have a licensing agreement in Canada to sell their grit here. Same goes for Mannapro.
I was able to locate some in Ottawa but it's about 7 hours from where I live and shipping was quoted in and around 50 bucks.
I may just take a trip to port Huron mi. It's about an hour or so away. Just don't know how the customs will be handled. Anywho thanks again. I'll continue to search.
Sorry my post was not very helpful. It sounds as if the usual outlets for grit here in the USA may not apply in Canada. However, Canadian farmers grow chickens and therefore SOMEONE up there must be selling chicken grit to those farmers.
If you can't fine granite grit I suppose one other thing you might try is to locate some fine gravel or large particle sand to take the place of the grit. You might be able to find a suitable alternative at a gravel supplier in your area. Sometimes the home improvement stores have large-grained sand that might work if the particle size is correct.
I have also read that pool filter sand can be used if large enough, although December is not the ideal time to be looking for pool supplies either.
Hope this helps.
Granite (or any so-called grits) have no nutrient value, and have no moisture absorption quality. To me, it is just a filler. I can go to a nursery that sells garden soils, crushed stones, gravel and find something similar. But them you have to do a DOUBLE screening ; One to get rid of big chunks and the second to separates the finer particles.
Finally found some granite poultry grit today. Feed store in Komoka called Hoskin Feed & Country Store. It is actually White Star as well but is not the same as I found above at TSC. Its marked as Granite. Big relief I found this!!
Thanks again all.
That's great news that you found the poultry grit. Very glad you found it.
Interesting to note, I was at my local TSC store yesterday, and they always carry Manna Pro granite chicken grit. However, yesterday they had no granite grit at all, only Manna Pro Oyster Shell grit. The packaging was different than the granite grit. So I'm not sure if something has changed with Manna Pro or with TSC, but I found no granite grit at that particular TSC store.
Seysonn - the granite is used to adjust water retention. E.g., if you change your basic 1:1:1 ratio of bark:turface:grit to 3:4:2, bark:Turface:grit you'll get more water retention (than 1:1:1). Conversely, if you use a ratio of 3:2:4, bark:Turface:grit, you'll have less water retention. W/o the third component, you have no way of reducing water retention except by increasing the organic fraction of the soil to >1/3, which reduces longevity and structural stability.
Hi, guys/gals!! ;-)
Al that sounds great adjusting the ratios, but if the properties of turface are true in the following quote, your adjustment will do nothing, well the increased bark will help.
Hygroscopic water is never available to the plant " it's held to the soil particle too tightly for the plant to use it.
Turface was developed to dry " remove water " from infields. It was not developed to grow plants in. Turface has a very small pore size(Turface has 3 times as much hygroscopic water by weight and 5 times as much by volume than pumice. Water in Turface is significantly less available to plants than water in pumice. (Primary source citation available.)
The author says a citation is available but I have not seen it. If true, that is a huge problem as far as I'm concerned.
Quote is from the Bonsai blog linked in another thread.
Pumice is looking good as a substitute!
You would have to use more pumice, but that is good, it decreases the weight of the mix. If too light you could use lava rock which acts just like pumice, but is heavier. I don't see light weight of any granite mix as an issue though.
I'm curious about the screening sizes too, and where to you find those screens?
Hi Juventusopp!
I received your email this afternoon and I would like to respond, but you don't have it set up to receive messages from GW. I can't send you an email back to answer...
Please send me another email with your return email in the message and I will explain, or I will leave my answer here on the forum if you wish... I will check this thread and my email. ;-)
Take care,
Al. A little bit off topic but while I see you here. I missed your answer (if any) about how you water and feed your small Portulacaria in the acorn shell. I have the same in abalone shells. I remember you said something about a special way to water it but missed out on that thread and cant find it now.
I'm so glad to see this thread still on top of the pile, as it were. It offers so much in the way of sound science and physics, the concepts of which, when applied, offer the grower a chance at truly thriving plants!
I can't thank Al enough for sharing his knowledge and experience... it's helped me to be a much better gardener!
From a posting by tapla in part XV :
"Crushed granite or quartzite, because it is
highly irregular in shape
and has 'sharp' edges
might be a better choice in some apps than perlite"
I am explaining that to myself as follows;
please tell me whether it is what was intended :
Stones in general are better for reason of durability.
Stones' heaviness,
which otherwise would cause them to sink,
is largely offset in the case of granite
by irregularity and sharpness
which make the pieces catch on things.
In the vine transition thread, the question came up: how can one make a medium that will last indefinitely (i.e. no organic matter to rot away, not even slow-rotting pine bark), has good aeration, and has as much water retention and ion exchange capacity as possible within those constraints?
My thought there was as follows: "Maybe something like 0.5% clay could be used, instead of the ... organic matter? Then the question is how to keep the clay from washing out. My thought is to mix in the 0.5% clay suspended just enough water to completely wet the grit [I called it coarse sand there: mineral matter large enough to have negligible perched water], and then let it dry very, very thoroughly. The diminishing water should retreat into the finest crevices where grains are in contact, pulling the clay with it. That should both help keep the clay from washing out, and help clear the larger spaces so air can get through."
Is that plausible?
Fred - there is a small wick that goes through the acorn cap and rests on a wet capillary mat. I only grow these occasionally as companion plants to plants I want to display. The acorn cap rots in a year or so, and the little plant gets tossed. As an alternate to a capillary mat, you could water daily with an eye dropper so you don't blast the soil out of the little cap
Thanks, Jodi. Good to see you here!
Four - I look at the stone in the gritty mix as fulfilling a necessary function. It is the least water-retentive of the 3 basic ingredients, so varying the ratio of grit/stone: Turface, the most water retentive of the 3, you can adjust the water retention of the o/all mix. Perlite regains a lot of water (on it's surface), so for the purpose of adjusting water retention, it would be more difficult using perlite. I'm guessing that a 3:4:2 ratio of bark:grit:Turface (to reduce water retention), you might need to go to something like 3:5:1 bark:grit:Turface to achieve a similar degree of reduction in water retention.
Also, anything irregular in shape, and especially with angular sides, changes the way plants grow by increasing root bifurcation (dividing into 2). A finer root network promotes finer ramification in the top of the plant - more branches and finer foliage - useful for plants where eye appeal is an important consideration.
Keeping materials close to the same size and bulk density helps keep the soil homogeneous. I usually don't have any problems with the 5:1:1, but do often see some migration of the bark fraction of the gritty mix migrating to the top if I water too hard.
Laura - thanks for nominating this thread as a 'sticky'. Jodi has mentioned it from time to time, too. I see GW utilizes the ability to make a thread a sticky, but as yet haven't seen anything by members elevated to 'sticky' status yet. I've never asked on other garden sites that any of my offering be made 'stickies', but I have a lot of posts that are. I'll leave that decision to you guys. Thanks for the kind words.
DSWS - .5% clay is a pretty insignificant number. In most cases, clay would only be desirable in a container medium for its CEC. Because of its very fine size, it's not going to suspend anywhere in a medium, either. It might get trapped in spaces on the surface of some particles, or temporarily in tight spaces between particle's, but by and large it will be washed from the soil in those small amounts.
There are lots of appropriate inorganic materials that can be screened and combined to build a soil with good porosity, water retention, and CEC - some combination of screened Turface and grit being one. You'll need to be thinking in terms of nearly all coarse material (.100-.125" would be ideal) and little fine material in order for it to work as well as it CAN.
> angular sides... increasing root bifurcation.... more branches and finer foliage
Al, thanks for helping on the point of pointy grits.
Of course it arose from the need to find materials.
The prospect of more branches pleases me for the practical reason of
having closer nodes in cuttings.
OK - just posted about a couple commercial mixes (the better ones from what I've read) but may try my hand at making one of Al's mixes.
My intent is to grow tree seedlings that will probably stay in containers through at least next spring - not sure if that is long term or short term...which mix would be best?
Questions - if my CRF is Osmocote Plus (that contains micros) do I still need the gypsum?
Also - what will the pH of this mix be? Most of what I'm growing are going to be Eastern US native trees plus some Asian conifers that will generally thrive in mildly to moderately acidic soils - and our native soils run about 6.0.
Gypsum unnecessary if your fertilizer and/or irrigation water contains sufficient Ca.
Predicting end mix pH depends on too many factors (bark age/quality, amt of peat, water alkalinity, amt of flushing, type of fert, etc etc etc), but if you can get it (and more importantly keep it) around 5.5-5.8, you'll be fine for 90% of container plants out there.
Will you be starting from seed, or potting up liners? just curious. In either case it would be considered a short term thing if you're planting out next spring. Either 5:1:1 or gritty mix will work fine, but if it was me, because it's only 1 growth cycle I'd use the 5:1:1 mix or something very close.
Al -
I'll be starting from seed. I *might* go one extra season depending on the success of some land acquisition I'm working on, FWIW. Thanks!!
OK - few other questions/concerns:
Even using Miracle Gro mix (gasp!) I had plants that needed almost daily watering during sunny 90 degree weather last summer - and last summer wasn't nearly as hot as the one before - I'd be concerned that with these extremely well-drained mixes, I'd have to just leave the hose on a trickle all the time to keep plants moist enough!
I'll be using fabric pots (Smart Pots, etc) - does that change the mechanics of container drainage?
For plants that actually grow naturally in swamps (Bald Cypress for example) is the 5-1-1 or gritty mix still good, or is that a situation where using something with a PWT might be of benefit?
The problem with CRF alone is you never really know when it's all used up until the plant tells you. It may say 9 months on the packaging, but if you live in Vegas like me, that might only be 3 months depending on temps and time of year. I don't like stressing my plants by waiting until visible signs. What if your mom only fed you as a kid when she saw your ribs poking through?
For me lite CRF + lite FP at consistent/regular application rates/times is the 1-2 punch that all but guarantees the nutrients are there when your plant needs them. I like to think of CRF as the pantry and FP as the fridge -- you go to your fridge for quick, accessible, fresh nutrition that only lasts a few days. CRF is the pantry safety net that serves as long-lasting, reliable nutrition source when the fridge is bare.
Replenish the gypsum (if you even need the gypsum) when you replenish the CRF.
I agree with Oxboy. I use both CRF and lime in my 5-1-1 and CRF and gypsum in my gritty mix. Then, I use FoliagePro 9-3-6 or another similar 3:1:2 ratio fertilizer with calcium and micros full-strength starting not long after planting. If you use a soluble fertilizer at reduced strength each time you water, you automatically will be cutting back on fertilization when the plants are dormant or growth has slowed because they need less water then. You don't need to cut fertilizing out completely.
Questions - if my CRF is Osmocote Plus (that contains micros) do I still need the gypsum?
Unless you got Osmocote Plus 15-9-12 before it was discontinued in 2011, the current version doesn't include calcium in it, so you definitely need a source of that. That would be gypsum for the gritty mix or dolomitic lime for the 5-1-1. (You can skip the gypsum for gritty mix if you use a fertilizer that supplies calcium.) I'm planning to use Dynamite All Purpose Select 15-5-9 as a replacement for Osmocote this coming year because it does supply calcium.
If you are going to use 5-1-1, which sounds to me like the better choice in your situation, remember that you definitely need some dolomitic lime in the mix. Not only does it provide a source of calcium and magnesium, it also increases the pH. Bark and sphagnum peat moss both have a very low pH (between 4.0 and 5.0), which is really too low for anything but acid lovers like blueberries.
I say 'never' but I suppose if you watered only with distilled/rain water and used a urea/ammonium based fert, you could be in danger of crashing your 5-1-1 pH below say 5.0. Not a death sentence for blueberries and azaleas, but adding periodic lime would stabilize that situation up closer to the mid 5 pH range that we all kind of shoot for with your typical container plantings.
If you water with hard, high-alkalinity water and don't have the opportunity to flush your pots fairly regularly, do NOT add lime ever after the initial shot. That would likely be a death sentence after a while.
It's pretty important to know. Call up your water provider and hound them for their water quality reports. You at least want an idea of the alkalinity (really important to know IMHO), avg pH and the relative strengths of included micros like calcium, magnesium and sulfur. It's also nice to know the hardness and TDS/salinity.
Failing this, you can at least go buy alkalinity test strips at a pool supply store. Look for 'alkalinity' specifically, not pH or hardness (although those are related and nice to know). It's important to know the concentration of minerals/salts/particles that your irrigation water (read: tap for most of us) natively adds to the potted environment. This in turn tells you how often you need to flush, whether to add vinegar/acid to your irrigation source, whether to change your water source entirely (rain/distilled if that's an option), what type of plants may tolerate your unaltered water chemistry from the tap, etc.
Some may call this nerdy and overboard, but then they wonder why their plants turn yellow and fail after 3 mos. It behooves us to put on the lab coat and learn a little bit about water chemistry, plant nutrition, soil composition etc. Reinforcing this desire to learn is Al's and the other experts' greatest contribution to this forum. I find it fascinating and our plants can only benefit from the more info we absorb and apply....unless of course we end up killing them with kindness, that is... and none of us have ever been guilty of that! wink-wink :)
Maybe I missed it in the thread - but how much mix do you end up with? For the 5-1-1, since particles fall together, having 5 cu yds of bark, 1 cu of peat, 1 cu of perlite won't result in 7 cu, it will be less.
Same question for the gritty mix.
From Baltimore City Water reports (they supply our county water here):
pH averages 7.9 - 8.0
Zinc varies from 0.0005 to 0.013 ppm (2 seperate treatment plants, the water all runs through the same lines)
This data is from a home brewer's forum from 2009, but it's a start. That's an idea, anyway:
Ca 24.2
Mg 6.6
Hardness 91
Alkalinity 53
Sodium 14.5
Chloride 36
Iron Mn 0.01
Al 0.06
Here's a link to the new thread.
Thanks again!
Here is a link that might be useful: Continuation of this thread
If your alkalinity is really 53ppm, you're in great shape. It's the perfect amount between keeping your soil pH stable and avoiding a rapid accumulation of minerals in said soil (which is what can happen if you have 120+ ish ppm like I do). Flush your pots completely every month or so in summer and once or twice between fall and spring if you can. Water so only 20% at most comes out each time so you're not flushing all your fert particles out with each watering.
I would still try to find a more "official" and more recent report from your water district. Or spend the $5 at the pool supply store for the text strips to confirm. I'm kind of OCD and want the peace of mind so that's what I did.