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Container Soils - Water Movement and Retention XI
I first posted this thread back in March of 05. Ten times previous, it has reached the maximum number of posts GW allows to a single thread (150), 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 again comes from the participants reinforcement of the idea that some of the information provided in good-spirited collective exchange will make some degree of difference in the level of satisfaction of many readers growing experience.
I'll provide links to some of the previous nine threads and nearly 1,700 posts at the end of what I have written - in case you have interest in reviewing them. Thank you for taking the time to look into this subject - I hope that any/all who read it take at least something interesting and helpful from it. I know it's long; my wish is that you find it worth the read.
Container Soils - Water Movement and Retentionsize>
A Discussion About Soilssize>color>
As container gardeners, our first priority should be to insure the soils we use are adequately aerated for the life of the planting, or in the case of perennial material (trees, shrubs, garden perennials), from repot to repot. Soil aeration/drainage is the most important consideration in any container planting. Soils are the foundation that all container plantings are built on, and aeration is the very cornerstone of that foundation. Since aeration and drainage are inversely linked to soil particle size, it makes good sense to try to find and use soils or primary components with particles larger than peat. 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 IÂll talk more about various components later.
What I will write also hits pretty hard against the futility in using a drainage layer of coarse materials as an attempt to improve drainage. It just doesn't work. All it does is reduce the total volume of soil available for root colonization. A wick can be employed to remove water from the saturated layer of soil at the container bottom, but a drainage layer is not effective. A wick can be made to work in reverse of the self-watering pots widely being discussed on this forum now.
Since there are many questions about soils appropriate for use in containers, I'll post basic mix recipes later, in case any would like to try the soil. It will follow the Water Movement information.
Consider this if you will:
Soil fills only a few needs in container culture. Among them are: Anchorage - A place for roots to extend, securing the plant and preventing it from toppling. Nutrient Retention - It must retain enough nutrients in available form to sustain plant systems. Gas Exchange - It must be sufficiently porous to allow air to move through the root system and by-product gasses to escape. Water - It must retain water enough in liquid and/or vapor form to sustain plants between waterings. Most plants can be grown without soil as long as we can provide air, nutrients, and water, (witness hydroponics). Here, I will concentrate primarily on the movement of water in soil(s).
There are two forces that cause water to move through soil - one is gravity, the other capillary action. Gravity needs little explanation, but for this writing I would like to note: Gravitational flow potential (GFP) is greater for water at the top of the container than it is for water at the bottom. I'll return to that later. Capillarity is a function of the natural forces of adhesion and cohesion. Adhesion is water's tendency to stick to solid objects like soil particles and the sides of the pot. Cohesion is the tendency for water to stick to itself. Cohesion is why we often find water in droplet form - because cohesion is at times stronger than adhesion; in other words, waterÂs bond to itself can be stronger than the bond to the object it might be in contact with; in this condition it forms a drop. Capillary action is in evidence when we dip a paper towel in water. The water will soak into the towel and rise several inches above the surface of the water. It will not drain back into the source, and it will stop rising when the GFP equals the capillary attraction of the fibers in the paper.
There will be a naturally occurring "perched water table" (PWT) in containers when soil particulate size is under about .125 (1/8) inch.. This is water that occupies a layer of soil that is always saturated & will not drain from the portion of the pot it occupies. It can evaporate or be used by the plant, but physical forces will not allow it to drain. It is there because the capillary pull of the soil at some point will surpass the GFP; therefore, the water does not drain, it is perched. The smaller the size of the particles in a soil, the greater the height of the PWT. This water can be tightly held in heavy (comprised of small particles) soils and Âperch (think of a bird on a perch) just above the container bottom where it will not drain; or, it can perch in a layer of heavy soil on top of a coarse drainage layer, where it will not drain.
Imagine that we have five cylinders of varying heights, shapes, and diameters, each with drain holes, and we fill them all with the same soil mix, then saturate the soil. The PWT will be exactly the same height in each container. This saturated area of the container is where roots initially seldom penetrate & where root problems frequently begin due to a lack of aeration. Water and nutrient uptake are also compromised by lack of air in the root zone. Keeping in mind the fact that the PWT height is dependent on soil particle size and has nothing to do with height or shape of the container, we can draw the conclusion that: Tall growing containers will always have a higher percentage of unsaturated soil than squat containers when using the same soil mix. The reason: The level of the PWT will be the same in each container, with the taller container providing more usable, air holding soil above the PWT. From this, we could make a good case that taller containers are easier to grow in.
A given volume of large soil particles has less overall surface area when compared to the same volume of small particles and therefore less overall adhesive attraction to water. So, in soils with large particles, GFP more readily overcomes capillary attraction. They drain better. We all know this, but the reason, often unclear, is that the height of the PWT is lower in coarse soils than in fine soils. The key to good drainage is size and uniformity of soil particles. Mixing large particles with small is often very ineffective because the smaller particles fit between the large, increasing surface area which increases the capillary attraction and thus the water holding potential. An illustrative question: How much perlite do we need to add to pudding to make it drain well?
We have seen that adding a coarse drainage layer at the container bottom does not improve drainage. It does though, reduce the volume of soil required to fill a container, making the container lighter. When we employ a drainage layer in an attempt to improve drainage, what we are actually doing is moving the level of the PWT higher in the pot. This simply reduces the volume of soil available for roots to colonize. Containers with uniform soil particle size from top of container to bottom will yield better and more uniform drainage and have a lower PWT than containers using the same soil with drainage layers.
The coarser the drainage layer, the more detrimental to drainage it is because water is more (for lack of a better scientific word) reluctant to make the downward transition because the capillary pull of the soil above the drainage layer is stronger than the GFP. The reason for this is there is far more surface area on soil particles for water to be attracted to in the soil above the drainage layer than there is in the drainage layer, so the water perches. I know this goes against what most have thought to be true, but the principle is scientifically sound, and experiments have shown it as so. Many nurserymen employ the pot-in-pot or the pot-in-trench method of growing to capitalize on the science.
If you discover you need to increase drainage, you can simply insert an absorbent wick into a drainage hole & allow it to extend from the saturated soil in the container to a few inches below the bottom of the pot, or allow it to contact soil below the container where the earth acts as a giant wick and will absorb all or most of the perched water in the container, in most cases. Eliminating the PWT has much the same effect as providing your plants much more soil to grow in, as well as allowing more, much needed air in the root zone.
In simple terms: Plants that expire because of drainage problems either die of thirst because the roots have rotted and can no longer take up water, or they starve/"suffocate" because there is insufficient air at the root zone to insure normal water/nutrient uptake and root function.
Bark fines of fir, hemlock or pine, are excellent as the primary component of your soils. The lignin contained in bark keeps it rigid and the rigidity provides air-holding pockets in the root zone far longer than peat or compost mixes that too quickly break down to a soup-like consistency. Conifer bark also contains suberin, a lipid sometimes referred to as natureÂs preservative. Suberin, more scarce as a presence in sapwood products and hardwood bark, dramatically slows the decomposition of conifer bark-based soils. It contains highly varied hydrocarbon chains and the microorganisms that turn peat to soup have great difficulty cleaving these chains.
To confirm the existence of the PWT and how effective a wick is at removing it, try this experiment: Fill a soft drink cup nearly full of garden soil. Add enough water to fill to the top, being sure all soil is saturated. Punch a drain hole in the bottom of the cup and allow the water to drain. When drainage has stopped, insert a wick into the drain hole . Take note of how much additional water drains. Even touching the soil with a toothpick through the drain hole will cause substantial additional water to drain. The water that drains is water that occupied the PWT. A greatly simplified explanation of what occurs is: The wick or toothpick "fools" the water into thinking the pot is deeper than it is, so water begins to move downward seeking the "new" bottom of the pot, pulling the rest of the water in the PWT along with it. If there is interest, there are other simple and interesting experiments you can perform to confirm the existence of a PWT in container soils. I can expand later in the thread.
I always remain cognizant of these physical principles whenever I build a soil. I havenÂt 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 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 ½ BB size I leave it out of soils. Compost is too unstable for me to consider using in soils. The small amount of micro-nutrients it supplies can easily be delivered by one or more of a number of chemical or organic sources.
My Basic Soils
5 parts pine bark fines (partially composted fines are best)
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime (or gypsum in some cases)
controlled release fertilizer (if preferred)
micro-nutrient powder, other continued source of micro-nutrients, or fertilizer with all nutrients - including minors
Big batch:
2-3 cu ft pine bark fines
5 gallons peat
5 gallons perlite
2 cups dolomitic (garden) lime (or gypsum in some cases)
2 cups CRF (if preferred)
1/2 cup micro-nutrient powder (or other source of the minors - provided in some fertilizers)
Small batch:
3 gallons pine bark
1/2 gallon peat
1/2 gallon perlite
4 tbsp lime (or gypsum in some cases)
1/4 cup CRF (if preferred)
micro-nutrient powder (or other source of the minors)
I have seen advice that some highly organic (practically speaking - almost all container soils are highly organic) container soils are productive for up to 5 years or more. I disagree and will explain why if there is interest. Even if you were to substitute fir bark for pine bark in this recipe (and this recipe will long outlast any peat based soil) you should only expect a maximum of two to three years life before a repot is in order. Usually perennials, including trees (they're perennials too) should be repotted more frequently to insure vigor closer to their genetic potential. If a soil is desired that will retain structure for long periods, we need to look more to inorganic components. Some examples are crushed granite, pea stone, coarse sand (see above - usually no smaller than ½ BB size in containers, please), Haydite, lava rock (pumice), Turface or Schultz soil conditioner, and others.
For long term (especially woody) plantings and houseplants, I use a superb soil that is extremely durable and structurally sound. The basic mix is equal parts of pine bark, Turface, and crushed granite.
1 part uncomposted screened pine or fir bark (1/8-1/4")
1 part screened Turface
1 part crushed Gran-I-Grit (grower size) or #2 cherrystone
1 Tbsp gypsum per gallon of soil
CRF (if desired)
Source of micro-nutrients or use a fertilizer that contains all essentials
I use 1/8 -1/4 tsp Epsom salts per gallon of fertilizer solution when I fertilize (check your fertilizer - if it is soluble, it is probable it does not contain Ca or Mg.
Thank you for your interest.
If there is interest, you'll find some of the more recent continuations of the thread at the links below:
If you were benefited by having read this offering, you might also find this thread about Fertilizing Containerized Plants
helpful, as well.
I am having trouble understanding how you are able to grow in such small depths as an inch of the gritty mix. In my experience it dries very fast (by design), but wouldn't such a small volume dry out in only an hour or two simply by evaporation? I have had success with it but using deep containers seems to work best for me.
Also, would you recommend pure turface for sp. which grow in swamp like or flooded conditions for months of the year? It seems I would need a lot more water retention than the 1:1:1 for this type of planting.
Al: You're quite the knowledgable dude! =)
What do you think about the mixes below? I have them readily available from a local nursery & probably am going to use them for almost all of my container plantings this year.
Barky Beaver Professional Grow Mix
Which one would you recommend for container veggies? I have the Professional Mix more readily available, but the Potting Mix looks a bit better.
Thanks! - Steve
Greg - Since a great deal of my focus is on bonsai, I grow lots and lots of plants in 1-2" of soil, which is always the gritty mix. Other than a greater commitment to watering, I don't think it's any more difficult to tend plants in shallow containers, AS LONG AS the medium holds no perched water, or very little perched water. You would think that heavy soils, because of their greater water retention, would make it easier to grow in shallow containers, but most plants quickly rebel at being in a soil with a PWT that occupies up to 100% of the soil in some cases.
For best vitality, you need a soil that holds no, or very little perched water when using shallow containers. Occasionally, I'll have a plant in a very small container that needs watering twice per day during the heat of summer, but most plants, even those in very shallow containers (1/2" - 2") only get watered daily or every other day.
Steve - it's hard to say w/o seeing them because it depends on what %s of each ingredient goes into the mix and how large the particle size is. I would probably tend to go with the mix that has the larger fraction of pine bark and seems more open. I might even increase the bark or perlite fraction, but it's hard to tell from here. ;o)
The pine bark size is small. Fines, if you will. The sand % is the only thing that worried me up front, but it's max 2-3% probably. I don't think it has an actual % written on the bag (maybe, maybe not), but it seems to be abbout 50-60% pine bark, 20-30% peat & 10% other stuff, to my best estimation. I thought, at first, about using this mixed with a bit of Perlite, which I may still do.
All right, so I posted in the X thread:
"I will soon be planting some roses in 20" terracotta pots on my deck. I would like to use something like the gritty mix, but lighter. The pots themselves are already so heavy. I found large bags of pumice locally, which I think seems a heck of a lot lighter than the granite would be. I read in another thread that pumice retains less water than Turface, but more than granite. Could I use 2:1 pumice:bark? What level of water retention would be best for the roses?
I am excited about how I think the gritty mix (or similar) will solve so many problems I had in the past, but I am a little scared of the watering frequency."
So today, I screened some Turface, pumice, and bark. I then measured and weighed 1 cup of each screened ingredient, plus the gravel:
DRY 1 c Turface weighs 167 g (5 7/8 oz)
DRY 1 c pumice weighs 165 g (5 3/4 oz)
DAMP 1 c gravel weighs 364 g (13 oz)
WET 1 c Turface weighs 300 g (10 1/2 oz)
WET 1 c pumice weighs 236 g (8 1/4 oz)
SO, now I'm wondering. . .what about using perlite to further lighten the mix? I assume perlite holds little to no water; is that correct? Would perlite manage to stay mixed throughout (assuming similar particle size), or would it uselessly float to the top? Would it hold up over time? Although I would like a lighter mix if possible, it's very important to me that it still be durable.
(As an aside, it really is a leap of faith for me here to try these ingredients. It just doesn't LOOK like something fine little roots would be able to grow in! It crossed my mind to wonder if this forum is a huge practical joke played on frustrated container gardeners, making them search all over creation for the ingredients, figure out a way to screen them...then watch all their plants die in this bunch o' rocks and bark!)
I'm assuming you forgot the smiley after your aside and that it was offered in jest.
Perlite holds quite a bit of water, @ about 3/4 quart per gallon of perlite. 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. It will stay mixed fairly well and it will hold up longer than it's prudent to go between repots.
I use Perlite in my mixes, and it stays mixed as Al says.
The only Perlite that floats to the top....was pretty close to the top to begin.
I apply a little extra pumice for top-dressing, and the Perlite stays where it should.
Thanks for the info. on Perlite, Al.
My early gritty experiments with Pumice and Perlite held much, much more moisture than I was
expecting. But that's the problem with trying to substitute materials ;)
For uniform and reliable results, one really should invest in the specific ingredients.
Thanks, Al!
Yes, of course in jest. . .it's just soooooo different from the small-particled brown stuff I'm used to planting stuff in.
Of course, I'm hoping for different results as well, so here goes!
The guys at John Deere Landscaping asked if I am doing this for a science project. :-)
That's interesting about the perlite's water holding. It sounds like I could come up with a perlite/pumice/bark mix that would hold the same amount of water as the standard gritty mix. But I am guessing that it is advantageous to instead have an ingredient like the granite that holds no water. However, filled with the standard gritty mix, these pots would weigh well over 100 pounds.
I've got 2 different mix samples in pots on the deck right now to test how long before they get dry.
Thanks again for your help!
Most of us who have been participating in forum discussions have all been repeatedly admonished not to water on a schedule, that we should always water container plantings on an 'as needed' basis. That presents some pretty serious complications if you're tending some 300 containers like I do in the summer because there is no way I can remember what plant got watered when, and I simply cannot make enough time to check each planting individually.
Let's quickly look at WHY that advice is so often parroted. Some of the more perceptive people growing in heavy soils have realized that watering on a schedule virtually guarantees that at least some of your plants are getting over or under-watered.
If we pick an arbitrary interval of 1 week between watering plants in a heavy soil, it's not difficult to imagine that if you have 20 plants, a few of them might be drought stressed after a few days and might even wilt, which can be a blessing, because you can at least see there is an issue and correct it. On the other end of the spectrum, you may have plants that still have a considerable amount of water in the pot, even if the soil feels dry. Watering these on your weekly schedule simply adds additional water to already saturated soils and sets the stage for assorted problems associated with that root condition.
Now, imagine that you're growing in a soil that holds no saturated layer of soil at the bottom of the pot. I'm not suggesting that it's impossible to over-water plants in a soil like this, but it's certainly more more difficult, and you have broad latitude insofar as the frequency with which you CAN water w/o negative consequences. So, in these soils you actually CAN water on a schedule, as long as you use some common sense. Even soils like the 5:1:1 mix enjoy a much larger margin for error over peat/compost/coir-based soils because of their open nature and inability to hold significant amounts of perched water for extended periods.
A large % of my plantings get watered every day in the summer, whether they're in the 5:1:1 mix or the gritty mix. This is partly by design - I try to use a container size/soil/plant material that will allow me to water daily. Some plants get watered every other day, and some every 3-5 days, depending on a variety of factors. I'm still making decisions, but they're decisions I don't have to spend much time on because of years of experience growing in the soils I use and having tended the same plants, often for 15 years or more.
When you water the gritty mix, the soil is wetted in a cone shape. The slower the water is applied, the wider the cone, so it is best to apply at low rates for longer intervals, or to use more than one emitter for larger containers.
Thanks to all your gardenweb coaching, I have finally assembled the right size bark (finally drove to Southern NJ and bought beautiful fine orchid bark from an orchid grower!), Turface MVP, and the Grower Gran-i-Grit and the Gypsum so now I need to re-pot my numerous containerized Japanese maples (outside)and my polyscias e.g. Ming aralia collection (inside).
My questions today are:
1) my Japanese maples are already leafing out and they all
really need to be re-potted. Is it okay to replant them now
in the gritty mix or should I wait till they are really
leafed out in late spring/early summer?
2) do you know how polyscias e.g. Ming Aralias take to the
gritty mix?
Thanks always for being so generous! You truly are the maven of the containerized soils!
Where do you purchase these ingredients?
Other than peat moss (and maybe perlite) the only place I can think to purchase the rocks would be a rock yard, and I do not want truckloads of this stuff. Home Depot and Lowes do not sell this stuff, and there are very few nurseries left around me, and most of them are either wholesale only or sell horribly root-bound plants at exhorbitant prices.
Can I use pea gravel as an ingredient? I bought a bag to plant some Hens and Chicks in. What about those decorative marble chips they sell in bags? If I crush them even smaller? The only stuff I've seen in bags are the decorative rocks. I can't even find decomposed granite around here.
As for bark fines, can I use pine bark mulch and chop it up; what can I use to chop it? What about Spruce? I have a ton of fresh Spruce chips and twigs and needles from an uprooted tree. Is this safe to use?
Any info on where these individual ingredients can be purchased (especially on Long Island, NY) would be great. Nurseries around me sell ready-made for lazy people stuff and charge a fortune for it.
Taruvara - Thank you for being so kind. ;o)
I hate to say it, but maples should be repotted before they leaf out. How old are they? How far along in their spring flush? Ever been repotted (not potted up) - badly root bound? Maybe we can work something out to get you by until next spring.
FWIW - if you like Japanese maples, you might want to consider Acer buergerianum (trident maple). They are wonderfully vigorous in containers, look like Jap maples, and respond very well to pruning, both above and below ground.
Nat - in the kindest way I'll point out that most of the questions you're asking indicate you've not yet made yourself familiar with the principles behind the soils being discussed. The questions are answered in detail many times in this and many other threads on the forum. Just giving you 'yes' and 'no' answers won't help you much, so I'm going to suggest you do a little reading & then come back for any help you might need.
In the meanwhile, perhaps others will be able to help with some of the 'where can I find' questions. ;o)
Well, my test batches of gritty mix and gritty mix-lite (pumice instead of granite) seemed to dry out way too fast on my deck. I put 3 cups of each in small clay pots on the deck, and my wooden skewers came out dry after about half a day.
Now I am putting out 3 cups of 100% turface, unscreened, to test. Any thoughts? Am I misreading the moisture of this stuff?
Thanks. I first soaked these mixes Friday night around 5 pm. Saturday by noon they seemed dry. Watered again thoroughly Saturday noon, was gone Sunday. Sunday and Monday were cool (60ish), cloudy, windy, with light rain at times. Rain cleared up by noon Monday, and by 4 pm, mixes were dry. Sun beats down on them till about 3 pm.
Watered them again this morning at 7:30, plus watered a clay pot of unscreened turface, and right now I have moisture in the bottom third only of the turface and the bark/turface/pumice. It is about 70 degrees, no breeze, and sunny. The air feels nice, but the sun is intense. The deck has a solid painted stucco floor that gets hot in the afternoon. But July/Aug/Sept will be much hotter and with more hours of sun than right now.
Do I have the right stuff? I bought a bag that says "Turface All Sport" "keeps the game going" at John Deere Landscaping.
Well, I REALLY want to use some variant at least of the gritty mix. . .another thread "How often do you water..." gave me an idea that maybe my wooden skewers/chopsticks are actually bamboo and not very absorbent. So I stuck 'em in and checked back about an hour later, and there was some moisture further up the sticks than before, about 3" up out of 4" total, for both the plain turface and bark/turface/pumice. The standard gritty has moisture only on the bottom 1/2" out of 4" height.
I also figure the small quantity is going to dry out faster than the big pots (though the big ones will also have roots sucking water out), so I dug out a much larger 12" pot, filled it with turface and soaked it. I'll see how long it will hold moisture.
This has been trickier than I thought it would be to adjust the water retention and weight; I sure hope I can hit upon something workable that won't require water more than once a day in the hottest months. But I'm so excited about the possibility of using something that won't turn into a swamp that then dries out like concrete!
By the way, the bag of pumice I bought says "Natural ORGANIC pumice." I normally accept that words change meaning with how people want to use them, but using the word "organic" for ROCKS bugs me.
FWIW - I grow a LOT of plants that are extremely large for the volume of soil they are in (read 'bonsai' and plants growing on for bonsai in the gritty mix), and I have no trouble going 2-3 days on most plants unless it's windy with low humidity and temps at >80*.
I suggest you stick something that wilts easily in a pot of the gritty mix and see how long it goes w/o wilting (after it's well-established) before you get too worried. I think you'll be surprised. You're just not used to it yet.
Hey Al,
I have another question. I couldn't resist and bought some new trees I want to grow in containers. My question is do I need to wash off the old soil when I transplant into the Gritty Mix?
What happens if I don't wash off the old soil?
If they are still dormant: I would bare root them before planting.
If they are not: it sort of depends on what kind of root mass they have. If they're just little guys, plant with root mass intact, but if they're larger, it's probably better to at least loosen the root mass before planting, especially if they are root bound or have encircling/girdling roots.
I'll let you describe the size of the root mass & how tight the roots are before I go any further; but generally it's bad form to have dissimilar soils in the same container.
Is there any reason I couldn't grow some tree seedlings in straight pine bark (from fines to 1/2 inch)and not add perlite or peat. You have mentioned before about leaving out peat if not sifting out the small fines (less than 1/8) but what about the perlite. What is it its role? I am only planning to leave the trees in the pots, mostly 1g, for a year or less before planting them out.
The perlite tends to wedge itself in between the bark flakes and keep channels open for water and gasses to move freely through the soil. You could probably use just the bark if you wanted to, if turns out that it's an appropriate size. Remember to lime.
Thanks Al,
I found a bag of calcined clay kitty litter at the store. I have soaked it for days and put it in the freezer overnight. It holds together except for when I really squeeze a piece and then it will break down. The manufacturer also make a soil conditioner that "remains in the soil indefinitely. It will not blow away, break down or dissolve." When I contacted the company they stated they were both the same products. The size of the particles seem perfect with no screening needed. Do you think this product would work? Or no because I was able to break it down when I squeezed it?
It sounds like it should work ok, but in my experience these products usually all need screening if you're going to make the gritty mix. If you're just going to mix it into pine bark like you were discussing above, then you probably don't need to screen it. It looks like there are no perfumes or other additives that might be toxic to plants.
Good luck.
I bought my first japanese maples a week ago - a 36" tall green lace-leaf ("Viridis") and a 24"t red lace-leaf ("Tamukeyama"). Both were chosen for their mostly regular umbrella shape, and vigorous appearance. I intend to keep the canopy-like structure and hope to maintain them as long-term container trees (i.e. try to keep the trees under 7 feet tall for as long as possible). The trees have a nice even distribution of limbs in their canopies, with overall canopy diameter about equal to the total height. I mention the dimensions in relation to my first question, later in this post. I would like to grow them several feet taller, but hope to keep them "deck" size for as long as possible.
I have a nice new covered deck and open patio, on the north side of my house = all kinds of possibilities for best placement in my basically high-desert, zone 6 climate. Salt Lake City, Utah has a few very dry 100 deg days, and a few sub-zero nights, so I will have to move the containers as necessary - but I can figure that out as I go.
I really enjoy the scientific principles of Al's gritty mix and the PWT. I bought 3 bags of Turface yesterday and have arranged to screen my own granite at a local stone yard, from their huge "3/8's or less" pile (I tried to "hand" crush Lowe's decorative granite with a tamping bar and a lot of muscle, which was hilariously slow and sweaty - about 3 pounds of beautiful grit per hour of hard labor and a cup of sweat... LOL). Haven't got the bark yet, but I do have a couple of bags of nice composted Ponderosa pine to add to my vegetable garden ... :-(
After hours of pouring over these threads I would still appreciate a little advice.
1 - I understand the relationship between what's above ground and what's below ground, but I don't have the experience to estimate a preferable container size for the maples health and my decorating goals. I own two thick, glazed, clay pots that are 24" wide and 22" tall (about 2.6 cuft). If you were choosing containers for these varieties of JM's, would you please share with me an estimate of the size of pots you would most likely choose?
2 - Since I am hand screening the granite I can be very selective. In my hand crushing efforts I got a high proportion of 1/16 size granuales relative to the 1/8 to 1/4 size. I can easily create a product which is a careful blend of everything from 1/16 to 3/16", or more like very coarse sand, or more like very tiny gravel. I puntured the bag of Turface and it looks to be predominantly around 1/8". Should I do my best to match the granite consistancy to the Turface, or is the inclusion of some larger granite particles more conducive to aeration and best function of the mix?
(I studied the photos which have a fairly wide particulate size, just wondering if best performance can be acheived by reducing the spread so it is generally a little finer or a little coarser, or is the blend of sizes important for variety of root growth/health?)
3 - From the other discussions here I understand it is a bit to late to transplant - yah. My trees have full foliage and seem quite healthy. I had planned to transplant to their permanent homes ASAP, but now I believe it would be best to carefully cut away the existing nursury pot, and temporarily place the trees in a similar potting mix, until the trees go dormant again this fall. Then do the transplant next spring, before first bud. Do I understand correctly?
I value you experience and input very highly. It is time to get all my new vegetables, roses, and these two trees outside, where they can flourish. With your help, and all the excellent info in these threads, I hope to get off to an awesome start.
I am a bit worried I might get "hooked" though. Always loved Bonsai, but I killed my first two trees fifteen years ago, when I first tried my hand at it. Haven't tried since. But now that I have more time I'm giving gardening another go - and far more successfully. This is my second year of plant-scaping my new backyard - and I have high hopes.
Thanks... Don
Hey Al,
(This post is in regards to the Apr 8th post I made)
I finally got some free time to re-pot my 2 cherry trees I mentioned.
Upon taking them out of their containers I quickly saw why I had to water them so frequently. The poor trees were showing signs of being root bound. I must have spent about 15-20 minutes on each plant washing what little soil I could off the root ball. I would say I was only able to wash off 30% of the old soil. I then transplanted them into the Gritty mix and proceeded to water them down nicely to get them settled in. This was done yesterday 4/29.
I placed them next to a large tree to provide it with shade. They receive full shade until about 5pm and get sun until the sun sets.
Today 4/30 I got home to check on the trees. The one tree that I probably damaged the most roots on has almost all the leaves curling like a taco. The other tree also has some leaves that are curling like a taco but not as severely. I'm assuming this is a result of my transplant. Two quick questions.
1. Do I need to worry? Should I relocate the trees, water more or less frequently? I gave it the really nice long soak after I transplanted them and did not plan on re-water them for at least 4-5 more days.
2. Is there any thing I can give them to lessen transplant shock? B vitamins? Rooting Hormones?
1) This is a copy/paste from one of my other offerings: "The size/mass of the material and soil type/composition determine both the upper & lower limits of appropriate container size. Plants grown in slow soils need to be grown in containers with smaller soil volumes so that the plant can use water quickly, allowing air to return to the soil. This (smaller soil volumes) will cause plants to both extend branches and gain o/a mass much more slowly. Rampant growth can be had by growing in very large containers and in very fast soils where frequent watering and fertilizing is required - so it's not that trees necessarily rebel at being potted into very large containers per se, but rather, they rebel at being potted into very large containers with a soil that is too slow.
We know that there is an inverse relationship between soil particle size and the height of the PWT in containers. As particle size increases, the height of the PWT decreases, until at about a particle size of just under 1/8 inch, soils will no longer hold perched water. If there is no perched water, the soil is ALWAYS well aerated, even when the soil is at container capacity (saturated).
If you wish to grow in a large container - please do. Just be certain that your soil supports no, or very little perched water."
2) When you make the gritty mix, the two ingredients that are closest in size are going to have the most significant impact on drainage and whether or not the soil holds perched water. What works very well for me is usually the equal parts mix with the screened Turface being the smallest of the components, followed by the granite, which I estimate is about 50% larger than the Turface, and then the bark (largest) in 1/8-1/4" size. Most of the bark is concentrated more toward the 1/4" size. I estimate the sizes to be about 1/16-5/32 Turface, 1/8-3/16 grit, 1/8-1/4 bark. I would prefer the Turface was just a fraction larger and the grit a fraction smaller, but that's how it goes. ;o)
No matter which way you head on particle size, you'll be OK in the aeration/drainage dept - as long as you don't get TOO small, and you can always adjust water retention by +/- the Turface and grit. What you DO need to guard against is a size differential so disparate that the materials want to separate.
3) Too late to repot, but not too late to transplant or pot-up. I would unpot and take a razor knife and cut vertical slits in the perimeter of the root mass at 3" intervals all around the perimeter of the roots. Rip or cut off the bottom inch or two of the roots as well - then pot in the same container or pot-up a size & wait until spring to do a full repot. Maples tolerate root work extremely well, so don't be apprehensive. Have plans to secure the tree to the pot after the repot/root-pruning.
4) Oh! There is no '4'. I guess I should use it to encourage you to get into bonsai. Things you need to know:
* Even 1 tree is a commitment. You have to arrange for its care whenever you'll be away, and if you neglect it, they won't be forgiving for long. Several trees is very much like having a pet - even if you don't interact with that pet all that much. They still need care daily, or at least every 1-3 days. Lots of trees = lots of pets.
* Many people come to bonsai with a nurturing nature, and almost as many leave. The reason is because they soon discover they haven't the skills to keep their trees alive and the frustration of burying trees in mass graves gets to be too much. I went through this the first time I attempted my career (lol) as a bonsai artist. I learned that you have to understand enough about how plants work and their relationship with the soil they are in to keep them alive. I did my homework and paid my dues, which is why I can preach at you today. ;o)
Anyone who is willing to commit to their plants and to learning how to keep them alive and healthy will find a wonderfully rewarding challenge in their pursuit of bonsai.
Best of luck .....
Scuba - I think you need to worry. When I talked to you upthread at the beginning of Apr, I was careful to point out that it's ok to bare root a dormant Prunus, but gave some general instructions applicable if the tree(s) were in leaf, which basically said don't mess with the roots of seedlings and if the tree was larger only lightly disturb the roots when you pot up.
It sounds like you did a full repot on a tree in leaf? There is nothing you can do now but try to minimize transpirational water loss by siting the tree(s) in shade and out of wind and wait. I generally use Superthrive when I repot my trees. I set the pots in a container of ST solution and fill it (the container) with water to the soil line and let it soak for an hour or until the next repot is ready to go in. I probably use about 1/2-1 tsp in 2-3 gallons of water. This is the only thing I use ST for. It has never worked for me as a tonic - after loosely controlled tests on 6 different types of plants.
Make sure there is moisture in the soil surrounding the roots - but don't over-water. The soil surrounding the roots should be as wet as a well-wrung sponge. If the trees are small enough, tenting to keep humidity levels up would be very very helpful, but be sure to allow at least a little air movement around the plant & don't let the foliage touch the tent.
Good luck, Stan. I wish you well.
I just recently discovered this forum and can't wait to try the gritty-mix. (Turface is ordered, screening is purchased, source for grit and bark are lined-up. Even found the Foliage-Pro locally!) I too had a question about timing and whether to repot now or wait until next Spring. Would Al's advice for how to pot-up a Maple now apply to a Camelia currently in a nursery pot? I also have two potted citrus that suffered over the winter, wait for next spring to repot the Citrus too?
Thanks Al,
Exceptionally good of you to help so many. I have newbie insecurity mostly.
Fifteen years ago I lived alone, didn't have dogs, had never gardened, and traveled a lot, so the Bonsai never really had a chance... my bad...
Now I have a 2 dogs, I travel very little, and I have a newly remodeled/relandscaped backyard, where I have been gardening for the last 3 years. Much better odds for the trees today.
On question 1 - I had already studied and thought thru the posting you mentioned, and lots of others. It all connected together in my head a few days ago. I understand I can use any size pot from 2 gallons to 30+ gallons, by building an appropriate soil for the different size pots. Truth is I believe a quick estimate from you on a preferable size of pot, that you would normally use for the young JM's, is better than my next two years of experience. Afterall, you have done this hundreds of times, over many years, and your natural instincts will trump my best estimates, for the foreseeable future.
On question 2 - the perfect answer for me. I will screen all the small fines out of the Turface. Then screen the granite as near as I can to optimal size = just slightly larger than the Turface. Then screen the bark to a size somewhat larger than the granite. Mix 1:1:1, with ammendments. Use MG 24-18-6, with a little boost of vinegar, epson, etc... as needed. I will be ready next spring.
On question 3 - exactly what I planned. I already have two 0.7 cuft glazed pots with cast in openings for handles. This is a bit more than double the volume of the starter pots the trees are in now. I will mix up a quick draining and well aerated soil with small PWT - along the lines of your other soil. Give them the pruning described, and into their new homes, with as much of the existing soil, and as little unnecessary root damage as possible. I already made up some plastic tubing covered cords I will use to tie the trees to the existing handles. Then place them for lots of indirect sun and minimal wind, so they can reestablish root structure ASAP.
As for question 4 - I have always admired the Art of Bonsai. I plan to use this years experience with the JM's as a step towards the more advanced efforts. I am building a small hoop greenhouse this summer which should give me some additional advantage next year (not to mention lots of tomatoes and peppers... yum).
Perhaps, a slanted or twisted style Bonsai Juniper is in my future?
Thanks again... Don
Hi, Jen - the maple & camelia would be better repotted in the spring - before bud movement on the maple, but the potting-up instructions are pretty universal and will work for both plants.
The citrus is better repotted in the spring, but many people do repot in between growth spurts. As you see the top growth slow down, you can repot. I have friends that do this:
Saw the bottom 1/3 of the roots off. Remove 1/2 of the remaining soil by cleaning out pie shaped wedges & pruning the largest roots in those wedge areas. Refresh the soil in those wedges & leave the remaining wedges as undisturbed as possible. Next year, do the same thing, but remove the other half of the soil. Skip a year and start over.
I'm glad you're excited. I'm betting you'll be seeing better results with less effort. Good luck! ;o)
Hey, Don!
Sorry about neglecting the pot size question. I didn't see where you mentioned how large the soil mass is now - but maybe I missed it. I should have mentioned to you, if I didn't, that it's best to pot-up into a soil similar to the one your tree is in now & do the full repot next spring. Something like the 5:1:1 mix would be good, or a bagged soil with some bark mixed in and a wick in the drain hole. I suppose you should probably limit your container size when potting up into a similar soil to something not much more than 4" wider & 2-3" deeper - or close. When you repot into the gritty mix - it's all up to you.
I should have read your entire post first - before I started answering on a paragraph by paragraph basis. Some of what I said is superfluous - looks like you have everything covered. I can tell by the way you're approaching things that you're going to do very well. ;o)
Sorry if I seemed rushed. Party here tonight & I have chores to do and victuals to prepare. Lol
Sorry... I didn't mention the existing pots. I was thinking only about the proportions of the trees and the container size I imagined was best for them. I'm happy to say I choose pots that are very close to what you advised. Opening up the roots in a healthy environment should do wonders for the trees. I bought the 5:1:1 ingredients yesterday and I'm having a friend over to join in the fun - she is plant educated and has helped me along the last couple of years.
How the container size effects plant health and growth is what I am working hard on understanding now. With everyone's input here I am absolutely confident I can create an excellent growing medium, now I'm working on just "how much" to create to get the results I hope for?
You have so much experience with how JM's respond to different size containers and what is the most physically "convenient" size for the "Gritty Mix" Gardener, that I just wanted to harvest your mind - so to speak. What I was trying to ask is what size of pot do you "generally" choose to grow young JM's, in Gritty Mix?
I'll be putting my gritty mix together this summer and filling the pots so I'll be ready for next spring's transplant to the Gritty Mix. Can't think of a better place to store it than where it needs to be next year.
I'll continue lurking and learning, so that I can stay on course. To Al and everyone, I really appreciate the help and insight. Its good to know my new Japanese Maples have a chance to "live long and prosper"... (insert a great big smiley face here)... and I have you all to thank for it.
... Don
I know what you mean about the friend. For a good number of years I was fortunate enough to have a very good friend whose knowledge of plant material was second to no one I've known that didn't work with plants for a living, and she was much better than the lions share of those. We used to make many pilgrimages each year to distant locations in search of plant material for our gardens and containers. My stock question was "How would this work ______?" In the blank would be the location where I thought the plant would work well. Sometimes I'd get the nod & other times a thumbs down. We attended dozens of symposia and took advantage of hundreds other educational opportunities over he years. The date we usually journey the 120 miles or so to DET is fast approaching, but unfortunately, her husband recently retired from a position at Dow Chemical Co, and she has returned to her native Sweden. I'm sure going to miss my pal.
I guess I don't think about convenience much when it comes to my trees. I consider what's best for the plant, then go at things from that angle. With some attention to root work, your dissectums and other slow growers should be able to be kept in 2-3 gallons of soil for a hundred years or so. Just kidding - that's if you keep the top reduced, too. Letting the tops run, you should be able to go up to 10 years in no more than 3 gallons of soil for the slow growers, and maybe 10 years & 5 gallons for the upright & more vigorous plants. In both cases I'm considering regular attention to the roots.
I tell everyone that loves Jap maples to get themselves an A. buergerianum (often referred to as a Japanese trident maple). You will LOVE this easy to care for tree. I would buy the species tree to start, and stay away from the 'Naruto' cultivar. It's very difficult for even experienced growers to manage and keep looking good in a container.
Good luck!
Hi all! I'm new here and I just love all this information! I'm looking for the right soil mix recipe for my Improved Meyer's Lemon, Calamodin Orange and Satsuma Orange plants in containers. I could probably make up a wheel barrow full of soil to start, as I'm wanting to transplant all 3 of them.
Al, can you help me with this? As you may well know, they love acidic soil! Thanks!
They like an acidic soil solution. ;o)
Your citrus will do very well in the gritty mix. I've never seen a tree that didn't excel in it, and I probably have at least 80 different species of trees covering 20+ genera ..... maybe as many as 30 genera.
If I were you, I would repot in the spring, or as the trees slow top growth in preparation for a period of robust root growth.
Hello Anna,
The very first post of this thread explains the gritty mix.
And at the end are other links to more reading if you have a chance, it's well worth it.
It consists of Pine bark, turface, and grit.
It's some reading, but you really need to if you are going to try this. It will give you a better understanding of how it all works.
Anna, the recipe is at the bottom of the first post:
"For long term (especially woody) plantings and houseplants, I use a superb soil that is extremely durable and structurally sound. The basic mix is equal parts of pine bark, Turface, and crushed granite.
1 part uncomposted screened pine or fir bark (1/8-1/4")
1 part screened Turface
1 part crushed Gran-I-Grit (grower size) or #2 cherrystone
1 Tbsp gypsum per gallon of soil
CRF (if desired)
Source of micro-nutrients or use a fertilizer that contains all essentials
I use 1/8 -1/4 tsp Epsom salts per gallon of fertilizer solution when I fertilize (check your fertilizer - if it is soluble, it is probable it does not contain Ca or Mg."
I have a questions about the gritty mix. I have greatly enjoyed reading some of these posts and learnig about water movement and retention. Whenever I read about the gritty mix, I think of it as moving halfway from regular soil based planting to active hydroponics/aeroponics, where the roots are essentially held in place by a planting medium and are regularly doused in a solution of water and complete fertilizer, but otherwise have plenty of access to air. From the perspective of the biology and chemistry involved, they seem rather similar.
Is there any truth to thinking about it this way? If so, for people who are huge fans of the gritty mix would it make any sense to go all of the way and try out full out hydroponics?
I've used this analogy dozens of times:
On a scale of 1-10, with 1 being growing in the garden and 10 being full out hydroponics, container culture is probably a 7 or 8. The gritty mix is definitely an 8, so it's only a short hop to hydro/aquaponics from there.
I have just discovered these threads and am very appreciative for all the help and advice they provide, from you and all. My motivation is that we just completed a deck with integrated planters, and we are now planning the plantings. I have read many pages of the forum material, and gone looking for supplies. I think I'm on the right track, but would like your opinion and suggestions to keep me there.
We have six planters in all, ranging from 4 feet to 8 feet long. They are all 18" wide and 18" deep (almost 3 cu yds in all!). They are raised 18" off concrete pads, and the space around them is enclosed by deck facing (allows air flow). There is more shade than sun, though it ranges from full sun to mostly shade with indirect light). We want to plant a variety of perennials with some annuals, and I would like to add in a few dwarf boxwood if it works. Because of the sheer size of the space, we would like to purchase/create a hearty mix that will support plant growth and health for as long as it's reasonable before needing to replace the soil.
I have found a nursery willing to provide me in bulk a "professional grower's mix" that consists of pine bark, peat moss, perlite, and micro-nutrients -- don't know proportions and granule size yet, but will have a chance to inspect it before I buy. I'm hoping it's ground pine bark and good proportions.
I plan to put some drainage holes in the bottom of the planters (say 3/4" hole every 6-8"), and a small drainage layer (since you have emphasized these don't make a lot of difference), and cover the openings with insect screen or perhaps landscape fabric, to avoid soil loss through the holes.
Can you provide some advice as to my plans above, plus what I really need to look for when I inspect the mix, and what other things I should do/use to improve it for long-lasting utility. From reading all the posts, it sounds like I could add in some pea stone (is this the same as 1/4" washed pebbles? how much should I add?), which I presume I can get at a sand & gravel place in bulk - I am guessing the other options ("Turface", crushed granite,...) would cost me a small fortune. How about lime (though I'm expecting a professional mix would be neutralized already)? And what if any additional fertilizer/micro-nutrients should I add, and in what proportions?
Also, once started, is there a seasonal treatment (eg. fertilizer, micro-nutrients) which will help it last?
This is a large project which requires a considerable investment, so we'd like to do it right as much as possible, to be able to enjoy our initial plantings as long as possible.
Thanks for whatever advice and assistance you can give.
P.S. For the thread someone started to catalog where-to-buy info by state, i will be posting some NJ info to help.
It's really difficult to be specific about advice w/o knowing anything about the physical make-up of the soil, but I think that it would be wise to invest in a soil that has pine bark as the primary fraction, or supplement it with pine bark so it does. I don't know how favorably you would look upon being separated from enough cash to buy a half pallet (20 bags) of Turface, but I would consider doing that if you're entertaining the thought of extending the use of the soil to several years. If you did that, you might even be able to continue to use the soil indefinitely by simply mixing pine bark into it each year to make up for the shrinkage. Wicks would help if it started to get too water-retentive.
What are you planning to use for plant material? You've made allowances for the fact that plants in containers won't likely be hardy to the zone they're advertised to be hardy to?
It would be helpful if you had access to a micronutrient supplement called Micromax. It's expensive, at around $100/50 lbs, but you would have no problem getting rid of any you didn't use if you wanted to - you could probably break the bag down & make enough selling small quantities on Ebay to pay for the bag. Once you find out what kind of soil you're going to end up with, we can figure out how to deal with it before and after (subsequent years) you fill your containers.
I know I wasn't a whole lot of help, but there isn't much to go on yet. I'll be around if you think I can help with anything more. Take care, and thanks for your kind words .... and good luck!
Thanks for your response! Actually, it's quite helpful, since I'm flying blind! The additives you suggest would be an additional expense, but maybe we can talk ourselves into it, if it can really make the planting last a lot longer.
We can at least look into the Turface -- I located a dealer in my area. I see they have several products -- which one would I buy: MVP, or ProLeague with "smaller, more uniform particles", or...? And in what proportion should I add it to the mix? Whatever volume I buy, I would need less of the mix, so would take this into account.
For longer term renewal, I also found that Fafard makes "Aged Pine Bark", and that I can special order it through a local source, but only by the pallet :P I infer from what you're saying that over time the soil would "collapse", so should we just add enough to bring it back up to its original level, mixing as far down as we can without disturbing the plants?
Is the Micromax a product by Scotts? If so, I located that also at a nursery supplier not far away -- hadn't priced it yet, but it does look like I can get it. Do you need more detail on soil mix before suggesting how much to use how often, or are there instructions/standard guidelines?
One other question: the nursery supplying the mix said that pine bark is very acidic, and can be tricky to neutralize just right -- any comments on this? If so, what's the best way to measure pH, and, if we would need to add lime to neutralize the acidity, any suggestions on how to know how much to add?
Re plantings, we've been told the air around the planters allows the soil temp to drop much more than in-ground plantings, so to look for plants that can tolerate colder temps -- I presume that's what you mean. We're not too far from the ocean and the planters are somewhat sheltered, so I'm hoping this effect won't be too catastrophic.
Thanks again -- this is terrific help to keep me moving in the right direction -- if you don't mind, I'll let you know more specifics of the soil mix when I find out, and maybe we can refine the "formulas" a bit.
Buy MVP or Allsport (from John Deere Landscapes dealers.
"For longer term renewal, I also found that Fafard's makes "Aged Pine Bark", and that I can special order it through a local source, but only by the pallet :P I infer from what you're saying that over time the soil would "collapse", so should we just add enough to bring it back up to its original level, mixing as far down as we can without disturbing the plants?
I know JaG was using aged bark from Fafard's, but I don't remember him saying how he liked it. I bought several bags of it last year and used it in 5:1:1 mixes, but I'm not going to use it this year. It worked ok, but it was too fine and water-retentive for my taste. I think you'd be better served if you tried to find a source of uncomposted fines or partially composted fines that weren't quite as fine as Fafard's Aged Pine Bark. Remember, you'll be trying to breathe aeration back into an aging soil, so you'll want larger particulates than you'll find in the aged bark.
Micromax is made by Scott's. Use 1 oz/cu ft.
Nothing tricky about adding dolomitic lime to a bark-based soil. Add 1/2 cup/cu ft or a tbsp/gallon. There is no need to measure the pH of your soil. The Ca fraction will complete its reactive phase & enter the residual phase when the pH approaches 6.0.
Because you won't have the considerable moderating effect of the earth's heat to help keep the soil temperature warmer than ambient temps, you should choose your perennial material (trees & shrubs are perennials, too) so they are hardy to least a zone or two colder than your zone.
Any time any one has questions or comments offered in a way that promotes an amiable exchange of information, they are always very welcome.
Take care. TTYL
thanks, thanks, thanks! great info, and I'm feeling like I'm learning more, and getting close to knowing what to do. Still a few things I'm not clear on, and would like your opinion....
On the Turface MVP, I found a good PROFILE Turface article, and they recommend a 15% mix by volume with soil. This would mean about 4 cu ft per cu yd, and it said Turface is 35 lbs/cu ft, so that's 140 lbs/cu yd. Would you agree with this proportion for a mix, or want to go higher?
On the MicroMax, how often to treat at this level -- is this once per year at the beginning of the season?
On the pine bark, message received on the Fafard. I saw in one of the threads that Agway sells a pine bark mulch with irregular pieces, the larger ones just over dime size per the pic -- I verified I can get this too, and can buy by the bag. Are these pieces small enough for this task? If not, I'm not sure what size I'm looking for, or what brand would work -- can you help here?
Thanks again,
Hi Al,
Just came across this great thread; thank you for all that info! You mentioned that one can simply improve drainage by inserting a wick into the drainage hole of the pot. I don't want to replace the traditional potting mix I've been using in my containers (at least not before trying some other options). What should I use for the wick? Self-watering containers usually use string, but will that work if inserted into the drainage hole? Thanks,
Boxxer - be careful to note if the article was about amending the mineral soils (as in golf courses and ball fields). If you plugged the Turface into the place of perlite in the 5:1:1 mix, you would find it coming up as 1/7 or a little over 16% of the mix. Because you are using it to help reduce shrinkage and increase longevity, it should probably have a greater presence in your mix, if it doesn't beat up your pocketbook too badly. ;o) I like the Turface as opposed to something like a small nonporous gravel because the roots can grow into the Turface particles and it has a much greater CEC. (more research) ;o)
Each spring, I use a condiment shaker to lightly sprinkle Micromax on the surface of containers I'm not repotting that year, and then scratch it into the surface soil. You can probably get away with skipping this altogether if you're using a fertilizer with all the minors - like Foliage-Pro 9-3-6.
The 5:1:1 mix is in the middle. The other bark samples are all from different suppliers and what I had on hand when I took the pic. The 3 at 3, 6, and 9 are all suitable, especially the 2 at 6 & 9. The one at the top is fir bark and what I use in the gritty mix.
El - use an old shoelace that isn't cotton, or a strip of 100% rayon (man made chamois) or a strand from a 100% rayon mophead. Almost anything that will wick water upward a couple of inches and won't rot is suitable when used for drainage applications. Fold the wick over the blade of a straight slot screwdriver & use that to push it up through the drain hole and into the soil.
I'm grateful for your mentioning you appreciate the info.
Take care, guys.
Super Al, thanks! Now I need to sift through all this and get my plan together....and find out what my promised mix looks like too. You have given me a lot of great info to go on. I think I'll be OK.
In the picture of the pine barks, i'm trying to gauge the size (no dime reference on that one). for the pine bark at 3 o'clock, how big are the biggest chunks....are they maybe 3/4" or maybe even 1"?
Thanks again for all your help!
Hey Al, have you ever considered going all entrepreneurial on us and selling your formula in pre-mixed bags? I think that is what happened with the Square Foot Gardening soil mixes (Mel's mix), and it only has three easy-to-find ingredients. Your mix can be a little more challenging when it comes to gather up the individual materials.
Having Al market this is a nice thought..
But it's not really a one size fits all mix.
The beauty of Al's is it can be tweaked, depending on where you live and what you need. So you may still need to hunt things down. :)
Ive had a challenge with the grit, but at the same time, have enjoyed it in a weird way.
I like being able to adjust things for what each plant needs.
Most big box stores carry it at this time of the year in 50 lb bags. Most large garden centers that sell Espoma products carry it in 120 lb bags. Any rural outlet that sells fertilizers (like feed stores and grain elevators with farm supply stores associated with the operation) is likely to have it.
If you tell me where you live, I'm sure I'd be able to locate a very near source in less than 10 minutes on the phone.
Here is a quote from Al, that is meaningful to me. "When you water the gritty mix, the soil is wetted in a cone shape. The slower the water is applied, the wider the cone, so it is best to apply at low rates for longer intervals, or to use more than one emitter for larger containers."
My little container vineyard (complimentary from UC Davis cuttings) will be on emmitters, first year, 3 gallon, then 5 gallon, then 10 gallon, and possibly higher. Good information that I may need 2 or 9 emitters depending on the size.
Al, help me here. Is there a formula for emitters per size of surface? Like 7" across, 12" across, 20" across, etc?
Thank you!
Your fan, Suzi
Well I'll be darned! I was hoping that some day I'd make a favorable impression on you. If you want to know why, you'll have to ask off forum. ;o)
I don't think there is any sort of 'rule of thumb' about the number of emitters required to evenly/adequately supply moisture to a container based on diam or container size. The reason I say that is because there is a wide variance in soil textures as a function of particle size. The heavier soils would need fewer emitters or only 1 because the water is less affected by gravity and more readily moves laterally/horizontally through those soils. Well-aerated soils like the gritty mix have less capillarity, so they tend to move downward rather than laterally, so need more emitters, lower flow rates and flow times, or just longer flow times.
I know that didn't help you a whole lot, but I think the upside of this is that I would expect the time it takes to gain the experience to make decisions based on your own intuition will be short. I guess you'll have to depend on experience being the best teacher in this case. ;o)
Good luck, Suzi
Hey, Al! If you'll remember, a few weeks back I asked a couple of questions on the gritty mix via email about plant particulars in gritty mix and fertilizing. I must admit, when I first heard of the Gritty Mix, I thought it was a ton of work for little results and that I could get by on MG potting mix or similar. Well, I learned several hard lessons that showed me quite pointedly that I needed to change some things in my gardening techniques. You might be pleased to know that I'm now on my second big batch of Gritty Mix! I repotted nearly 40 plants already, and there's more to come! lol I love the stuff, and I've definitely converted my husband, as well as several friends :) My plants are starting to take off, except for a few that are big box store rescues that are still rehabbing(and the ones I haven't finished repotting yet). Thank you so much for this great info :)
Loving - that is pretty powerful testimony - thanks. Most of all though, I'm glad you seem to be excited about the prospects of getting more enjoyment for your efforts, and you're sharing your enthusiasm with your friends. It's just a lot easier to get great results with the right soils, and you have a lot more room for error.
FB - for gypsum:
Miller's Country Store
1148 Old Trail Rd
Clarks Summit, (570) 586-6006
$7/40 lbs
John Deere Landscapes
1000 Springbrook Ave Unit 1
Moosic (570) 451-7450
about $13/50 lbs
Quick question. How long does it take for both gypsum and lime to be totally "used up" in container soil mixes? In other words, if I use gypsum and lime to build the grit and 5-1-1 mixes respectively in early spring (March), will the gypsum and lime be totally depleted by the end of the current growing season (October/November)?
I may have to reuse some soil mixes next year and didn't want to add gypsum and lime to the reused soils next spring *if* they still are providing Mg and Ca.
It varies. The Mg fraction of dolomitic lime is about 125x more soluble than the Ca fraction, and gypsum is much more soluble than dolomite. Add to that the fact that soil solution acidity (or lack of) also plays a big part in how soluble these elements are, as does water alkalinity, and you can see there is no way to say with any certainty.
What I do: sprinkle a little gypsum (in the spring) on top of the gritty mix in the second and (if required) third year of the plant being in the same pot/soil combination.
For plants with dolomite (5:1:1, usually), I simply include a little Epsom salts in the fertilizer solution for any plants in the mix for the second year.
Aluminum insect screen and a 3/8 inch black plastic nursery flat.
I also rinse my materials in a large pond-basket, which has openings
around the outside that vary from 1/16 to 1/8 of an inch.
I mix in plastic bags, in a wheelbarrow bed, or in a tarp for large batches.
I am a bit of a free spirit. Indian Nation! Cherokee/Mohawk Yikes! two sides, so, I look at the earth, and the plants grow in soil with all kinds of sizes of rocks, whatever. The roots find a way around. There is no size requirement! For drainage or nothing!!
In a container, there needs to be drainage, so, why sift? I don't and I won't! If the pine fines or the granite blocks the drain holes, well, you need to fix that, but sufficient drain holes should create free drainage. I do believe in air pruning, so my containers have holes on the sides as well as the bottom.
I got slapped in a different thread, and JD and I thought about it, and we decided...... Mix the stuff. We are both too lazy to sift!
But, I will tell you, I have a tool called a "soil sleuth," Google that, and you can easily see the wetness or dryness of the container soil with it.
That's it!!
I have no dog in that fight. ;o) I just lay out the science and let you decide what's best. Your thoughts are interesting, but growing in containers is quite different from growing in the ground. I screen ingredients for the gritty mix for a reason - to eliminate a perched water table (PWT) so (fine) roots don't die while a PWT is present in the soil. If your grow bags are resting directly on the ground, they're raised beds, from the perspective of soil hydrology, and you can get away with things that would be counterproductive in conventional containers.
Best luck.
Jeeze Al!! No disrespect. I think you are da man!! We all do, but, you know me by now. I will kick it up!! You have no dog? Well, you need to fix that! Like now!! A Yellow Lab would be best!
I don't see containers, and living plants much different than I see recipes, like add something, delete something.
Here is what I see. I am a native American, and we listen to the earth. I also see that you are a chemist, and everything must be exact. I only do containers because I have exhausted my earth. And you gave me, the desert dweller, a recipe for my container vines.
I appreciate you, Al!! And I listen! But, you know!! I will deviate! It's the free spirit in me. HUGE!
I hate getting slapped, so please do not!!
Why would you think I was trying to slap you? I have no dog in that fight = I have nothing to say about what course you set, which acknowledges your freedom to deviate 'til your heart's content; so we're on the same page, there.
There's more than enough info in this thread and floating around the forum to make it easy for people trying to put a soil together to make their own decisions ..... and I'm always around to answer the questions put to me that I can answer if more input is needed. Beyond that, I can only hope the course anyone steers takes them exactly where they want to go. If it doesn't, at least there's enough information that you should be able to sort out any problems.
I think you probably read more into what I said than what is there.
Take care.
I have been making 2 different 5-1-1 mixes and just now am wondering if I am making things harder than they need to be.
I have a lot of citrus so I put gypsum in that mix. Most actually go in gritty with gyp but I do use some 5-1-1.
For my figs and vegetables and misc others I have mix with lime.
I am quite sure the citrus would not like lime (and higher pH). Would my others do okay with gypsum and allow me to make just one mix?
Al, thanks for answering my question a few posts above regarding lime and gypsum durability. Sounds like there is no way to tell when lime and gypsum are depleted in the grit or 5-1-1 soil mixes.
If I decide to reuse the grit mix for a second season and add fresh gypsum to the top of the soil as you indicated there's no danger in having too much gypsum in the soil? I wasn't sure if having too much gypsum in the soil mix would be a problem for the woody plants or if they would just take what they need and ignore the extra gypsum or if it would cause root burn or nutritional/growing issues.
Thanks Al
Hi jojosplants,
I have managed to locate the 1st ingrediant Turface in Arizona(ewing store). Where did you find the other two ingrediants(grit and pine/fir bark). Could you please share with us.
I've called 15 feed/garden stores with no avail. In phoenix most of the products are forest product(composted). Could you please help
Thanks Josh. I can save them for the 5-1-1 mix no problem. Just didnt know if I could use those pine bark fines (basically pine bark dust) for seed starting or other things besides the 5-1-1 mix.
The pine bark I found at the local KMart is quite fine and good for 5-1-1 or grit mix, but just didnt want to toss that pine bark dust away if there was a use for it.
While looking on bonsai forums I found something called Hoffman's Bonsai Soil for sale on Amazon. Cost is $10.00 for 2 dry quarts, so it's expensive. I did some research and appears to be a mix of pine bark, turface, haydite and couse sand or gravel. The Amazon description says:
"Professionally formulated to provide optimum growth for evergreen and other bonsai plants, provides the plant support, moisture and drainage bonsai need, pre-mixed, ready to use, 2 Quart Bag"
Here's a photo of the mix:
Has anyone used this mix before? I'm wondering if this is a good mix for growing shurbs and trees in gallon-sized containers. How would this mix compare to Al's gritty mix?
I've used it before and it's very water-retentive, in addition to being very expensive. I don't think I'd want to put anything in it that won't tolerate wet feet well. It has a LOT of fine particulates ..... I'm guessing because they don't screen anything - they just dump it together.
Thanks for your thoughts on this mix Al. Do you think it would make a good mix if all the ingredients were screened or would it still hold too much water for most shrubs and trees?
Maybe I'll stick with what we know works, your grit mix of turface, pine bark and granite.
Thanks Al
Hi Nutcr0cker,
I'm sorry, but I did not see you post, I haven't looked at this thread in awhile.
I got my pine bark fines from John Deere landscape supplies, and I have not found the grit.
I call around and may have a source for silica sand, but no car to go look at it.. So still on hold for grit.
Hi Al,
First off a tremendous thanks to you for your generosity in providing so much valuable information to this gardening community. It has been incredibly humbling to spend countless hours reading through your threads on the effects of the perched water table, soil mixtures and fertilizing program for containers. I can't tell you how helpful and enlightening it has been to be exposed to these topics.
I consider myself an armature gardener, and I now have a much better idea why some of my plants had such a difficult time reaching their genetic potential. As background, I got into gardening about five years ago when I finally moved into a place that had a small backyard (albeit north facing). I went gardening crazy, planting and using about every square inch of my little shade garden and in the process added about 50 different containers.
The in-ground plantings seemed to do fine but my containers had mixed success. To complicate matters, I'm in San Francisco so I've tended to plant perennials as they make it through each year due to our mild year round temperatures (65 degree avg). Because of the shade and the low temperatures, I've always struggled with drainage for the containers. In addition because I use perennials I was using the same soil mixture in the containers year after year and had no idea it was quickly breaking down.
So I've learned a ton from your posts and now have a working plan to switch over the 50 containers to your gritty mix as well as starting a more regimented fertilizing regime per your other thread. I had a few questions though that I was hoping you could help me out with.
1) I've located all the components for your gritty mix with the exception of the "1 part crushed Gran-I-Grit (grower size) or #2 cherrystone". This has been a difficult one to track down and my local searches so far have been unsuccessful. I recently ran across a local landscape company that is selling "Roof Gravel: 75 lb pre-bagged, 1/4" black & white crushed granite " (http://www.broadmoorlandscape.com/construction_gravel.htm). Below is a picture of the product. Do you think this would work? If not I'll expand my search to grain/feed stores and call around (or if anyone has found something in the bay area please feel free to chime in).
2) Do you have any guidance on the process of transplanting with the gritty mix? I have a lot of fuscia's, abutilon (flowering maple) and Japanese maples in the containers along with an assortment of fillers and spillers. In San Francisco there really isn't a winter, so I'm not sure when the best time to transplant would be.
Also do you recommend taking off all the old soil when I transplant? Do I do this by soaking the roots in water or just shaking it off? Sorry I haven't done many transplants before.
Thanks in advance!
Hi, Kernul. Thank you for being so kind. It really pleases me that you find the potential for improvement in your growing experience.
1/4" is too large to be a good choice for the gritty mix. If you can't find something in the 3/32-3/16 range, you could probably sub screened perlite for the granite. A few people have been able to locate 1/8" pumice or appropriate size silica from masonry supply stores or roofing companies. I know there are companies in FL that sell filtering gravel in various sizes, some of them perfect. I'm fortunate in that I've been making the gritty mix for so long I've developed multiple suppliers for all the ingredients - well, almost. I prefer the pre-screened fir bark I get in CHI, but I do have several suppliers I can count on for pine bark that would work just as well after screening.
I've been helping a dear friend in Fremont with her trees for years, and she generally repots in the spring, though you could easily repot there in the fall after leaves drop.
I THINK you'll find repotting instructions in the link JJ left you. If not, and you still have questions, just ask & I'll do my best to answer.
Whether or not you should bare root entirely depends on the plant. Some plants tolerate it and go plugging along as though nothing happened, and others pout if you disturb to large a % of the root mass. Since I haven't repotted everything you're likely to be growing, it might be a good idea to ask on a plant by plant basis, or go easy until you see how they respond. It's likely though, that I will have repotted close relatives of many plants, so should have a good idea what kind of rootwork they'll tolerate w/o balking.
When I remove soil, I use various tools. I have rakes & root hooks designed to remove soil and straighten out wayward roots. I also make extensive use of a root pick, which you can simulate by sharpening a 1/4 - 5/16" dowel in a pencil sharpener & using it to 'pick' away at the stubborn soil pockets.
Repotting & root pruning just takes a little practice, but it is required if your woody plants are to have the opportunity to grow to their potential within the limiting affects of other cultural influences.
Good luck - I hope your enthusiasm continues to grow!
DH and I went out of town and driving home I saw a feed store...of course I had to ask if we can stop by to see if I can find some Crushed granite :o)(seems to be the hardest ingredient for me to find)out of all the ingredients. they did carry one brand and one size only... Crushed Granite by Manna pro...although its quite expensive at $5.50 for 5 lbs...but in a pinch or if you don't need to make a lot this would come in handy, I bought a bag so I have some to use later, wish I could find the bigger bags you guys are finding at much cheaper prices...but we can't be too picky when its slim pickins,lol...!
Al, do you think we still have to sift/strain or rinse this or is it good to go as is? Thanks!!
Hi Pug! So good to see you!!
I found the same stuff here, and in the same size and price. :( Manna pro does not make any bigger bag. :(
Mine seems dusty, so I'm going to rinse/sift(insect screen) just to be safe. :)
Like you I will keep it on hand for my small stuff. I'm thinking of using pearlite for the gritty and got 14" terra cottas for my tree's and hope they don't blow over. lol...
Hi Jojo...Good to see you too!! Thanks for the tip, I think I will go ahead and rinse/sift it too just to be on the safe side. I'm lucky I'm able to get the large bag of the coarse Silica sand for a substitute for granite but will save this bag for my "most favorite" plants :o)
Its a shame they don't sell the large bags of crushed granite in our area...oh well!
They don't here either! :( And everyone has chickens here! I used to ! Lol!! or the silica for that matter.
I found some gravel at a sand blasting supplier, but am having transportaion trouble.. Im going to call around for masonry supplies and roofing soon.
I still think he has a sense of humor. ;)
Take care!! Talk to you soon!
Looks good as is, Nance. I usually give it a quick shaking over window screen though, just to get rid of the dust. With such a small volume like you're working with, you could probably rinse it in a strainer. You know I use it for bonsai soil, and I don't even like that little film of slimy dust on the bottom of the container because it is a good place for root rot to start - especially in the small/shallow containers.
Lolol....You guys are too much...It is like gold if you can find it, especially in that amount ..
I can get the bags in 50lb ones for 13 dollars, not to make you feel bad though....Love you all and you know that..:-)
Pug, congrats, anything you find is a miracle there I guess..I am sure you will use that for your extra special plants!
Hi Jojo.....How aree the plants doing these days? You are both so lucky to still have all that nice warm heat...
Hi Al..:-)
Hi Mike!! You're so right...like striking Gold,lol... Yes, I'm reserving the crushed granite for my special plants, especially plants from my special friends :o)
I'm still in the 90's here...I'm actually looking forward to some low 80's...but its gonna be a few more weeks before I see that on a regular basis :o(
Would send you and Al some of this heat if I could!
Hi Al,
I've read many of your threads in this link and they have been extremely educational. I am new to the gardenweb forum. This is my first posting. I live in Southern Florida. I am about to start container growing tomatoes next month. The sixteen seedlings should be container-ready by the end of October. I really need to know in what proper proportion I should mix the components I have. I've gotten different mixing ratios from various people with some ideas but I trust your advice given the amount of knowledge and expertise you have.
Also, are the fertilizing components that I have ok?
I'm using 15 gal. plastic nursery containers(with cages) sitting on 8ft.X 10in X 2in planks of lumber supported underneath by cinder blocks.
The tomatoes are all indeterminate.
These are the soil components I have:
Pine bark fines, peat moss, perlite, vermiculite, composted cow manure, a calcitic and dolomite lime mix, epsom salts,and manganese sulfate.
The slow release fertilizer I have is 5-10-15.
I have a plant hormone/vitamin formula called "Superthrive" which is supposed to give the plants an extra boost and I also have dry kelp seaweed I can make into a tea after rinsing out the salt.
I know if I get the soil and fertilizers right, at least the plant's immune system will be strong enough to fight off most diseases. That will be one large worry behind me and then I can concentrate on watering, pests and other resistant diseases.
Your help would be greatly appreciated.
Hi, Jon. Thank you for the confidence and the kind words - both appreciated.
It would help if you would give some idea of the temps & o/a weather pattern you expect while you'll be tending your tomatoes. It would also be helpful if I had an idea of how 'fine' the PBFs are. Can you post a picture here of share one by email? Some small ratio variation of the 5:1:1 basic mix will probably serve you well, as it has others and as you've probably noticed in your travels.
Bagged manure usually turns out to be a little bit of manure mixed with a lot of black sand or sandy loam; besides, manure doesn't add anything to your soil you can't get elsewhere w/o the impact on drainage/aeration. You won't need the MnSO4, and probably not the vermiculite. The fertilizer is actually unnecessarily high in P and a little low in N, unless it was a typo & it's actually 15-10-15, in which case it would be better.
I've been starting my tomatoes on a 3:1:2 ratio fertilizer until they get some foliage. About when they hit the top of the cages, maybe 3 ft, I reduce the dose so the leaves just stay green & start adding a little Pro-TeKt 0-0-3 to the fertilizer solution when I fertilize. The silicon in the Pro-TeKt also hardens the plants against heat, insects, and disease. If that seems overly complicated, a 2:1:2 ratio fertilizer would be good (if you can find it - I don't know of any) or just a 1:1:1 ratio, like 20-20-20.
I've done some experimenting with the Superthrive, and this is what I found. (scroll down to my post)
Your turn. ;o)
Hi Al,
Thank you for your quick response. The pieces of PBF's are equal if not smaller than the size of an eraser at the end of a pencil. The temp. in Oct. and Nov. will be between 70 to 80 degrees.
Is the 5:1:1 basic mix ratio the PBF's - peat - perlite ratio?
I won't use the composted munure, vermiculite and MnSo4 as you suggested. The 5-10-15 was actually a suggested by someone to boost flowering and fruit growth without boosting too much foliage. I could try to return it or do you think it important enough to keep for the tomato-growing program in the future? Could it possibly be used in place of the Pro TeKt0-0-3 since it's high in potassium?
I read your post (thank you for that as well)on Superthrive and I think I'll use it only during the transplanting of the tomatoes to containers.
Over to you Al.
Yes, you understand the ratio correctly. Somewhere around the 5:1:1 ratio of PBFs:peat:perlite should work well in the weather you described. If the particle size of the bark is very consistent, you should probably use an extra part of peat. If particle size is sort of evenly distributed between dust & the size you mentioned, 5:1:1 is good.
You can add some flexibility to your fertilizer by combining it with 30-10-10 or alternating applications of 30-10-10 and your 5-10-15 until your plants have some size, then combine it 2 parts of 5-10-15 with 1 part of 30-10-10. Its difficult to make a case for any fertilizer for container culture that supplies a regular diet with more P than N, even when the goal is to reduce vegetative growth. most greenhouse crops are started on close to 3:1:2 ratios and 'finished' with nitrate fertilizers in a 2:1:2 ratio to inhibit vegetative growth and produce stout, sexually mature plants.
Good solution Al. I'll combine the 5-10-15 with the 30-10-10 as you suggested. As far as the amount of calcitic and dolomite lime mix to use for a 15 gal. container...would a cup be enough? and should it always be added as a slurry to the top of the soil? I know it's important for reasons of pH, and for calcium and magnesium content. I want to get the proportion right since it could raise the ph too high for tomatoes. Also I think you wrote in a thread that one should let the mix sit a couple of weeks before planting with it. Also is the kelp seaweed tea a wise choice for the feeding of micro-nutrients? Someone also mentioned a molasses tea for iron, potassium and carbs?
Is there anything to that?
Thank you so much being so clear and precise in your explanations and generous with your time. It's easy to follow your reasoning.
Thank you Al.
No problem, I didn't think you were. I had some problems myself with submitting a response on the forum this evening. I don't even know if this post will get through.
I'll probably check back into the forum first thing tomorrow morning.
I'll try again .... 1 cup of dolomite in 15 gallons is twice what you need. 1/3-1/2 cup is sufficient. How quickly the lime reacts depends on soil moisture and temperature. When it's warm and the soil moist, the lime can finish the reactive phase in only a couple of days.
You can do as you would like with regard to the teas and elixirs. I find them redundant if I'm sure the plants are getting a full compliment of the elements plants normally get from the soil. I use Foliage-Pro 9-3-6 extensively, because it supplies all the essential nutrients in favorable NPK %s and in a favorable ratio to each other. For the last 15 years or so, I'd say my plantings have done very well, but I don't think they've ever been better than they are while using the Foliage-Pro. It works exceptionally well.
If you're supplying elixirs and solutions with unknown ingredients/nutrients in unknown amounts, AND a fertilizer that is supplying all or some of the nutrients, there HAS to be redundancy. Nutrients added to the soil solution that go unused cannot improve nutrition, but they can make it more difficult for water and other nutrients to be absorbed, or even compete with other nutrients so too little of that nutrient is absorbed. This probably isn't a significant negative, the point being that it does no good to oversupply any single nutrient, and if your fertilizer program is all it should be, there is no need to introduce elements that promote the biological life that collapses the soil you were so careful to build. Gardens are distinctly different from containers, which are much closer to hydroponic growing than they are to gardens. Feel free to ask pointed questions.
Hopefully, this will make it through, but I'm copying it before I send, just in case. I learned my lesson when earlier I lost a post I'd spent more than an hour on. :-(
Hi Al,
Thanks so much for the detailed response from my Sep 13th post on the crushed granite and root pruning. I've continued my hunt for crushed granite in San Francisco. After a lot of searching I think I found a solution that may work but wanted to do a final double check with you.
The product is called "Desert Gold" and is sold in the 1/8" size. It is sold from Lyngso in Redwood City CA, a garden material retailer. I called them and they said desert gold was a crushed granite.
Here is a link to the description on their website. Do you think this would work? It sounds like it fits the requirements.
Also just curious, I know you always say 1/8" - 3/16" inch but what is the ideal size in a perfect world?
You're most welcome.
The desert gold material looks great. I wouldn't hesitate to give it a try. Hopefully, there's not a lot of material larger than 3/16.
In a perfect world, the grit particle size would be uniform at about .100 or 1/10". 3/32 - 5/32 is really really good. 3/23 -3/16 is really good. 3/32 - 7/32 is ok. 3/32-1/4 is getting a little large.
Speaking of which it would seem that you could screen both small and large particles out to get a uniform mix.
I've went ahead and constructed a sifter using aluminum insect screening to get the small particles out. Would you also recommend using a sifter to get the larger particles out? If so what material do you use? In one of the images earlier in the thread (June 16) it looks like you have several different sifters.
Also, just curious but when you are giving measurements are you defining the height, width and depth? I.e. a perfect particle size would be 1/10" high, wide and deep? What about a particle that is 1/10" high and deep but 1/2" wide? It seems that a lot pieces of the bark also fall into this category where they are longer or flatter.
I use hardware cloth of various sizes as the mesh through which I screen soil ingredients. If the particles happen to be inappropriately large, I would screen to remove them. When I describe materials, it would be materials that would fit through screening material of that size.
Hi Al
Thank you for your advice on Thu,Sept.16 at 22:41
in response to my post on sept.16 at 17:30.
As far as fertilizers, I would like to experiment with the Foliage-Pro 9-3-6 (since you've had so much success with it)by using it on half the tomato plants and the combination of fertilizers(the 5-10-15 plus the 30-10-10 you suggested I mix) on the other half. By the way, the 5-10-15 is a CRF (controlled release fertilizer). Are Crf's usually mixed in just the upper one inch in a containerized plant?
If I may ask, where's the best price you've found to purchase the Foliage-Pro 9-3-6?
CRFs can be incorporated OR broadcast on the surface, but because temperature has primary influence on release rates, they work better in containers when incorporated. I would try adding 1/2 tbsp or 2 tsp per gallon of soil when you make it, and then fertilize with the 30-10-10 as required to keep the foliage nicely green and see how that goes.
I just bought 2 gallons of FP from a wholesale supplier in a MI city where I was attending a MABA bonsai convention. They're a wholesale outfit & only sell to entities that have established commercial accounts, so I don't know who might have the best price. I paid $36.50/gallon. I used to buy it from Oakhill Gardens in Dundee, IL, an orchid supply house, but the last time I inquired they were out. I think I paid about $30/gal from them when I last bought it, but that was a couple of years ago & you KNOW things aren't getting cheaper! ;o) Good luck - and DO let us know how you fare. .... always interested in hearing of your successes or observations.
I just purchased FP 9-3-6 from New Harvest Hydroponics in Calistoga for 17.95 a quart. Since I haven't been able to find it anywhere else I don't know about the price comparison except on line, which is cheaper until you add shipping and then it gets really pricey. Good luck!
entities that have established commercial accounts>>>>>
Hi Al,
I need your help again. I was inquiring around to find a nursery who carried the foliage pro 9-3-6. No one seemed to carry it locally...only on line. I mentioned to one local nursery that someone(you of course) on the garden forum purchased it for wholesale at an MABA Bonsai convention but that you had to have an established commercial account with them to purchase it. The nursery informed me if I got the name of the company wholesaling FP, that she could try to contact them and purchase it for me, of course with a slight cost increase for her profit.
Al, do you remember the name of the company you bought it from?
Thank you.
Take care.
I have a question about ph testing kits/meters and soil testing kits. Since you've been at this a way lot longer than I have, which one/s do you recommend or deem reliable and durable for someone who's going to be gardening seriously.
There are so many out there at garden stores and on line. Some are very expensive while less expensive ones have mixed reviews. I trust your opinion.
Jon - it was 'Commerce Corporation' (Formerly Mollema & Son) in Grand Rapids, MI. I buy many hard to find supplies from them. Try Oakhill Gardens, too. They might have resupplied since I last tried them for 9-3-6.
I would ask the pH/soil testing question on the Hydroponics Forum if no one here steps up with an answer. I really don't worry at all about pH, other than to use common sense in my choice of Ca sources and to add some vinegar to my irrigation water (usually in winter - stuff I'm over-wintering indoors under lights) when I see signs of pH induced Fe deficiency. Any testing I've done on soils & such to get an idea of their pH was done using equipment belonging to a botanic garden near me, where I spend a fair amount of time, so I'm not going to be much help. Sorry.
Hi Al,
I'm trying to make your basic bark mix, but can't find bark sold in my area. I've checked all the big stores I know of in my area, but all they have is bark mulch. Would that work or is it too overprocessed? Is there any any particular type you would recommend? Thanks a lot,
It's sometimes difficult to find, Elberth; but it's a well-covered topic. You can do a search of this forum - there are several threads that address the issue, at least one of them being on the front forum page as I write.
Good luck.
Hi Al,
So I've done the treasure hunt and have successfully obtained all the ingredients for the Gritty mix (that took a lot of time, research and patience!). I'm ready to move on to the screening stage and had a quick question.
I'm constructing two screens to filter out the large and small particles. For the large particles I'm using a 1/4" screen. For the small particles, this is where I have the question.
I've scoured through the historical threads and it looks like ideally you are trying to get particle sizes in the 1/8" to 1/4" range to achieve a homogenous mix. With this said it would seem that ideally you would use a 1/8" screen for the small particles.
However, it looks like you are recommending using insect screen or even #10 screen (10 screens per square inch) which I believe are both smaller, tighter screens which might result in some small particles (1/16") staying in the overall mix.
So if you were going for the ideal mix would you use a 1/8" screen for the small particles or go with the #10 or insect screen?
Here is previous post of yours on the topic of particle size
"Tapla - 2) When you make the gritty mix, the two ingredients that are closest in size are going to have the most significant impact on drainage and whether or not the soil holds perched water. What works very well for me is usually the equal parts mix with the screened Turface being the smallest of the components, followed by the granite, which I estimate is about 50% larger than the Turface, and then the bark (largest) in 1/8-1/4" size. Most of the bark is concentrated more toward the 1/4" size. I estimate the sizes to be about 1/16-5/32 Turface, 1/8-3/16 grit, 1/8-1/4 bark. I would prefer the Turface was just a fraction larger and the grit a fraction smaller, but that's how it goes. ;o)
No matter which way you head on particle size, you'll be OK in the aeration/drainage dept - as long as you don't get TOO small, and you can always adjust water retention by +/- the Turface and grit. What you DO need to guard against is a size differential so disparate that the materials want to separate."
Thanks in advance. Your advice has been invaluable! I'm excited to start the process of moving 50 containers over to the new mix (over time)!
Gritty Mix Ingredients: Bay Area, San Francisco, Oakland, San Jose
For those in the bay area (San Francisco, Oakland, San Jose) that are embarking on the quest to source ingredients for the Gritty Mix here is what I have come up with.
Let me preface this with, after much, much searching I have found the easiest way to source the ingredients, no matter where you are, is to call the manufacturer directly of the product you are looking for and ask if any retailers in your area carry it. This works much better than randomly calling the garden/landscape/feed/roofing retailers who will often have no idea what you are talking about. Also you have to be willing to devote some time to this and drive a little.
- Ewing Landscape & Irrigation Supplies (San Francisco)
- 1618 Jerrold Ave, San Francisco, CA 94124-2135, 415-695-9530
- http://www.ewing1.com/general/ews_locationmap.html?branch=86
- Around $13 per 50 pound bag.
- Lyngso Garden Materials
- 19 Seaport Blvd, Redwood City, CA 94063, 650.364.1730
- http://www.lyngsogarden.com/
- What you want is the "1/8" Desert Gold (which is crushed granite).
- Al has verified that this will work in a previous post.
- Notes, this is a bigger landscaping supply store. You have to bag it yourself out of a big pile but it isn't too hard.
- $5 per bag which is about 100 pounds.
- In Al's notes he refers to this as Gran-I-Grit (grower size) or #2 cherrystone.
- For this product you can either go the chicken feed route (feed & grain stores), the roofing gravel route (roofing suppliers) or the lanscape supply route (crushed granite).
- In a prevous post of Al's he talked about how Shasta Forest Products was one of the large manufacturers in our area for fir bark. They sell 3 cu ft bags of fir bark in the perfect size "1/8" - 1/4")
- http://shastabark.com/products.htm
- I called Shasta and they told me Nurseymen's Exchange in half moon bay carried the product.
- Nurseymen's Exhange (2651 North Cabrillo Highway, Half Moon Bay, CA 94019, 650-726-6361)
- http://www.bloomrite.com/
- 3' Orchid Bark (1/8" - 1/4") (Mini)
- Note, Nurseymen's Exhange is a massive complex, when you pull in go up a little and to the right and park in the customer parking section. I think this place is for wholesalers but they did sell me.
- 3 cu feet for $15 each.
For all these places I would definitely call ahead and confirm they have the product in stock. Good luck and happy hunting. You _can_ find all these products, it just takes a little bit of time.
Kernul - the ideal mix would have the granite and Turface at .100-.125" (1/10-1/8), and the bark at .125-.167" (1/8-3/16). I screen the Turface through insect screen & use the fines elsewhere. You can get away with a fraction of the particles under .100" (which is approximately where the PWT disappears) if the other 2/3 of the mix is larger than .100". I like the bark a little on the large side to allow for breakdown (in particle size) over the course of 2-3 growth cycles.
Thanks Al. When I was searching for the crushed granite I ran across "decomposed" granite. Which the question then occured to me, will the crushed granite break down as well over time? It's weird as it is a rock and I don't imagine rocks breaking down that much as they aren't organic but then maybe I'm missing something.
Also will the Turface break down over time?
The reason decomposed granite exfoliates from bedrock is its high % of mica. As the mica absorbs moisture, it swells and 'blows' flakes of granite from the face of the rock. You won't have this issue to deal with when using Gran-I-Grit or cherrystone. Both granite and Turface are very stable. I used a fraction of Turface in my raised beds for bringing potential bonsai along when I built the soil more than 10 years ago, and I don't see any evidence it's breaking down - even after going through a number of MI winters.
Hi Al,
I've been away from the forum for a couple weeks for computer repairs.
Happy to say I finally have some Foliage Pro 9-3-6 and
Pro T-Kt which I hopefully will be using on my tomatoes after they are set into 15 gal. containers. The 5-1-1 mix with dolomite lime is prepared and I'm letting it marinate until planting. I am concerned though that the 20 tomato seedlings in starter containers have stopped growing >>> some at 3 inches while others at just one inch. They're not showing any sign of growth. I kept from over-watering or under-watering. Out of concern, I recently wet the top of the soil for each seedling with the diluted
Foliage Pro 9-3-6 a couple of times hoping to remedy the situation, but no change.
Maybe you could help shine a light on this issue, Al?
I would greatly appreciate it.
One of the first indicators of tight roots is stalled extension of branches/stems and weak growth; but I'm guessing, at 3" tall that's the not the issue. If you haven't fertilized previously, there is no reason you can't give the seedlings a full recommended strength dose of fertilizer. If you make sure they are getting good light (read full sun) and are warm enough - they should take right off. BTW - what kind of medium are they in now? ... keeping it damp, and not wet?
Hi Al,
I have the tomato seedlings in large dixie cups with holes for drainage and they are in the 5-1-1 mix...no dolomite yet. I have gave them a few doses of the pro 9-3-6 fertilzer over a period of 2 weeks when I saw no growth happening. There should have been enough of everything in the fertilizer to get them to a decent height of 6 inches before transplanting, but that's not the case so far.
I'm perplexed. Thank you Al for following up on this issue with me.
Kernul1, this is Santa Rosa CA checking in. I have called all around here and can't find either the Turface or the Crushed Granite, so I just may have to drive south and go to the places you mentioned. (I CAN find fir bark...whew).
Anyway, I just want to verify that you picked up and found both of those products as useful as you thought they were going to be before I trek 50+ miles for them....
Hi Al,
With all the ingredients in hand, I've started the sifting process and had a few questions. I'm trying to swap out 50 containers worth of soil so I'd prefer to do this in the most efficient way.
I am using a 9x9 hardware cloth (.088" openings) to filter the fines. Here are the three ingredients I was able to source:
1) Shasta: Orchid Fir Bark: (1/8" - 1/4")
2) Turface MVP
3) 1/8" Crushed Granite (Desert Gold)
1) It seems like it takes a decent amount of time to screen out the fines for one container. I also have constructed two other screens to be used to filter out the larger particles (a 1/4" for the large fir bark and a 9x9 (.1387") for the larger turface/granite).
I'm assuming that at the end of the day it is more important to screen out the fines then to screen out the few larger pieces which may be in the mix. Would this be correct? I'm just trying to save some time and there doesn't seem to be that many larger pieces in the mixes.
2) Do you usually rinse out the mixes before you combine them? Does this help get additional dust/fines out?
3) What do you do with all the fines/dust that you sift out? If you are screening out larger pieces what do you with them?
Thanks so much in advance. Your advice and guidance have been invaluable.
I would screen everything over the .088 and call it good - unless there is a wide size disparity in the granite (the 2 products I use are screened so the size is very uniform). Screening the bark and granite is just to remove the dust, while screening the Turface removes what would be too high a % of fines.
I don't often rinse, but it would remove additional dust. The reason I don't is because I usually make large batches & I don't want a wet screen or to clog my screen with dust mud as I move to the next batch.
I toss bark fines on the gardens/beds and use the fines from Turface in my raised beds or in hypertufa projects in place of sand. I don't get enough dust from the granite to even think about - it just settles on the lawn where I do my screening.
Well... here we are, coming to the end of yet another "Container Soils - Water Movement and Retention" thread... the next will be number 11, I believe! Wow! When I first read this article, I believe we were at or around number 7.
This has proved to be a very popular thread with a very important article! For me, it's the base of where it all begins for container grown plants. It's the "why" and the "how" explained so simple and beautifully. It's the beginning of my success as a container gardener, and I'm certain I'm not the only one!
I not only look forward to many more new articles and information from Al, but I also look forward to seeing this one carried forward to number 11... and 12... and so on!
Congratulations, Al, on your continued success as a knowledgeable and popular teacher!
I remain your humble student, and your good friend. :-)