Container Soils - Water Movement & Retention V

15 years ago

A thread similar to this has been posted four other times. Each of the other postings have reached the maximum allowable - 150 replies. I would like to preface this post by saying that over the last few years, the thread & subject has garnered a fair amount of attention, evidenced by the many, many e-mails I find in my in-box, and has been a wonderful catalyst in the forging of new friendships and in increasing my list of acquaintances with similar growing interests. I welcome these individual exchanges, which alone are enough to make me hope the subject continues to pique interest and curiosity. Not an afterthought - I should add that there is equal satisfaction in the knowledge that some of the information provided in good-spirited exchange might be making a significant difference in some growers' success or satisfaction.

I'll provide links to the previous three threads at the end of what I have written. Thank you for looking into this subject - I hope that any/all who read it take something interesting and helpful from it. I know it's long, but I hope you find it worth the read.

Container Soils - Water Movement and Retention

A Discussion About Soilssize>

As container gardeners, our first priority should be to insure the soils we use are adequately aerated for the life of the planting, or in the case of perennial material (trees, shrubs, garden perennials), from repot to repot. Soil aeration/drainage is the most important consideration in any container planting. Soil is the foundation that all container plantings are built on, and aeration is the cornerstone of that foundation. Since aeration and drainage are inversely linked to soil particle size, it makes good sense to try to find and use soils or primary components with particles larger than peat. That components retain their structure for extended periods is also extremely important. Pine and some other types of conifer bark fit the bill nicely and Ill talk more about them later.

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

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

Consider this if you will:

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

There are two forces that cause water to move through soil - one is gravity, the other capillary action. Gravity needs little explanation, but for this writing I would like to note: Gravitational flow potential (GFP) is greater for water at the top of the container than it is for water at the bottom. I'll return to that later. Capillarity is a function of the natural forces of adhesion and cohesion. Adhesion is water's tendency to stick to solid objects like soil particles and the sides of the pot. Cohesion is the tendency for water to stick to itself. Cohesion is why we often find water in droplet form - because cohesion is at times stronger than adhesion, 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. It will stop rising when the GFP equals the capillary attraction of the fibers in the paper.

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

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

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

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

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

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

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

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

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

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

Note that there is no sand or compost in the soils I use. Sand, though it can improve drainage in some cases, reduces aeration by filling valuable macro-pores in soils. Unless sand particle size is fairly uniform and/or larger than about Â½ BB size I leave it out of soils. Compost is too unstable for me to consider using in soils. The small amount of micronutrients it supplies can easily be delivered by one or more of a number of chemical or organic sources.

My Basic Soil

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

5 parts pine bark fines

1 part sphagnum peat (not reed or sedge peat please)

1-2 parts perlite

garden lime (or gypsum in some cases)

controlled release fertilizer (if preferred)

micronutrient powder, other continued source of micronutrients, or fertilizer with all minors

Big batch:

2-3 cu ft pine bark fines

5 gallons peat

5 gallons perlite

2 cups dolomitic (garden) lime (or gypsum in some cases)

2 cups CRF (if preferred)

1/2 cup micronutrient powder (or other source of the minors)

Small batch:

3 gallons pine bark

1/2 gallon peat

1/2 gallon perlite

4 tbsp lime (or gypsum in some cases)

1/4 cup CRF

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

I have seen advice that some highly organic (practically speaking - almost all are highly organic) container soils are productive for up to 5 years or more. I disagree and will explain why if there is interest. Even if you were to substitute fir bark for pine bark in this recipe (and this recipe will long outlast any peat based soil) you should only expect a maximum of two to three years life before a repot is in order. Usually perennials, including trees (they're perennials too, you know) ;o) should be repotted more frequently to insure vigor closer to their genetic potential. If a soil is desired that will retain structure for long periods, we need to look more to inorganic components. Some examples are crushed granite, pea stone, coarse sand (see above - usually no smaller than Â½ BB size in containers, please), Haydite, lava rock (pumice), Turface or Schultz soil conditioner, and others.

Thank you for your interest.

Al Fassezke

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

Featured Answer

justaguy2

15 years ago

last modified: 8 years ago

Very interesting Al, thank you for the response. I have been considering growing outdoors in pure turface (most indoor growing is done in pure Hydroton (hydroculture)), but was hoping for an idea of the material you were growing well in such a medium out of doors as well.

I can't really say enough about the great information you have provided in these threads and on this forum over the years. You have taken on more than one sacred cow and you never make any claims you can't back up with solid science.

Here is a toast to a very long running thread (with good reason) started and maintained by a guy with a passion for detail and sound science. Keep it up! (no pressure ;-)

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Comments (150)

lilfrenchgardener
14 years ago
last modified: 8 years ago
Thanks Al. I agree with a post above - you should write a book :)
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
You guys are way too kind. Thank you, though - sending well wishes for a good weekend.

Al
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Hi, rina. I know wood chips are different than bark, but I saw a nursery that was using these mixed with some alder saw dust. In about a year it turned to this incredible black, rich "soil". The guy as the nursery said it breaks down better and more nutritious for the soil and depletes less nitrogen in the process. The wood chips I was seeking are about the size of medium bark in nurseries. In retrospect, I am glad I didn't try that. Works great outdoors, not sure about containers! The black bark is essentially composted evergreen tree bark. I say evergreen because it could be a mix of a number of different types here in the Pacific NW --- hemlock, fir, ceder, spruce, etc. I didn't screen it, it seemed plenty loose initially; small to medium size in comparison to bagged nursery store bark. It would have been o.k. had I added the peat and perlite per the formulas given here. Screening would have left just the larger pieces, but that would be quite a chore for the volume I was using! I repotted some of the plants using the 5:1:1 formula with my black bark and those are doing much, much, better. A gardening friend said "Think of it...bark is like big saw dust. If you pack it down it gets as hard as a board". That is essentially what happened when I used the black bark alone without the the perlite and moss. ;(
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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") http://shastabark.com/products.htm 2) Turface MVP 3) 1/8" Crushed Granite (Desert Gold) http://www.lyngsogarden.com/index.cfm?event=Display.Home.Product.Group&homeCategory=STONE&categoryid=1094&productgroup=PEBCOB&groupname=Pebbles%252C%2520Cobbles%2520%2526%2520%2520Colored%2520Gravel Questions: 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. Best, Kernul1
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rogue64
14 years ago
last modified: 8 years ago
Greetings Al,

I think my previous post fell through a crack. Either that or it was too long (it was a bit wordy ;). In either event, I went ahead, mixed up a batch of 5-1-1, and repotted the smaller Croton. I bare rooted the cuttings and replanted 3 of them in 4" terra cotta pots. Naturally, I have more questions (who'd have thought? :D).

The first thing I noticed was watering. After 1 day the soil is "damp". After 2 days it's dry-but-cool. These plants are supposed to be kept "lightly moist". Is dry-but-cool the right time to water for this mix? BTW, it *does* seem easier for me to gage moisture levels by sticking my finger in *this* mix.

Second question: What is the purpose/function of the peat in the mix? It's finer than the 1/8" or larger particle size which seems to be your general goal for a well draining soil.

Third question: The Pine Bark Fines I bought were from a Bonsai supplier. They look exactly like your "partially composted bark" picture. Looking closer i noticed that some of the particles were less than the specified 1/8" size. I'm currently drying some out for screening but I'm guessing that 5% (or less) will fit through an insect screen and (maybe) 20-25% will fit through a 1/8" screen. Given that, would these particles replace the function of the peat (use them instead of peat) or are they part of "good" pine bark fines?

Fourth Question: Not really on topic, sorry about that. Somewhere in all the posts you've made you suggested 2 books on Root Pruning (or something like that). I have no idea where I read it but I'd appreciate it if you could post the titles and authors again.

Thanks for all your help!

Regards,
Tim :)
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Is dry-but-cool the right time to water for this mix?

That's a good time, yes. The soils I describe here are very forgiving of heavy-handed watering if/when it does occur. I suppose the technical answer would be that you should water when the soil is at the lowest water retention level it can have w/o causing drought stress, but I realize it's pretty impractical to offer that in the way of advice. Still, I think you probably have a fair amount of reserve water in the soil when it first feels cool/dry to you. You could always withhold water while watching carefully for the first signs of wilt (after the plantings are established) to get a better idea of whether you can/should wait another day or two before watering.

I often post this:
In a workshop conducted by bonsai master Ben Oki, one of the other participants asked, "How often should I water this juniper, Mr. Oki"?
His reply, in broken English: "Wait until plant become completely dry - then water day before."

I never did figure out if he was serious or not, but the advice was so very sage. His eyes were twinkling, but he had a straight face, so go figure.color>

What is the purpose/function of the peat in the mix? It's finer than the 1/8" or larger particle size which seems to be your general goal for a well draining soil.

Well, the peat can be eliminated in most cases if you're familiar with a little soil science and the bark particles are very fine. The primary functions of the peat are additional water retention and to help keep pre-liming medium pH low enough that the addition of the liming agent doesn't push pH out of the favored range of 6.0 - 6.5. I try to limit the addition of all fine particulates (over and above those in the bark) to The Pine Bark Fines I bought were from a Bonsai supplier. They look exactly like your "partially composted bark" picture. Looking closer i noticed that some of the particles were less than the specified 1/8" size. I'm currently drying some out for screening but I'm guessing that 5% (or less) will fit through an insect screen and (maybe) 20-25% will fit through a 1/8" screen. Given that, would these particles replace the function of the peat (use them instead of peat) or are they part of "good" pine bark fines?

Partially covered above. Just use them as is if you're using the 5:1:1 mix as the basic formula. If you're using the gritty mix to extend service life of the soil & extend the interval between repots, you would probably want to screen it or look for an uncomposted product with larger particles. I use two types of pine bark + screened fir bark for my soils, depending on the intended use.

. . . you suggested 2 books on Root Pruning (or something like that). I have no idea where I read it but I'd appreciate it if you could post the titles and authors again.

I don't remember suggesting anything on root pruning in particular, but most good books on bonsai will cover it in some detail. If you let me know if you're more interested in physiology or soil science, I'd be glad to suggest a few texts that I often refer to for confirmation of the accuracy of what I offer here.

Some good ones:

Physiology of Woody Plants * Kozlowski & Pallardy (second edition) ISBN# 0-12-424162-x (a superb text)
Growth Control in Woody Plants * Same authors ISBN# 0-12-424210-3

Plant Production in Containers II * C. Whitcomb Ph.D. ISBN#0-9613109-6-0

A New Tree Biology * Alex Shigo Ph.D. ISBN# 0-943563-04-6

Al
rogue64
14 years ago
last modified: 8 years ago
Greetings Al,

Thanks for the prompt reply! I cut, pasted, and sniped the relevant portions of it for my reply:

*** Is dry-but-cool the right time to water for this mix?

That's a good time, yes...

I often post this:
In a workshop conducted by bonsai master Ben Oki, one of the other participants asked, "How often should I water this juniper, Mr. Oki"?
His reply, in broken English: "Wait until plant become completely dry - then water day before."

I never did figure out if he was serious or not, but the advice was so very sage. His eyes were twinkling, but he had a straight face, so go figure.***

I do seem to recall seeing this a time or 6. Unfortunately, I misplaced my Time Machine. :D I suspect what he was saying, in a properly enigmatic fashion, is that each plant is different. You have to figure it out for yourself. I was looking for a "safe zone" to start with and Dry/Cool seems to be it. Ill tinker more later as I learn.

*** What is the purpose/function of the peat in the mix? It's finer than the 1/8" or larger particle size which seems to be your general goal for a well draining soil.

Well, the peat can be eliminated in most cases if you're familiar with a little soil science and the bark particles are very fine. The primary functions of the peat are additional water retention and to help keep pre-liming medium pH low enough that the addition of the liming agent doesn't push pH out of the favored range of 6.0 - 6.5. I try to limit the addition of all fine particulates (over and above those in the bark) to I thought of the water retention. I didnt think about pH though. Even with fine bark particles it looks like Im better off sticking to the base recipe for now. The bark Im going to screen is for information purposes I guess. I can experiment more later as I learn. Hmm... Seems Ive said that before. ;)

***. . . you suggested 2 books on Root Pruning (or something like that). I have no idea where I read it but I'd appreciate it if you could post the titles and authors again.

I don't remember suggesting anything on root pruning in particular, but most good books on bonsai will cover it in some detail. If you let me know if you're more interested in physiology or soil science, I'd be glad to suggest a few texts that I often refer to for confirmation of the accuracy of what I offer here.

Some good ones:***

I think Im probably looking for the physiology side. Im interested in the hows, whys, and wherefores of the process. Im also interested in 1) Seeing how long I can keep the Crotons (and similar plants) alive and 2) Seeing if I can stop or slow growth at a specific height. No reason for it beyond curiosity, house plants are cheap. Unless you can think of something specific, the books you listed are probably a good start and the Bonsai Forum will likely have additional suggestions of good bonsai books in past posts.

Thanks again for your response. Ive learned a lot on this forum and Im having loads of fun watching my plants grow. :)

Regards,
Tim :)

P.S. The Italics and Bold from my word processor didn't come through. GRRR!!!! Sorry about that.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
I have made up a little tutorial illustrating how to make modifications within the GW text box, so if you or anyone else following the thread wants to know how to do italics, bold text, underline, strike through, changecolor> fontcolor> colorcolor>, or insert an imbedded link in the GW text boxes, just send me an email & I'll forward. For clarity, it has active links and illustrations that make it difficult to share in a GW text box.

Al
katskan41
14 years ago
last modified: 8 years ago
I would like to publicly thank Al for sharing this outstanding information with the gardening community. His advice has helped us all grow some very healthy plants in containers. Without his guidance I'd still be buying commercial potting mixes and wondering why my conifer seedlings were growing so poorly.

Thanks Al!

Regards,

Dave
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
You're too kind. Thank you, Dave.

Al
katskan41
14 years ago
last modified: 8 years ago
Good morning Al.

I had yesterday off from work and took the time to catch up on your many posts on GW. I hope you realize how helpful and informational your posts are. I have no doubt that you could easily write an excellent reference book on garden soils and container gardening. I've learned much from your posts and emails. =)

After reading most of your recent posts I do have a couple of questions for you.

I'm growing conifer (fir, pine and spruce) seedlings, all are age 3 years and younger, outdoors in plastic containers using equal parts of the pine bark/Turface/granite soil mixture. My goal is to grow the best trees from seed that I can and plant them in our backyard once they are large enough and have a strong root system. The seedlings currently receive about 8 hours of direct eastern sun a day and are protected from strong western winds and hot afternoon sun. They stay outside all winter and recieve snow cover. I generally water the spruces and firs every other day (daily during very hot weather) and the pines every third day (every other day during hot weather) until saturated, making sure excess water runs out the drainage holes to help remove salts and promote gas exchange. Our well water is high in iron (visible rust) but I do not know the actual mineral content of the water. I fertilize with normal strength (1 tbsp per gallon) fertilizers, alternating MG granular 24-8-16 or Miracid 30-10-10 once a week except during very hot (85F or above) weather.

With that background, here are my questions.

Question: Do you still use Miracle-Gro liquid 12-4-8 w/micronutrients as your "standard" fertilizer or have you switched to something else? In several later posts you mentioned Foliage-Pro 9-3-6 as a possible replacement since it's a 3-1-2 ratio of majors and contains all the minors as well. I'd prefer using a single 3-1-2 fertilizer that contains all the majors and minors in the correct amounts. Keep things simple I say. =)

Question: As mentioned I generally water the trees every two or three days, depending on weather and tree type, and fertilize once per week at full strength. Since I have only a few trees I generally mix a gallon of fertilizer at a time. Should I be applying a very weak (1/4 or 1/8th strength) fertilizer solution each time I water to avoid over-fertilizing (I believe you call this "Weakly weekly" fertilizing) or continue weekly feedings with full-strength fertilizer?

Question: You mentioned adding hydrogen peroxide (H2O2) when watering to increase oxygen levels. Would this benefit all container-based plants, including conifers? If so, how much should I user per gallon of water? Also, if I add the H2O2 to my fertilizer solution (either full-strength or weak strength) will it cause any chemical problems/reactions when mixed in with the fertilizer?

Question: Based on your suggestion I plan to add gypsum when mixing new soil batches. I believe you said to use 1 tbsp of gypsum per gallon of pine bark/Turface/granite soil mixture, correct? Is this still your recommendation?

Thanks for taking the time Al. Your wisdom is much appreciated!

Regards,

Dave
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Question: Do you still use Miracle-Gro liquid 12-4-8 w/micronutrients as your "standard" fertilizer or have you switched to something else? In several later posts you mentioned Foliage-Pro 9-3-6 as a possible replacement since it's a 3-1-2 ratio of majors and contains all the minors as well. I'd prefer using a single 3-1-2 fertilizer that contains all the majors and minors in the correct amounts. Keep things simple I say.

Often, what I suggest and what I actually do are different. Sometimes, that's so I can keep it simple here, and sometimes it's because some of the things I use aren't readily available to the hobbyist.

I bought a gallon of Foliage-Pro 9-3-6 this year and I've used about half of it. I haven't noticed any amazing results or problems, but there's probably a good reason for that. I was using the MG 12-4-8 regularly, but adding STEM to it to use on the older plantings, and using it w/o STEM on new plantings/repots that had Micromax included in the soil. IOW, no matter what, the plants were always getting a full compliment of the essential nutrients. For that reason, I wouldn't expect much difference between the MG and the FP, but you and others might. The FP has most of its N in nitrate form, but I don't fertilize when the mean temperature is running cold (80*), so that's not a huge advantage either. I was excited for YOU guys, about the FP, simply because it offered a really nice package. A really good ratio, N in nitrate form, the secondary majors (especially Ca & Mg), and all the minors ..... everything a plant could want.

I think there's an answer to your question in there somewhere. ;o)

Question: As mentioned I generally water the trees every two or three days, depending on weather and tree type, and fertilize once per week at full strength. Since I have only a few trees I generally mix a gallon of fertilizer at a time. Should I be applying a very weak (1/4 or 1/8th strength) fertilizer solution each time I water to avoid over-fertilizing (I believe you call this "Weakly weekly" fertilizing) or continue weekly feedings with full-strength fertilizer?

So you're fertilizing full strength every second or third time you water ...... This pretty much assures that the trees are receiving a constant supply of nutrients, at luxury levels and higher. That probably isn't the best situation. It can cause weak, succulent growth, and whenever nutrient levels drop to adequacy levels, nutrient deficiency symptoms are likely to occur. I think you could produce a happier crop by either fertilizing at 1/2 strength weekly, 1/4 strength at every watering when temperatures are within the parameters mentioned above, or full strength every two weeks. Keep in mind, that the higher the solution strength, the more difficult it is for plants to absorb water and the nutrients therein.

Question: You mentioned adding hydrogen peroxide (H2O2) when watering to increase oxygen levels. Would this benefit all container-based plants, including conifers? If so, how much should I user per gallon of water? Also, if I add the H2O2 to my fertilizer solution (either full-strength or weak strength) will it cause any chemical problems/reactions when mixed in with the fertilizer?

There is nothing to worry about chemically speaking (within reason). H2O2 has an extra O atom (compared to H2O) in an unstable arrangement. Since H2O2 is an unstable molecule, it breaks down easily. When it does, a single O- atom and a molecule of water is released. This O- atom is extremely reactive and will quickly attach itself to either another O- atom forming stable O2, or attack the nearest organic molecule.

I've found it useful to add H2O2 to irrigation water when I've been lazy about being sure I have no plants in compacted soil - especially over the winter. These plants seem to get substantial benefit from the extra O2. In the highly aerated soils I know you're using, I really don't see much benefit in using it. If you DO feel the urge to use it:
1 cup, add 1-1/2 teaspoons ....... 35% - 7 to 10 drops
1 quart, add 2 tablespoons ...... 35% - 1/2 teaspoon
1 gallon, add 1/2 cup .............. 35% - 2 teaspoons
5 gallons, add 2-1/2 cups ........ 35% - 3 tablespoons plus 1 teaspoon
10 gallons, add 5 cups ........... 35% - 6 tablespoons plus 2 teaspoons
20 gallons, add 10 cups .......... 35% - 3/4 cup plus 1 tablespoon plus 1 teaspoon

Question: Based on your suggestion I plan to add gypsum when mixing new soil batches. I believe you said to use 1 tbsp of gypsum per gallon of pine bark/Turface/granite soil mixture, correct? Is this still your recommendation?

Yes it is, for the gritty, 2/3 inorganic mix. When you do use gypsum, it's important that you include 1/8 - 1/4 tsp Epsom salts in your fertilizer each time you fertilize. If you decide to go to the FP 9-6-3, you can forget about adding either gypsum or dolomitic lime to soils. Also, if you don't add gypsum, leave out the Mg supplement (Epsom salts).

Good luck, Dave.

Al
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Ohh - I almost forgot ...... maybe JaG will offer comments/evaluation re. the FP 9-3-6. I know he's using it, too.

Al
katskan41
14 years ago
last modified: 8 years ago
Al,

Thanks so much for taking the time to respond to my many questions. I've learned a great deal from this thread and the many posts in it.

I'll look for a local source for the Foliage-Pro 9-3-6. If I can't find one I may have to mail order it. Big box stores won't have it I'm sure. Sounds like it's the perfect "all-in-one" fertilizer for what I'm doing.

Speaking of "big box stores", our local Meijer had many of their mulches on clearance, including bags of pine bark mini nuggets, the kind used in the 2/3 inorganic soil mix. If anyone needs to buy bags of pine bark for soils this might be a good time to check out your local suppliers and stock up.

Thanks again Al.

Regards,

Dave
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
I'm guessing you can probably save yourself some tracks & go directly to the net. It's pretty unlikely you'll find it at a conventional retail establishment in MI. Puglvr had found it at a very good (half) price from the bonsaimonk.com e-store, but the last time I checked for a friend, it looked like perhaps they'd sold out. It might be worth sending them an email to check?

Al
justaguy2
14 years ago
last modified: 8 years ago
Ohh - I almost forgot ...... maybe JaG will offer comments/evaluation re. the FP 9-3-6. I know he's using it, too

I like it. How is that for a comment? :) This year I am not using any CRF in containers, nor am I using any fert besides FP 9-3-6 and Pro Tekt 0-0-3.

It is difficult to evaluate plant performance relative to prior years because this year with all the rain and cool weather has some plant types 2-3 weeks behind their normal schedule.

Having said that I have absolutely no disease issues (knock on wood) on any plants and typically I would have at least some powdery mildew on zinnia/dahlia/cukes etc. Is it the Pro Tekt's silicon? Subsequent years will tell.

Based upon plant performance thus far I am not tempted to switch away from FP and PT toward anything else.

There have also been no signs of nutrient deficiency in any plants other than a few citrus I have no experience with and just got this spring. They arrived showing the signs of deficiency and are just now clearing up. I would guess it has more to do with the weather now being warm and dry than anything else.

Do I think FP is 'the bomb'? No, but I do think it is a terrific product and it is a complete fertilizer so no need to worry about how to get this or that nutrient to the plant. It is a one stop solution for most plants.

I need to do more testing next year to determine if boosting the K with PT really matters to any plant(like tomatos). Based upon using FP alone with flowering, ornamental plants as well as combining the 2 products (different containers) I am not seeing a reduction in blooms when using just the FP 9-3-6. It could well be that FP 9-3-6 is a one stop fert even for veggies known to not produce well when given too much N, but I need to test/confirm that next year. I was too chicken to do it this year with my maters :)
katskan41
14 years ago
last modified: 8 years ago
Thanks JAG and Al. I think I will try that FP 9-3-6 next growing season. Can't find it locally, especially this time of year, so I'll have to mail order some. Sounds like the Pro Tekt might be a good purchase as well.

For hobbyists like me it will be good to use only 1 fertilizer, rather than using MG 12-4-8 and add gypsum and epsom salts. Keep it simple, that's my motto! =)

BTW, I did notice something interesting. I'm growing some white pine seedlings in Al's container mix (pine bark/Turface/granite) and I noticed that the seedlings in those containers are significantly larger and healthier looking than the ones just planted in regular potting soil. The needles are much heavier and thicker on the container-grown seedlings than the leftover seedlings in the regular potting soil.

Thanks!

Dave
suseart
14 years ago
last modified: 8 years ago
Al,

I am a newer reader of the GW forum, and I just wanted to thank you for the invaluable information on soils. After spending the last couple hours reading this and other threads of yours, I feel like I have become more educated about soils and nutrients.

After copious note taking, and toying with the idea of printing out, three hole punching and filling binders with everything I can find that you have written, it occurred to me that I wish you had already written a book I could order. Then I read Dave's post and saw that I wasn't the only one to think of this. I hope you are working on one now, otherwise I have a lot of printing to do.

Thanks so much,
Susan
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Thank you, Susan. You're so kind to go out of your way to say something so nice. No plans for a book at this point, but I will share that there is some pressure from friends, and I've received several offers of assistance if I ever decide to write. Perhaps in a few years, when I've retired ... I have a business, my gardens, and my little trees to babysit for now ..... and GW. All that, along with my familial and other misc. commitments, keeps me hopping. ;o)

Take good care.

Al
adamskj
14 years ago
last modified: 8 years ago
Al (or anyone else out there),

Have you ever tried using charcoal as your main soil ingredient? I've got a cheap source of bulk horticultural charcoal granules, and it seems like it would have similar properties to Turface & pine bark fines, with durability somewhere between the two.

I just put a jade into a pot made up with Al's soil recipe with charcoal instead of bark fines - wanted to know if anyone has any longer term experience with it.

Thanks,
Kevin
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
It's probably going to be physically more like perlite than anything else I can think of. I've used it from time to time, thinking that it had anti-fungal properties or somehow benefited the soil because it was a 'natural' ingredient. I'll leave you to your research in that dept, but I haven't found it useful as anything more than a soil ingredient that holds a little moisture and helps promote aeration when used in combination with similar size particulates. If it's free - no reason not to make use of it. ;o)

Al
lou_spicewood_tx
14 years ago
last modified: 8 years ago
It becomes a moot point with Smart Pot (fabric bag) in the ground. You can even use topsoil for it as long as its in the ground. I wouldn't recommend it for large sized. Much heavier. For example, if you want to plant out small seedlings but can't find a way to water it enough to keep the mix moist enough to keep it alive while it gets established, that's where 1g smart pot with topsoil (grown in the ground) comes handy...

Been there, done that. Much better success....
ryan_tree
14 years ago
last modified: 8 years ago
Would any of those mixes be good for, Oh, say a coast redwood tree? Mine needs to be repotted and am still lost on what to pot it up in. It was growing in basic seed starter, I think its time to take off the bib now. What would work? They love water, I know, but would any of the mixes mentioned work?
ed-claude
14 years ago
last modified: 8 years ago
tapla: If you decide to go to the FP 9-6-3, you can forget about adding either gypsum or dolomitic lime to soils.

Hi Al,

I am a wannabe container gardener (although I already have many pots full of mud with vegetable matter in them, some of it growing, some of it dying) and have pursued these soil threads furiously for the last couple of months in hopes of getting a handle on this beast. Like so many, I am hugely grateful for all the time you take to share you wisdom.

I must admit that some days I feel like I may be overwhelmed by "analysis paralysis." I think the time has come when I need to raise my hand and ask if you, justaguy2, or some of our other experienced hands can help me sort if out a bit. And so I launch myself as an eager beginner with a question about your comment above on FP and lime.

What is the connection? I have been quite concerned -- unduly so, probably -- to manage the pH in my containers. I would absolutely love to let go of this tedious piece of it. And merely by fertilizing with the FP, I can build soils with pine bark fines as the major constituent and forget about them being too acid for some plants?

Actually, a lot of my interest is toward acid-loving plants so I have also been concerned that even the bark-based soil might not be quite acid enough for, say, a potted azalea.

I am so hoping that you are going to tell me that the whole issue with acidity relates to the availability of other nutrients and FP is so miraculous that it feeds all plants properly under all pH conditions. But this seems too much to wish, even as we approach Christmas. Thanks!
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
I left a link on your other thread to read. Did you do the search for gritty mix?

The soil recipe in the original post above will work very well, but the gritty mix is more suited to woody material & will remain structurally sound longer.

Al
justaguy2
14 years ago
last modified: 8 years ago
I am so hoping that you are going to tell me that the whole issue with acidity relates to the availability of other nutrients and FP is so miraculous that it feeds all plants properly under all pH conditions. But this seems too much to wish, even as we approach Christmas.

Well, Merry Christmas! :)

The affect pH has on chemical reactions is complex and frankly beyond my present comprehension.

Al can probably give a better explanation that I can, but I will give it a try.

Plants do not care what pH the growing medium is because they don't use the growing medium for anything other than anchoring their roots. In a ground soil comprised largely of minerals that release nutrients we have to care about pH because it affects what nutrients will be released (made water soluble) and in what amounts. Too high a pH and certain nutrients are released in excess and others not enough and vice versa.

When using a high quality fertilizer such as those designed for hydroponics the nutrients are all formulated to be immediately available to plants in a reasonable ratio.

pH no longer governs what nutrients will be available in what amounts, what we put in the water does.

Commercial blueberry growers have long exploited a similar idea. Rather than worry about the pH of the soil the blueberries are growing in, they add sulfuric acid to the irrigation lines turning the irrigation water acidic. The water moves through the soil around the roots and 'liberates' nutrients in the ratio blueberries require because the water itself is the right pH even though the soil isn't. The acidic water doesn't really change the pH of the soil, but it doesn't have to. Until the acidity of the water is changed by the soil it liberates the nutrients from the soil as if the soil were the ideal pH.

Other growers who are forced to garden in alkaline soils have learned they can improve plant health by adding vinegar to irrigation water. Same idea as adding sulfuric acid, but vinegar is weaker and less dangerous to handle (not to mention more readily available for most people).

If you get the pH of the water right, the pH of the soil isn't as important because the water liberates the nutrients from the soil. If you get the nutrients in water soluble form into the water then pH largely becomes irrelevant as the chemical processes that liberate the nutrients from minerals doesn't have to take place at all.

I am certain I have oversimplified things and those with a better grasp of chemistry could do a better job, but this is how I understand it.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
EC - If a hobby container gardener tells you he/she is managing to manage pH in their containers, the odds are overwhelming that someone is not being honest, or at best, doesn't know what they are talking about. The management of pH is pretty technical and more often than not difficult for even commercial greenhouse/nursery operations with sophisticated equipment in place.

My suggestion is don't worry about it. You can try to steer media pH in a particular direction by using certain materials in your soils and water, but if you're using an appropriate fertilizer & you watch so the chemistry of your irrigation water doesn't present major problems, you should be fine. Spend the effort you'd use to worry about pH on learning something about soils or physiology & you'll have spent your time more wisely.

"And merely by fertilizing with the FP, I can build soils with pine bark fines as the major constituent and forget about them being too acid for some plants?"

You will probably want to add dolomitic lime to a primarily bark soil to nudge the pH closer to 6.0, but the quote you opened with came from a paragraph in which the discussion centered on the grittier soil I often use/suggest. It's pH is going to be somewhere around 6.0, which is very good for container soils. If you are using the 9-3-6 FP, it contains both Ca & Mg, so since none is necessary for either pH adjustment or mineral supplementation, you can leave it out (of the gritty mix when you use a fertilizer with Ca & Mg, which is uncommon, btw).

Al
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Thanks JaG - I was typing & didn't realize you'd posted.

Al
justaguy2
14 years ago
last modified: 8 years ago
Thanks JaG - I was typing & didn't realize you'd posted.

Thanks for your thanks :)

Normally I wouldn't respond to someone in a thread you started preferring you respond, but ed-claude mentioned me by name so I felt obligated.

So, ed-claude, I think you can consider both Al and I to be wishing you a Merry Christmas (and a happy New Year). Everyone else can too :)
ed-claude
14 years ago
last modified: 8 years ago
Al and justaguy,

You are an amazing tag team rescue squad for the horticulturally perplexed! It is much to the good fortune of all of us who browse these threads that your contributions are so complementary, with Al debunking so much conventional wisdom and bringing a fresh, scientifically-oriented approach to all our issues and justaguy doing the extremely useful follow-on of corralling, clarifying, and sometimes "simplifying," in the very best sense of that word. I like to have some access to what mother nature is doing behind the curtain, but, at the end of the day, I need to feel like I have a reasonable plan to go forward with.

I had really been fretting over pH, although I vaguely recollected Al somewhere discouraging trying to measure it. When you feel like you have no judgment or experience and are trying to get your arms around all these variables, it is almost irresistible to try to measure! Yesterday -- against Al's caution -- I had gone off the deep end was pretty committed to measuring pH, even though I realized some of the difficulties inherent in doing so.

These responses to my post put all this wonderfully in perspective. Now I can get out my vernier caliper (set to 1/8") and start obsessing again about the useful contributions I can make to the health of my plants. (Do you think the vernier caliper is sufficient or should I get out the micrometer? [grin])
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
No need to explain, JaG. Your input is always welcome. I don't mind the input of others on the threads I start, in fact I welcome it. It's only the 2 or 3 people who go to sometimes extraordinary effort to destroy the harmony and credibility of the few threads I've started that makes cause for discord. One queen troll in particular has been invited to leave GW well over a dozen times after posting under a new identity for each recurrence, yet she seems to always manage to turn up again, like a phoenix from the ashes, in attempt to sully any efforts I might have made. I'm glad the 99% of the remaining members are so rewarding to be around. ;o)

No need for such intricacies, EC. A yardstick is prolly all you/we/I need. ;o) Thanks for the kind words, too.

Al
Pat z6 MI
14 years ago
last modified: 8 years ago
Al, I have learned so much about soil from you and Butch Ragland in the Hosta, Container, and Houseplants Forums that thanking you for this free information hardly expresses my gratitude.
I just want to quickly say that because I may not always be ambitious enough to mix my own soil according to your recommendations, I think I am most approximating your recipe with a phaleanopsis orchid mix plus extra perlite. Do you agree?

Patricia Moore
Ypsilanti/Ann Arbor, Michigan
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Hi, Pat. If your middle name is Ann, it makes 6 the number of women I know named Patricia Ann. Two actually have the same last name as I - my mom and my wife are both Patricia Anns. ;o)

I appreciate the 'thank you'. It's very meaningful to me that you took the time to express your appreciation.

I'm sorry, but I can't answer your question about the soil for phals. My first thought is that it will be too porous, but w/o knowing the make-up, I can't say.

So it's an ambition thing, hmm? I'll make you a deal >>>>> Since you're almost a neighbor, you could bring a friend or significant other & drive up here to Bay City on a nice spring evening or weekend, and I'll help you make all the soil you need. I always have the materials on hand, and can accomplish making it with blazing speed ;o), so it wouldn't take long; and I'd charge nothing for my time - just what the materials cost me. I'd send it home with you all nice & neat in the bags the bark came in.

Take care.

Al
meyermike_1micha
14 years ago
last modified: 8 years ago
Al,
What about the equall parts of turface,pine bark, and granite?
I thought using no peat was better for house plants.
I though the slightest bit of peatmoss caused a perched water table.
That is what I am using. Above all I saw was mixes with peat moss. Everything I have planted now is in the Turface, Pinebark, and Granite with no peat. Was I suppose to use these soil mixes above with peat moss for my houseplants?
Will my mix of equall parts be just fine for all that is planted in it now without peatmoss over time? Thanks
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
You worry more than anyone I know, Mike. (I know Mike well enough to poke a friendly jab at him.) :o)

I started this thread in early spring of '05. Initially, there was lots of skepticism simply because of the fairly minor departure from a peat-based soil, along with the idea that (lack of) aeration was often instrumental in, if not the very root cause of, many of the cultural problems being discussed on the forum. Even though I'd been using one for years, it was only after some of the ideas I'd presented gained wider acceptance that was I able to introduce the idea that a container soil with a 2/3 inorganic component could be superior to the soil I'd been touting, and FAR superior to the long accepted standard of a peat based soil.

The two soils can be used interchangeably because their initial physically properties are nearly alike, but I've made the point over and over that it makes little sense to go to the extra expense to make/use the more durable 'gritty mix' when you're dealing with a short term planting when the recipe given above is entirely adequate.

"The slightest bit of peat" doesn't always cause a PWT, and a PWT isn't always a bad thing. At some stages in the life of a planting, a slight PWT that is managed properly can be looked at as an asset, extending the interval between irrigations w/o an appreciable negative impact on root function.

The reason I limit the peat content of the mix suggested in this thread to 1/8".

You have no reason to fret over the soil you are using. I use the 5:1:1 mix (recipe @ top of thread) extensively for plantings that are replaced annually (garden display containers, veggies, etc.), and fairly frequently for plantings in which the soil might be called on to serve for two years. For all the other plantings, including houseplants & most woody material, I use the bark:Turface:granite 'gritty mix' in equal volumes, or some minor variation thereof.

Al
meyermike_1micha
14 years ago
last modified: 8 years ago
Man I was so WORRIED I would have to put all my plants in the above soil ingrediants!!! Lol
Thanks Al for your time and explanation! Thanks
P.S..Al, I have actually plants in this mix above in smaller pots due to the fact they would dry out so fast in the gritty mix in pots 6 inches or smaller. But all my plants in pots bigger than 6 inches are in the gritty mix...Thanks alot!
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
"O thou of little faith, wherefore didst thou doubt?"

Scroll up to the picture in the OP (original post) of this thread & tell me what you see (as it relates to soils). ;o)

Al
ltruett
14 years ago
last modified: 8 years ago
Al,

I am currently using a chipper/shredder machine to grind up pine bark nuggets. So far it has worked well but my question is, how much of a detriment is it to used pieces ranging from 1/8 to 1/2 inch instead of 1/4 inch. It would save me some time as far as screening out the larger pieces. I am planning to use the mix in 1g pots for trees.

Is there any use for pieces from 1/16 to 1/8 such as germinating seed in small pots/cells before repotting them into 1g pots?

Thanks.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Actually, the larger pieces are more appropriate for seed germination, as seedlings respond VERY favorably to max aeration.

There is no reason you can't use bark with a few 1/2" pieces in it, but if a significant portion of it is comprised of pieces that large, you'll need to shoulder the responsibility of watering more often.

In a perfect world, our soils (ok - MY soils then) ;o) would be comprised entirely of absorbent, 3/32 - 1/8" particles. This guarantees maximum water retention with NO perched water. That's too much work & expense for me to screen everything & toss what doesn't fit such a narrow spec, but I still try my best within reason to keep the bulk of the material I use in that range, but experiment if you like.

Dry bark screens through a 3/8 inch screen very quickly. I have 2 sets of soil screens. 1 set is about 16 x 16 and is made of 1x2s with insect screen on one, then 1/8, 1/4, 3/8, and 1/2" hardware cloth on the others. The other screens are the same mesh, but are 24 x 24 and made from 1x4s. I can screen a 2 cu ft bag of bark through a 3/8 screen in 5 minutes or less. If I was using a chipper, I'd simply run the large pieces through again.

Maybe I've been lucky, but every year, I find at least 3 or 4 sources of suitable bark. A couple are usually fine & partially composted (I went through 70+ 3 cu ft bags of it, mulching the gardens this year, + what I used for container soils). I usually always find a couple of sources for uncomposted bark that is quite fine. Even though the size of the particles is less important in the gritty mix, I'll still screen out the stuff larger than 3/8.

I guess my point in all this is Keep your eyes open and don't think that just because you found 'pine bark' it's the only bark on the market. ;o)

Good luck.

Merry Christmas.

Al
ltruett
14 years ago
last modified: 8 years ago
Thank you Al.

So far all I have been able to find is a landscape mix or soil conditioner mix and it seems like I lose 25% of the bag after filtering out the small particles and would lose another 25% filtering out pieces larger than 1/4 inch.
After running a bag of nuggets through the shredder probably 90% fits through the 1/2 inch opening. Of that a little more than 50% fits through 1/4 opening. I have still yet to filter out the small stuff as I am trying to find some 1/8 mesh/hardware cloth.
I went to an area mulch/dirt yard to get some top soil and just happened to ask about pine bark fines and they said they stopped making them because there wasn't a demand. They also said they didn't have any pine bark at the moment due to decreased logging and businesses shutting down.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
There are hundreds, if not thousands of 'theys'. So you can bet that 'they' didn't ALL stop bagging pine bark. ;o)

If you're using the 5:1:1 mix or something similar, please don't concern yourself with the finest fines. I use the partially composted pine bark fines straight from the bag & don't screen anything. It's only for the gritty mix and my bonsai soils that I screen. (Actually, I don't screen too often - I usually use pre-screened fir bark.) Also, most of the bark suppliers are geared toward spring shipments & don't start bagging this year's product until spring.

Al
kandhi
14 years ago
last modified: 8 years ago
I am a frequest visitor on frangrant garnden forum but never visited this.Wow, so much wealth of information. It took me more than an hour to read the whole thread. I was able to grasp atleat 1/4th of it. Thanks to Al for patienlty answering everyone's questions. Now I know why my jasmine plants are failing on me. It is the standard miraclegro mix I use. For tropical jasmines should I use this recipe:
5 parts pine bark fines
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime (or gypsum in some cases)
controlled release fertilizer

If lime, how much should I use? I cannot find pine bark fines here, the only thing I can get is pine mini nuggets. Thanks
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Use a level tbsp of dolomitic (garden) lime per gallon of soil, or a half cup per cu ft.

I'll hope that if you look hard in the spring you'll be able to find a bark product a little finer than the nuggets ...... fingers crossed for you. ;o)

Welcome to the container forum. I hope you're a frequent visitor/contributor!

Al
chester_grant
14 years ago
last modified: 8 years ago
Having read this thread I can see that my idea of adding a handfull of teabags to a container soil mix would work - it would tend to prvent water flow and negate aeratiation. I might try one large container as an experiment - as I produce so many teabags there has to be a use for them somewhere....
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Did you mean to say "my idea of adding a handful of teabags to a container soil mix would (not) work."? I would discourage the practice. If I used them, it would be in the gardens/beds.

Arabica (coffee) and Camellia (tea) are known for their toxic alkaloid (caffeine) content and their allelopathic affect on plants as well as autotoxic (to their own seedlings) effects on future generations. Caffeine interferes with root development by impairing protein metabolism. This affects activity of an important bio-compound (PPO) and lignification (the process of becoming woody), crucial steps for root formation.

We also know that the tannins in both coffee and tea are known allelopaths (growth inhibitors). There are ongoing experiments to develop herbicides using extracts from both coffee and tea that cause me to want to say they might serve better as a nonselective herbicide than as a tonic. I would not use either on my containerized plants.

Al
katskan41
14 years ago
last modified: 8 years ago
Hi all. I wanted to share some information about using cat litter in place of Turface in Al's Turface/pine bark mini nuggets/granite soil mix.

I found a bag of unbranded cat litter in the garage a few days ago. It's unscented and contains no dyes or perfumes, etc. I have read on some forums where some members substitute cat litter or OilDry for Turface in their soil mix. I've had great luck with Turface but decided to experiment and see if cat litter would hold up to soaking in water.

I found a small plastic cup, added some cat litter and then poured water over the top. Imagine my surprise when the cat litter immediately (within minutes) went from solid clay particles to gray mud. The cat litter broke down completely and immediately, certainly nothing I would want to use in any of my containers!

Now to be fair I only tested this one type of unbranded cat litter so all brands may not be this bad, but for use in containers there's no way I'd ever use this in my soil mixture, unless you wanted gray mud.

I have not tested OilDry and probably won't since I have a bag of Turface in my garage.

I just wanted to let members know that in my opinion cat litter should NOT be used in Al's container soil mix unless Turface or similar product is not available locally *and* the cat litter has been carefully tested beforehand.

Thanks everyone.

Dave
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
"Carefully tested" is the key.

Thanks. ;o)

Al
katskan41
14 years ago
last modified: 8 years ago
You are welcome Al. Just didn't want anyone on the forum to mix cat litter into their soil without testing.

The cat litter and OilDry products are, I believe, similar to Turface, except the clay has not been fired to a high temperature like Turface.

In all honesty I *did* expect the cat litter would break down eventually, but thought it would take a few days, maybe even a week or two, not five minutes!

If you can't find Turface in your area you can also use Schultz Aquatic Plant Soil (available online, in pet supply stores, Walmart, etc.). I believe it's the same as Turface but is sold in smaller bags and is more costly than Turface. If you only need small amounts of Turface for soil mixes this might be an option.

Thanks everyone

Dave
phoenix7801
14 years ago
last modified: 8 years ago
I tried to get a product called dryz-it to break down by pouring hot faucet water on it. It held up so I put it in a pan of water and boiled it for twenty minutes. It held up. I think it'll work for this task
katskan41
14 years ago
last modified: 8 years ago
I'm not the expert that Al is on this topic but if you can use Dry-It in boiling water and it doesn't break down then I *think* it would work for soil building. Again, Al or other experienced members of this forum might have better advice.

Last night I spent time on various bonsai sites, and all of the sites had extensive threads on soil building. Although I didn't have time to read each and every post on how to build soil, here are a gew general things that I took away from the threads:

1. Turface: A tremendous product for use in most bonsai and container applications. PRO: It's extremely stable and will not break down. Great as a soil component. CON: It can be difficult to find in some areas.

2. Moisture absorbers: Various products like OilDry, Dryz_it, etc. can be used in soils in place of Turface if tested beforehand. I believe these products are similar to Turface, however most are not kiln fired to such a high temperature as Turface, therefore they could break down faster. I would carefully test these products by soaking in water for extended periods and see what happens. PRO: Easy to find at auto supply stores, hardware stores, Home Depot, etc. and inexpensive. CON: Some break down faster than others, so test before use.

3. Cat litter: Quite a few members used cat litter in place of Turface or OilDry and had mixed results. Some users said it worked well, while others said the cat litter broke down and turned to mud in a hurry. (As posted earlier in this thread, I found the same thing.) Overall I personally would avoid using cat litter as there are so many brands and contents available that it would be a major effort to find one that worked as well as Turface. PRO: Inexpensive and available everywhere. CON: Many brands break down into mud in a hurry.

So those are my two cents worth! Again, Al or other members of the list may have other opinions but if you can find it I'd stick with Turface. If you can't find Turface and feel like experimenting with some expendable plants then maybe try the OilDry to see what happens.

Thanks.

Dave
tapla (mid-Michigan, USDA z5b-6a)
Original Author
14 years ago
last modified: 8 years ago
Nothing to add or disagree with, Dave. Thanks. ;o)

Since the thread has topped out again at 150 posts, I'll leave a link to the new thread for those that may have interest in following it. I can't tell you how much I've enjoyed not only the discourse, but the amity as well.

Thank you all so much!

Al
intercessor
14 years ago
last modified: 8 years ago
Any body use cocoa shells in the soil? Lowes or Menards do not have composted bark but they do have plan bark and cocoa bean shells. Just curious.

Tnx

Container Soils - Water Movement & Retention V

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