Now that I've used some of the Golden Trophy premium mulch, I can't recommend it. It's full of large chunks of pine and shreds of what looks like painted wood :~( Apparently not made the way it used to be. I really didn't want the extra work of screening stuff. Blech.
Container Soils: Water Movement and Retention II
Awwww bummer. That's a shame. I still have about 10 bags left over from a couple of years ago (bought a pallet) and it's perfect. I didn't look closely at the stuff they had this year because, at a glance, it looked only borderline usable because of its 'too large' size.
An acquaintance from another forum site though, said she bought about 20 bags from a pallet that was behind the fronted pallet, even climbing OVER the one in front to get at the 'good stuff'. I'm assuming the more grower-friendly product was last year's material.
I used Fafard's aged pine bark this year and it looks good. I did cut back on the peat and added a little more perlite so it drained like I like it though. I can already tell I'll need to water less frequently. Time will tell if I like that idea or not. ;o)
Al
Would Ozmocote Plus Propagation grade 12-14 month, (http://www.scottspro.com/_documents/tech_sheets/H5124OsmocotePlus.pdf) eliminate the need for a separate addition of micronutrients in your Basic Soil Mix? It is available at my local farm supply store and it seems like all it lacks is calcium (and that come from the lime so isn't needed in the controlled release). I have a bag of this from another project and, although expensive, if it would eliminate the need to find the micronutrient powder it would be more convenient for me than finding and using a special micronutrient powder.
Also, my local farm store has 50 pound bags of a non-controlled release fertilizer called Super Rainbow Plant Food 16-4-8 which seems to have most of the micronutrients - just lacking B and Cu (http://www.rainbowplantfood.com/products/grades/SuperRainSouthern.htm). I was thinking about using it as a light top dressing now and then to cut back on the more expensive Ozmocote in the mix. Although the Miracle Grow might be a better choice for that.
Thanks,
Dan
It would, yes. I went directly to the link before I finished reading your post & also noticed the Ca as glaringly absent, but that's no problem if you're liming - especially since the Mg content is only 1% (antagonistic deficiency extremely unlikely).
I'm assuming the 16-4-8 is a soluble chemical fertilizer and not a collection of soil amendments? If you're using the 16-4-8 intermittently at reduced application rates or as a supplement, you should be fine. It has more N than is needed in relation to both P and K, but the P:K ratio is a good one. As diligent as you seem willing to be, you could probably dispense with the CRF altogether, unless your intent is simply to use it so it doesn't go to waste. Even though I include it in the soil recipe, it's mainly insurance for those who don't/won't/can't fertilize regularly.
Al
Thanks Al,
I just mixed some container media according to your big batch recipe. The texture, pore space, and "mixability" is better than any by-the-book formula I've tried, including the peat lite ones. And it is a rather light-weight mix too! Thanks for the info. If there were any change I'd make it would be to try to find something to replace the peat (only because it is the most expensive ingredient in my area - pine bark here is relatively cheap). But I can't figure out anything less expensive that has near the same characteristics. Only thing I can think of locally available is very coarse cypress sawdust or possibly pine needles shredded to fiber or maybe shredding a fraction of the pine bark fines even more fine but I doubt they would really replace the peat. Spaghnum peat just seems to be magic stuff. I probably should take a nice camping vacation up to Canada and bring back a van-full of the big bales.
The 16-4-8 is a granular chemical fertilizer (soluble since it is chemical but not one of the ones meant to be diluted with water like Miracle Grow). I use it on the plants in the soil garden. The farm store recommended it for my sandy subtropical soil that holds on to absolutely nothing. It is very good for growing greens - and pretty much everything else. I also use it to hasten decomposition of wood chips to turn them into compost since it has lots of N, then I feed the super compost to the garden. That is one that I have around all the time so I thought it might be a good supplement for top dressing containers using your mix. I already use it for containers using a pine bark/compost-based mix (no CRF) and it works well but it is hard to tell how much of the micronutrients come from the compost vs. the fertilizer. Anyhow, the compost portion of the mix decomposes so fast I have to keep making new "soil" so replacing it with a more stable mix is attractive. For the containers with your recipe I probably will stick with the CRF for now since I am not always around to do a regular fertilization (and I have a *lot* of container plants). But the 16-4-8 might still make a good top dressing when the rain would do the work rinsing it in.
I'm still looking for a good long-lasting 100 % "organic" media and fertilizer mix made from local ingredients for the organic group I work with. Can't find anything that really works to my satisfaction - I don't think you can really stuff a whole year's worth of cheap, local, organic fertilizer into a gallon pot without it burning the plants at first and starving the plants later on. Organic mixes are okay for one season vegetable crops but nursery containers really don't seem to be feasible unless you top dress frequently with expensive materials like blood meal and such. No one seems to believe me on that so I keep on trying - persistence may not always lead me to success but I always learn something or other from it - and the journey is ofter fun. For my stuff at home I think I'm going to use your mix with the CRF from now on (especially if I can find a cheap peat replacement!).
Dan
PS - a picture of one of my container gardens is attached for fun.
Hey - your garden looks great!
Dan - I used Fafard's aged pine bark this year & cut back on the peat because of its fine texture. I really think I could have done w/o it, as I've done many times before. I don't think there's really anything too special about it, other than it's a very useful tool in getting the water retention just right. I have a pal on another forum that grows in a combination of just pine bark & Turface. Come to think of it, my best friend (CA) grows practically everything in a mix of composted redwood bark and Turface. It's all about the combination of texture, particle size, and the balance between air and water retention. It doesn't matter HOW you get there, just so you do. ;o) Of course, durability is a huge plus. Chopped celery has plenty of aeration at first .....
I used to think I could get good (comparative) results from going the all-organic way, but I've resigned myself to the idea that while in the garden, 'feeding the soil' is the best way to approach husbandry, in containers it's not going to be as productive, it will probably be more difficult, and when you do get stuck with a problem, it's much more difficult to extract yourself from it . I don't want to get into a big skirmish with those that adhere to 'all organic' practices in containers because there is room for both points of view, but it's just much more difficult to grow in compost/manure/topsoil and use soil amendments as nutrient sources than it is to use a well-aerated and durable soil and a soluble fertilizer regimen.
... but you're right, the journey is the reward ....
For some reason, I'm right now reminded of the words to a John Denver song that I really like
"(there's) only two things that money can't buy,
that's true love & homegrown tomaters."
Al
Lolol!!! Strong work, Gloria!
I often have that song/CD playing while I'm working in the gardens. I'll be walking around & can't help but stop & do a little stutter-step before I finish gittin' to where I was goin'. ;o)
Al
"Chopped celery has plenty of aeration at first ..."
Wow - I just chopped down all the celery stalks. Now I have a use for them. :-)
Great to hear that the peat is optional. I'll have to try a pine-bark-only mix and maybe up the watering frequency (most of my containers are on drip irrigation so I can change it to eight short waterings a day if I get a different timer). I might worry a bit about the CRF all sinking to the bottom of the container through the pores if the pine bark is too coarse. Might need to add a bit of fiberous stuff (like the cypress sawdust) to prevent that - or maybe not. Worth a test or two. When I add compost there is a tendency for the compost to sink to the bottom of the container and the pine bark to stay toward the top when the rains beat down but the compost particles are a lot finer than the CRF beads so that might not be an issue using just pine bark and CRF. It would sure make mixing even easier!
The local lumber mill also sells its pine bark composted with sand (they call it potting soil) at about the same price as pine bark alone. I've sort of ignored it in the past since it is a lot heavier to haul home and unload than the pure pine bark but maybe a load of that is worth experimenting with too. Some pots need a bit of weight to prevent them from blowing over.
Dan
Another type of "container"
Hey Grrrlgeek and Stressbaby,
I live in Pleasant Prairie WI which is not far from Grayslake and have been having trouble finding high quality pine bark this year. I bought 3 different brands and all were duds. The Golden Trophy "Premium Landscape Pine Bark Mulch", as you noticed, looked the worst. Even though they claim on their label that the "American Mulch Council" certifies it, whoever they are, it looked like it was about 5-10% recognizable pine bark and the other 90-95% of it looked exactly like shredded, dyed, wood. It was so stringy that I couldn't even sift it through a 1/2" screen it to do an analysis of its particle size distribution. I looked closely at 2 other brands that looked like a lot of dirt and pine needles were mixed in with the pine bark. So now I'm looking for the Farfards brand pine bark. Finally, after 2 years, I found and bought Scotts Micromax on-line in 1/2 lb jars for $6.00 each from a bonsai supplier. I also found Scotts S.T.E.M repackaged and sold on-line @ $7/lb from an orchid supplier. I'm not sure how to transmit these vendors to all of you since Dave's can get all freaky and go Medieval on you if it looks like someone is getting free advertising here. I have no connection with the sellers by the way.
If anyone knows how I can send the word out on these items w/o offending the gods, let me know.
I love that "home grown tomaters" song too and my big city friends can't understand why.
Nathan
I went through Pleasant Prairie today. Stopped at Jelly Belly hungry. Oops.
Yeah, that Golden Trophy stinks. Some bags seem better than others, but no way I could screen it. What does the "American mulch council" certify it as I wonder :~P I did use a little anyway for a few things that needed potting up NOW, but still looking for stuff that needs to be in containers for any length of time.
Someone somewhere said BFG Supply has the Fafards aged pine bark (BTW, how are you supposed to pronounce Fafard anyway?). The closest location to us is Brookfield though, so I'm trying to find something closer first. I picked up a couple of bags of pine stuff at Grayslake Feed this afternoon but haven't really looked at them yet. I need mulch anyway so I have somewhere to put it if it's too big. If you do go to BFG, the people who went said they seem to charge different amounts to different people, so maybe call ahead to get a price. They charged from about 9.00 to 12.50/bag from what I heard.
Good luck, let us know if you find anything interesting,
Sandy
I think this is the only thread that has a theme song - and a dance! Al's stutter step to go with it!
Sandy, I'm very obtuse and don't even know what BFG Supply is or where it is. Can you clue me in please?
Thanks.
Nathan
Not obtuse, I never heard of them until I read a post about them. Their site is http://www.bfgsupply.com/content/ . Apparently they're mostly wholesale but do sell to the public, though they don't have prices marked on anything, so you have to be careful what they try to charge you. I think I'm going to get the Fafard stuff from them; I'll have to figure out which is closer, Brookfield or Joliet. I think it's a toss up.
The stuff I got at Grayslake Feed would need to be screened, but at least it's screenable. It would take me forever to screen all I need if I use it for all my veggie containers. It's called Robin Hood Pine Bark Mulch, made by the Hood Timber Company (I think-I'd have to look at the bag again). It was 4-something for a 3 cu ft bag.
HTH,
Sandy
Sandy,
I'm going BFG soon to get some Farfards bark. A trip to Brookfield has a lot less traffic and construction than a trip to Joliet but from Grayslake it may be a different story. Thanks for all of your help Sandy.
Nathan
LOL, I broke down and went to Joliet and got some yesterday. I had to go south of here for an appointment already, but it would probably still would've been better to go to Brookfield. Too much traffic :(
Hey guys. I don't want to hurt any feelings, but we're straying, & I'd appreciate it if we could try to steer the conversation back to the original topic. Thanks. ;o)
Al
Thanks, tapla --I love following good discussions here, but lots of "false alarms" lately.
Soil is key to container gardening --critical to get it right, especially as plant and pot size increases and do-overs become impossible.
Soil's "only " roles:
1. anchorage - to let plants hold themselves upright
2. aeration - to provide for most of a plant's "inhale" of oxygen and "exhale" of by-product gasses
3. water source - to hold water sufficient for the plant's needs, with required nutrients dissolved in accessible form
Sounds simple? Not so, since what improves a soil for one of the three roles, can ruin it for another. What maximizes anchor-strength could preclude aeration. The highest degree of water retention can be the worst for a plant's air supply. And perfect aeration qualities might leave a plant prone to dying of thirst. And (subject of many emotional posts here!) some materials that provide good aeration, solid anchorage and nice water retention can decay too quickly, all while producing chemicals that "lock up" the dissolved nutrients, preventing roots from uptake. Lots to think about!
Tapla's digest of advice and related discussion here is really all about how to achieve the right balance for each container garden situation.
This has become a long forum, and hard to take in, unless you've been following it, but it's more valuable than any other place in all of Dave's Garden, IMHO. If you're new here, I suggest reading --and re-reading--Tapla's initial posts and then searching for where he responds to specific questions. Much of the rest is interesting, but all is more valuable if you focus mainly on those and at least initially skip the digressions.
The info has made a world of difference in how I go about putting any plants in a new pots --ESPECIALLY large plants going "permanently" into large pots.
Thanks, tapla, for keeping the "class" on topic.
This message was edited Jun 16, 2009 9:18 PM
This message was edited Jun 16, 2009 9:20 PM
Great synopsis, JPlunket. And yep, this (or these) threads by Al are chock full of great info. They have helped quite a few folks, no doubt about it.
Thanks, Al.
Shoe
Thanks for all your information Tapla. I'm trying to find all the ingredients to try and there has been lots of discussion about pine bark fines but what the heck is "micronutrient powder"? The only stuff I can find is for human consumption and to help you lose weight.
Can you clarify this a little more?
Thanks so much.
Berengaria
Thanks for the very kind words, JP & Horseshoe - much appreciated. The best part of your comments comes from the fact that they reinforce the idea that I kight be helping. That's important to me.
B - There are a number of preparations that are designed to supply the micro-nutrients that many fertilizers leave out. I use Micromax and STEM (by Scott's) extensively, but they are hard to come by in quantities the average hobby grower would find reasonable. I don't think you want to pay around $100 for 50 lbs that will last you 100 years. ;o)
The easiest way to solve the issue is to use a fertilizer that contains all the essential nutrients in a favorable ratio to each other. Foliage-Pro 9-3-6 does this. It supplies nutrients at very close to the same ratio in which plants use them. This allows you to fertilize at much lower rates (by rates, I mean lower EC and TDS of the soil solution) while still preventing individual deficiencies. It takes much of the pressure off by eliminating most of the guesswork. I would guess that the 9-3-6 is suitable for almost everything you grow. I can use it on everything I grow with good-great results.
If you still want a micro-nutrient preparation, try Earth Juice Microblast. It should work just fine. A word of caution: There is a narrow range in the micro-nutrients between deficiency and toxicity, so more is not necessarily better. Be judicious.
Al
Thanks for your quick reply. I've seen your wisdom on so many sites my head is spinning.
Foliage-Pro 9-3-6 sounds like a good choice for me, with my inexperience and small collection. One more question, please. Is it applied as a liquid fertilizer to the pot or is it sprayed on?
With much gratitude for your generous and gracious sharing of your time and knowledge.
Berengaria
Thanks, B. You are too kind.
It's a liquid that you mix with your irrigation water & apply to an already damp plant. It would work marginally well in a very dilute solution as a foliar fertilizer because it derives most of its N from nitrate forms, and urea is the preferred source of N for foliar feeding, but foliar applications as a generalization are actually very ineffective. They don't change the fact that there is a soil deficiency, the majority of plants don't respond to foliar applications of fertilizer because of a thick/waxy cuticle (leaf skin), and since most foliar applications are targeted at relieving deficiencies of secondary macro-nutrients or micro-nutrients, most of which are not mobile in the plant, they relieve leaf symptoms only, and for a limited time. While I'm on the subject, I might mention that nutrients in organic form, as opposed to ionic form, are even less effective because there is no primary pathway for absorption of large organic molecules, and they are not broken down into ionic forms with any efficiency on leaf surfaces. Even secondary pathways for ionic forms of nutrients through stoma are ineffective pathways for organic molecules.
Applying nutrients to the soil is the best way to fertilize. Foliar sprays will not improve growth unless nutrients are inadequately supplied through the growth medium. Reserve foliar feeding for plants that are growing so rapidly they cannot assimilate enough (usually) N, Fe, or Z. IF you use a foliar spray with Fe in it on containerized plants and it causes them to green up, it's indication that media/soil solution pH is too high.
Al
This message was edited Jul 21, 2009 2:54 PM
Al, you are amazing.
I've seen no mention of media wetting agents. Years ago I bought some Aqua Gro, a wetting agent that helps water uptake. My well water is very hard so I use mostly rain water to which I add a small amount of Agua Gro to the full rain barrel (20 gals.?) I think it is used on golfing greens, too.
What is your experience with wetting agents and your subsequent advice?
Thanks again.
Bere
For foliar spray applications or to add to irrigation water to help correct hydrophobic media?
Al
To add to irrigation water.
If you need it, you're probably letting your soils dry down too much. Both peat & conifer bark become hydrophobic at around 30% moisture content. Soils though, feel dry to the touch at around 40% moisture content. Plant's vary, but most flowers & crops are able to extract moisture from soils until they reach around 20% moisture, then the moisture is locked so tight they cannot utilize it. If you water soon after your soil feels dry, you shouldn't have any problem with your soils absorbing water. An exception could occur if you're using organic sources for nutritional supplementation. Organic fertilizers like the various meals tend to promote an algal crust on top of soils that can be hydrophobic even when soils are above 40% moisture content. Then, technically, it's not the soil that's hydrophobic but the crust.
Surfactants reduce surface tension and make water wetter, so it can then make its way into the tiny pores in dry soil particles that would normally remain closed to water because of that surface tension. Soil particles will eventually absorb enough water to relieve the hydrophobia though, even w/o a surfactant. Often, you can achieve the same results as if you were using a surfactant, by watering the soil & allowing it to rest for several minutes before you return to water more thoroughly a second time. While surfactants do insure a better chance at evenly wetting the soil, they're primarily used in commercial applications because they save time by eliminating the need to water twice.
Al
Thanks Al, I value your opinion and knowledge very highly. For 50 years I've been potting in bags of potting soil and wondering why my plants never did too well. Now I'm off to try a new experiment and search the local stores for the ingredients.
I'm also trying a new experiment with my front porch/greenhouse. I never let it get below 40 degrees in the winter but last winter was so cold for so long that I had to heat it for many weeks thus running up a big bill. I've gotten rid of all my orchids and Boganvillea and am trying out plants that for the most part are evergreen but can stand a little frost or freeze I'll only heat when it is very, very, cold outside. Crazy? Who knows. Time will tell. In the meantime, I think I better re-pot my new purchases to give them a better chance.
Thanks again for sharing.
Berengaria
Al, I have one more question. Sound familiar? I have a feeling I'll always have 'one more question' for you.
What would be the best medium for rooting cuttings of plants like Cotoneaster and Pyracanthra?
I've found all the materials, pine mulch, crushed granite and Turface and Foliage Pro 9-3-6. I'll be all ready to start repotting as soon as it all comes. At what strength do I use the Foliage Pro and how often do I apply it?
I guess that is 2 questions.
You're turning into my bible on container gardening. I'm so glad I found you.
Berengaria
I have rooted them in my raised beds by simply sticking dormant cuttings in the well-aerated soil as soon as the frost is out of the ground.
If you want the best results, bundle & bury 6" dormant cuttings (with their proximal [closest to the roots] ends up) for the winter. Bury them vertically so the proximal ends are about 2-3 inches deep, and the distal ends deeper. Callus will form quickly on the proximal end in the warmer surface soil, but the cooler soil below will help suppress bud movement until roots have formed. When the buds of similar plants in the landscape just start to move in spring, dig up the cuttings & plant them like you normally would - maybe with 2/3-3/4 of the cutting buried. In spring, when you right the cuttings, roots will already have emerged through the callus on the Pyracantha (or will soon), but not necessarily on the Cotoneaster - those roots will occur in various places along the cutting. Or another strategy - after digging them up you can stick them in containers in a 50:50 mix of screened Turface and milled or chopped (in a blender or food processor) sphagnum moss (not to be confused with sphagnum peat moss - they're different) before buds move in spring and after danger of temps
Al, can crushed granite and crushed marble be used interchangeably?
Thanks in advance for sharing your expertise.
Berengaria
Dr. Tapla,
Various spots in my lawn, perhaps where trees roots are decaying (?), have sunk noticeably.
What mix of Turface and other materials would you recommend to level and reseed these spots? How deep into the now-sunken surface soil should the new material be incorporated --minimally / ideally?
I know, I know, this is not technically a container garden soil question. But a lawn seems to me an analog for other "permanent plantings", potted or not, where the decay and compression of organic material creates an issue, so I hope it's germane to this forum.
I'm going to say no, although I'm not absolutely sure. I do know that granite is primarily made of quartz , and feldspar with a little mica and potassium thrown in, while marble is a recrystallized form of limestone that formed when the limestone softened from heat and pressure and recrystallized into marble. It mainly consists of calcium and dolomite. Marble can classified into three categories, which makes it even more difficult to give an all-encompassing reply.
1) Dolomite: If it has more than 40% magnesium carbonates.
2) Magnesium: If it has between 5% and 40% magnesium
3) Calcite: If it has less than 5% magnesium carbonate.
We want a small residual fraction of Ca in our soils, which is why we usually add dolomitic (garden) lime to the 5:1:1 mix and gypsum to the gritty mix. We purposely add the gypsum (CaSO4) to the gritty mix to help keep the pH low. Container soils should be about a full pH point lower than garden soils, which we usually consider 'ideal' at around a pH of 6.2. Even though (practically speaking) CaCO3 (marble) is considered insoluble under normal conditions, we know it's NOT, under acid conditions. I'm quite, but not absolutely sure, that using fine crushed marble as one of the mineral components in the gritty mix will lead to pH issues high enough to cause deficiencies of several micro-nutrients, and possibly some of the macros and secondary macros. Because of my reasoning, I wouldn't use it, but there's nothing to stop you from trying & (hopefully) reporting back to us.
Perhaps there's a REAL chemist in the house who could offer a definitive answer?
Al
This message was edited Aug 2, 2009 10:22 AM
JP - It is kind of off topic, but, expense aside, I wouldn't use Turface or similar to touch-up these areas. I would use use native soil, or you'll likely see a contrast in color and growth characteristics in those areas. Turface is used extensively on golf course turfs, but they apply voluminous quantities of water on a regular basis to maintain healthy turf.
Al
OK, thx
Hi Al,
Thanks so much for your patience in helping us understand how and why container soils behave the way they do - - I've been surprised at how long it's taken me to start to 'get' it.
My local masonry supplier has a nice clean crushed limestone gravel thats screened, washed and about the size of 'grower' grit. It's very inexpensive, 'bag my own', and in an effort to save money at the volumes I'm using, was wondering about the effects of limestone in a container soil mix, and if it could be used instead of the crushed granite. I'm watering with collected rainwater or relatively soft gravity fed spring water. I use Foliage Pro with both - -
I was surprised to see such a similar question from Berengaria above, and after reading your response, I see that this is probably not a good plan. Would soaking some gritty mix made with limestone, in water for a few days and then testing pH be a way to get a clearer idea, or are these types of interactions much slower paced than that? My farming friends tell me that adding crushed limestone to their fields is a slow gentle way of adjusting pH, and that hydrated lime (burnt limestone) is the quick path to higher pH - -
Ruminating a bit here, ;) I'm wondering if considering my water, a buffering element might not be so bad. Sorry if I'm asking questions outside your realm of interest or expertise - -
Thanks Again, Allen
The speed of the reaction will depend on the particle size (how much residue or dust is included in the product would have a fairly significant impact) and the starting pH of the media. Large particles like you're talking about are generally considered ineffective at raising pH because of their small surface area and thus low solubility, but I believe that is when referencing 'normal' application rates on fields. Also, when a farmer spreads limestone on his fields to sweeten the soil, he is applying an amount that would be considerably thinner than the thickness of wax on your car, when compared to the top 12" of soil - IOW, a minuscule amount. Your intent is to use it as a considerable fraction (1/3) of a soil, which is quite different by comparison. I haven't tried it as a 1/3 component of the gritty mix, but I have to say that I'm dubious about the results.
Another factor that needs to be considered: We use gypsum to guard against a too high pH in the gritty mix, but you are toying with the idea of using limestone in huge volumes. That gives me pause. What also needs to be considered is the Mg content of the limestone. We use dolomitic (garden) lime in our soils and gardens because it supplies both Ca and Mg in a favorable ratio. If that ratio becomes skewed so there is not somewhere between 2-5:1, Ca:Mg, you would definitely be looking at the likelihood of antagonistic deficiencies of Ca or Mg. If, for example, the limestone you would use is a calcite limestone (little or no Mg), you may not be able to add enough Mg to make it sufficiently available w/o raising the EC and TDS of the media sky-high and killing the plants.
I don't want to scare you off. I rather wish you would try it on a small scale & compare it to the 'original recipe' ;o) and see how you fare.
Al
Thanks Al,
For another thoughtful reply - - I like the way you think about these things. I'll try the limestone mix on some encrusted saxifrages in troughs, and a few other less lime-o-philic plants to see what happens. In the meantime, back to the feed store for more Grani-Grit. Luckily we have several commercial turkey growing operations in the area and there's plenty of grit around - Allen
tapla/wise ones,
I've got my tropicals in the pool bubble greenhouse for the season.
This is an environment I'd describe as cool rainforest --100% humidity, with constant slow dripping of condensate off the bubble. The heat source is evaporation from the pool surface, maintained at about 82 degrees. Air never gets below 45 degrees even on our coldest nights (10 degrees, say), usually 50 to 55 most days. Really inefficient, I know, but that's a different story. (details in an earlier post http://davesgarden.com/community/forums/t/939786/ )
I keep most plants up off the floor, without wicks. Soil is moist 100% of the time, even though plants go 5 straight months without us watering them once.
All but a few plants have survived over the years --crotons die immediately, for some reason, though the worst problem for others has been fungal spots, bacterial rot, or just unenthusiastic performance-- and some just love it in there. Still, I'd like see them all thrive.
GIven the extreme situation, compounded by the fact that all the plants move outside to their irrigated locations once it warms up each year.
Is their an ideal soil mix I can migrate to as I repot cyclically?
If you don't water for 5 months ....... is the water source for the plants the dripping condensate? I realize there is no evaporation from the soil taking place. What is the state of the soil as far as water retention is concerned - always soggy? Do roots at the bottom of the containers perish from the anaerobic conditions? What are you using for soil now?
My first impression is that you need a soil with large particulates that guarantees at least no perched water in the container. Because you mention they're under irrigation in the summer, it shouldn't be difficult to come up with a theoretical structure for the new soil that will work winter AND summer, but whether or not you will be able to fill the short shopping list is the first and only major hurdle. ;o)
Al