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girlfromthegarden

Help for parched figs using pine-bark potting mix

girlfromthegarden
18 years ago

Aaaarghhh.. it seems whenever I've tried valiantly to give my container plants a fast-draining potting mix (using Al's recommends), they are wilting unless I water them sometimes even more than once a day, and this has been in only 70+ degree weather - the mix is at least half pine bark mulch crumbles, with perlite, vermiculite and some potting soil (peat-based) comprising the rest. It's an attractive looking mix, lets the water run through it fairly readily (it acts more like sand in that regard), but I'm afraid that once the truly hot weather comes in, even if I partly sink them in-ground, they are going to bake and die of thirst! I've thought of buying those moisture crystals and stirring them into the already-repotted plants, to try to help them, but does anyone have better ideas? I simply don't have time with my schedule working full-time to water at least twice a day (or more) once it gets hot! or do I need to repot again into much larger containers (another investment) being careful not to disturb the roots since it'd be a second repotting, to try to increase the volume of container soil to root ratio? I know they need good aeration, but I feel like I'll have to go back to using something that's mainly commercial potting mix even if I have to re-do the soil yearly or every other year, just to keep the figs from wilting.

I ran into this last year, it's frustrating not understanding why it doesn't work better to hold any moisture - does the bark not retain water? Would the moisture crystal idea save me some intensive labor? (already have a lot of hours invested in potting with the "fast" mix, but I may have to re-do it, or lose figs to heat by June). Help!

Sherry

(tired of watering already, and it's not even May!)

Comments (17)

  • mountainman0826
    18 years ago

    Hi, Sherry,

    Regarding Al's "bonsai-influenced" fig potting soil, the ingredient that you do not mention is Turface baked clay granules (I think another name for the granules is haydite.) The granules are sold by some landscape concerns and are used for playing surfaces on baseball diamonds among other things. The baked clay granules hold water and nutrients. Adding more peat will also help to hold water, at least temporarily, as some of the peat will eventually wash out of the mixture. Following is a recipe that I calculated based on a discussion Al and I had last year.

    Soil Recipe for Figs

    3 Parts Pine Fines (2 cu. ft.) = about 12.9 dry gallons

    1 Part Turface (.66 cu. ft.) = about 4.3 dry gallons

    1 Part Perlite (.66 cu. ft.) = about 4.3 dry gallons

    1 Cup of Powdered Dolomitic Lime

    Osmocote 13-13-13 Fertilizer (1 cup = 244 g., 28 g.= 1 oz.) Â Recommended Application Rate for medium sensitive nursery stock is 6.5 oz./cu. ft. = 182 g./cu. ft. 182 g/cu. ft. x 3.32 cu. ft. = 604.24 g. total = about 2.5 cups of 13-13-13 per batch of 3.32 cu. ft.

    ScottÂs Micromax Micronutrients- Recommended Application Rate for nursery stock/pot plants is 1 oz. (about 30 g.)/cu. ft. (1 oz. = about 4 level teaspoons.) 3.32 cu. ft. x 30 g./cu. ft. = 99.6 g. or 12.4 level teaspoons or slightly over 4 level tablespoons per batch of 3.32 cu. ft.

    (Volume of Soil Batch is about 3.32 cu. ft. or about 21.3 gallons  I mix it in a large wheelbarrow.)
    1 cu ft. = 6.4285 US dry gallons

  • bjs496
    18 years ago

    Hi Sherry,

    I asked about wilting trees last year, and someone (I think it was Gene) made a distinction between trees that wilt during the heat of the day and those that remain wilted in the evening when things cool down. My trees are potted in equal(ish) parts pine bark, vermiculite and crushed gravel. We've already been getting 90 degree weather and I still generally water every other day in the afternoon. My Chicago Hardy wilts in the heat the same day I water, while others do not. I let them go three days without water this past weekend without any ill effects. You may want to see how far you can push the trees without water.

    There has been some discussions (primarily in the container forum) about moisture absorbing crystals. Some of the responses are favorable and others are not. It seems to me that once the pot drains, there should be enough moisture remaining in the micro pores of the mix to sustain a tree for at least a day.

  • girlfromthegarden
    Original Author
    18 years ago

    Kudos to the Texas Contingent for input :) - okay, re the idea of Turface, I've already asked the ex- if he'll do me a favor next time he drives out onto the northwest side of metro Indy while out on an appraisal, and pick me up two 50# bags of the stuff at the only distributor I could find locally when calling on it about a month ago. The question is, do I then need to re-pot the ones I'd already done with pine bark, vermiculite, perlite and peat, and re-mix using the Soil Recipe for Figs (which sounds pretty decent), even if they've leafed out significantly? or try the moisture crystals in some of them, and use the better water-holding mix for the ones that still remain to be re-potted (I've got quite a few, they've simply been on hold while I've been planting all the nurseries' shipped-in orders this past week-plus).

    I also think that maybe I should look at what Gene (or whomever) said about the wilting in high heat of mid-day vs. being that way at night also - it was primarily the extremely large leaves of the Mary Lane Seedless figs that were going down like beagle ears the other day, and I got them quickly into the shade, worried I'd lose them. Everything looks extremely healthy for the most part, though the one mystery fig that I gave the potent bare-rooting and pruning job to, is only *now* starting to push green again, hasn't leafed yet, obviously it went into moping mode after being de-chunked like that. Let me see about that idea of letting them go a day, and checking their status by evening when dusk cools things (actually we're seeing potential *frost* tomorrow night - eeek! this right after I went ahead and popped one Hardy Chicago in-ground to test-drive how a fig might do near the house foundation's micro-climate on the south-east side). I appreciate the input, though am curious what's said that's negative about the moisture crystals????

    Sherry

  • gorgi
    18 years ago

    My take on this, is that all this quick draining soil stuff may
    have some significant effect on new cuttings (rootings).
    Once the plant is established, this may become LESS
    significant. Any soil would probaply do, except perhaps
    the real 'heavy' ones...

  • leon_edmond
    18 years ago

    I must also add that part of the problem could be the black nursery containers which just about everyone is using to pot their fig trees. Those containers can get pretty hot in the direct sun. Not only does the direct heat dry out the soil, it also does a number on the new root growth encircling the inside of these little Dutch ovens. It is important to insulate these black containers from the direct sunlight.
    One solution is to bury the pots in the soil. Not only will this protect the fig tree from the heat, it will promote root growth out of the drainage holes into the soil thus limiting the need to water so often.
    The only drawback to this is the work needed to root prune the pots out of the ground when fall comes around.

  • girlndocs
    18 years ago

    One thought I had was, are you sure the pine bark is getting really good and wet when you water? It can be pretty dang hydrophobic when it's dry, and your water might be running through because the bark is repelling rather than absorbing it.

    Is there any way to set your fig pot in a larger tub containing lukewarm water for a bit, to let all the pine bark particles get really thoroughly damp?

    Kristin

  • mountainman0826
    18 years ago

    My vote would go for re-mixing with the turface clay granules included. Otherwise, you will have to baby the figs all summer, watering once and perhaps even twice a day, depending on the weather. If you do repot, do it as soon as possible. If the leaves have come out, I'd go easy on the root pruning, only opening up the periphery of the roots, so that the potted figs are not rootbound. I also agree with Leon about insulating the roots. For those in a southern clime, planting the trees in-ground is the best option, assuming you have the space. For those up north, if your situation (and energy) permit, then burying the containers in-ground for the summer is helpful in terms of keeping the roots cool and minimizing watering frequency.

  • tapla (mid-Michigan, USDA z5b-6a)
    18 years ago

    Sherry - How big are the pine bark chunks you used? Was the bark aged or partially composted? Is it possible your trees are wilting as a result of the reduced root system & not the lack of soil moisture? I grow many, many containers with the base mix 5:1:1-2 pine bark: sphagnum peat: perlite, with no watering issues. I also have a large group of container gardening grower/friends, local and on forums, using the mix with no bad reports at all. Really sorry to learn you're having trouble with hydration. ;o(

    YBIC&PA

  • bjs496
    18 years ago

    I did fail to mention that I went with all white pots this year. Last year I had two in white pots and top growth was more substantial for the trees in white pots than in black pots. Later I discovered the roots also were more substantial. Al's response to this was:

    "I believe it to be temperature related. The black pots are much more likely suffering more severe heat stress & would unable to metabolize properly & use water from the containers. The plants in the opaque white pots would be the coolest (possibly as much as 20* or more) of the lot & would therefore show more vigorous transpiration rates & be able to carry on (closest to) normal function.

    I often see water requirements (especially in plastic containers) diminish during the heat & usually don't fertilize containerized plants from around July 4 to mid-Aug in my zone. Most of my trees show almost no growth during this period, so use much less water & almost nothing in the nutrient department. Fertilizing at this stressful time can increase the probability of root rot. Though we rarely associate a weak or sickly tree in fall or spring with root rot, we can often trace the underlying cause to exposure to temperature extremes the summer previous.

    It is very important for me, in zone 5b/6a to be cognizant of high root temperatures & try to moderate them, & even more so for the growers in the higher # zones, like yours."

    This is why I not only switched to the white pots, but also water in the afternoon when I can.

    I remember reading about using one of the turface like products on a lawn. The recomendation was to aerate the lawn and spread the product so that it fell into the holes. Perhaps you could use a pipe to pull a few plugs of your mix out of the pot, mix the turface into what you pull out and pour it back in. You may be able to avoid repotting. Another option is to nest your pots in a larger one and fill the space between with more mulch as an insulator.

    The mystery fig you spoke of, is that from PN? Mine finally broke dormancy about three weeks ago... about five weeks after the others leafed out.

  • eukofios
    18 years ago

    Last year I placed a layer of aluminum foil, shiny side out, around my fig & tomato pots (I think this came from the tomato forum, keeping the soil 10 to 20 degrees cooler, but I forget the actual number). On the surface of the soil, I had perlite, which is bright white; or crushed eggshells, which are nearly white and contain calcium.

    I think the plants did not dry out as quickly as they did in the plain black containers, and I did not have to go out & buy paint for the pots.

  • girlfromthegarden
    Original Author
    18 years ago

    Am plumb tuckered and trying to operate via a rather sluggy dial-up (Midwest woes for DSL today, had no email or 'Net since morning at either home or office, but customer service folks got me hooked up the old-fashioned way even if it is only about 49 kbs) - this is quick, but thanks for input from all; yes, it's partly root-pruning that might be the culprit with the Mary Lane Seedless; definitely could be the pine bark mulch wasn't soaked enough (noticed that hydrophobic thing, too, Kristin), and didn't retain as much water as it could've; bark size was crumbles (nice size) and looked fairly aged, in fact, one bag sat outside since last season and *was* aged, so quite a few of the repotted figs in batch #1 had vintage pine bark of a smallish particle size; Mary Lane's were in green containers, not black nursery pots, but yes, I *will* either wrap in foil or white contact paper and/or bury partly in ground at some point to protect root zones. Will try the Turface "insertion" method before doing much total repotting, once I get some (don't know when that will be). Many of the figs that were repotted have shown *no* signs of wilting or heat stress, so take heart, Al, your mix and ratios *do* work! I think it's mainly a combo of some containers might've needed to be larger for the root-ball/pot volume ratio given the faster draining mix. James, the mystery fig *is* one of PN's, and it isn't leafing out yet, but getting closer to reviving from its below-soil-level "haircut". I'm zoning for the night, more tomorrow!

    Sherry

  • girlfromthegarden
    Original Author
    18 years ago

    Another thought, about keeping the moisture levels stable, also protecting the root zone - if using the wrapping-pots-in-foil idea, could it also be beneficial to bring the foil layer up and over the top of the pot, reflecting some light into the undersides of the leaves (I'd heard it baffles insect pests somewhat) and maybe punching some holes into the foil to let rainwater drain in, but would block *some* evaporative loss from the top of the pot? I'm not envisioning wrapping the dumb thing like a baked potato, exactly, would leave a fair opening around the base of the tree, but could that be helpful/feasible, even if the row of containers might look like something from a bad B-rate sci-fi movie from the '50's? Or do they need the top left open, but maybe the light-colored perlite or eggshell layer to reflect heat away? further ideas? - we have creative minds on improv'ing things around here, which I appreciate a lot - what think ye?

    (p.s. Al, I think part of the problem was some of the mixes were light on the peat, since recommends were to go soil-less and away from organic materials as much as possible, yet the peat-based potting soil mix holds water pretty well in those pots that have more of it. I just need to learn to make a more consistent mix for figs, is all, and add the Turface or similar.)

    Sherry

  • eukofios
    18 years ago

    Most of the fig forum folks recomment a layer of coarse limestone on the soil surface, which is white, shiny & reflective, so keeps the soil cooler and more moist than without the limestone, plus is a good source of calcium. Quick lime is not recommended because it overwhelms the plant with alkaline calcium salts.

    I used the perlite (even though it is non nutritive) because I couldnt find any crushed limestone. Plus, it floats, so doesnt get buried. I used the eggshells because... well, some people do speak in hushed tones around me. Egg shells are basically limestone that is produced by chickens for their own purposes, and so the effect would seem to be similar to limestone. Eggshells do have some nitrogen (due to the protein lining) but that doesnt seem to hurt anything.

    The foil does have a 50's B-movie space alien look, but Im not sure that white painted containers are all that attractive either. I told the neighbors that the foil deflects unfriendly radio signals. Anyway, there are worse looking things in the neighborhood.

    I'll see if I can find some old references to either the foil or the limestone, and link to them, later.

    Ciao

    Daniel

  • elder
    18 years ago

    If you grow figs in pots, you are going to have to water these plants more frequently than those growing in the ground. Last summer, '05, during the hot drought in VA I had to water my potted plants daily - until I wised up and buried them, pot and all, in the garden. The in-ground fig plants were never watered, even in the driest part of the summer. Had I used Turface would that have extended the watering times? I doubt it! The trouble with Turface is that it is hard to find, and when you do find it, it is really expensive. Usually at the bonsai supply houses. The idea behind bonsai is to miniaturize plants, generally woody plants. When we put figs in pots we want fruit production, at least most of the time.
    I have a copy of Ray Givens fig pages, for potting figs he recommends 2 parts pine bark (no size expressed), 1 part composted cow manure, and 1 part perlite, all dusted heavily with lime. I believe gorgi was totally correct, you can vary these soil mixes extensively, and it probably won't make too much difference as long as you're not making a swamp out of the pot.....Elder.

  • girlfromthegarden
    Original Author
    18 years ago

    I'll probably bury as many of the potted figs partly inground as is practical, given my yard's present set-up (would need to strip sod along the back first), but the rest will need some heat protection and probably some extra watering until I master the right mix to use in the pots. Maybe a space-alien look in my backyard will keep birds away from the rest of my berry plants! I actually do have a jar of crushed eggshells (I save them all whenever I cook, then mash them into fragments and store) that I'll try sprinkling in the tops along with perlite and some extra dolomitic lime (they've not been given any this season yet). Turface is about ~ $11/bag in this area, a few bags wouldn't break the budget, but I'd not count on it for being some kind of magic ingredient to alleviate watering duties or anything, just would help keep the nutrients in better, probably. Haven't gotten hold of it yet, and need time to re-do the pots that haven't yet gotten their (needed) larger-size containers, but hopefully I'll mix a more hospitable batch when I get to it.

    Sherry
    (wanting to play hookey from work on a pretty Friday and go dig in my yard the rest of the afternoon)

  • eukofios
    18 years ago

    Here is the thread on using limestone as a mulch. lots of information. I'm adding it because i think that it impacts this discussion as well.

    Here is a link that might be useful: limestone fig forum discussion

  • eukofios
    18 years ago

    Also, here is the thread on wrapping containers with foil.

    Here is a link that might be useful: 10 degrees cooler when wrapped in foil