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tillygrower

Failure to thrive issues using Gritty Mix

tillygrower
11 years ago

In early spring, after reading much of the information that Al was kind enough to post here on Gritty Mix, I decided I needed to give it a try. I mixed up 1:1:1 rinsed Gran-I-Grit Grower size: screened orchid fur bark: screened Turface. I put different (outdoor) plants in the mix, including a jade plant, a geranium, a 1 ft tall Japanese maple, a Meyer lemon, Christmas cactus, and a bougainvillea. I am fertilizing weekly with Foliage Pro (1 tsp/gal), to which I sometimes add 1/4 tsp of Pro-tekt. My water pH is in the 5.5-6 range. I am using the dowel method to know when to water next.

Despite all of this, none of these plants seem to be thriving. I'm seeing next to no new growth. After months of doing little, the Meyer lemon finally made a crop of flowers, but they all dropped off, no lemons. The temperamental bougainvillea survived the transplant to gritty mix just fine, but isn't growing at all. The Christmas cactus (the only plant I have kept indoors) never seemed to recover from its initial transplant shock, and always looks somewhat wilted.

I have read enough posts in this forum to know that my experience is unusual. People have raved about how well this mix works. I am obviously doing something wrong, but I don't know what it can be. Any suggestions would be greatly appreciated! Thanks!

Comments (35)

  • dickiefickle
    11 years ago

    Isn't Folliage Pro supposed to be mixed at 1/4 tsp per gallon ?
    My guess is overwatering and/or too much fert

  • calistoga_al ca 15 usda 9
    11 years ago

    I have to take the opposite tack from dickiefickle above. I do not find the gritty mix to be subject to over watering and one teaspoon of foliage pro weakly is not too much,in my experience. I water the heck out of my plants in gritty mix, and they love it. Al

  • tillygrower
    Original Author
    11 years ago

    Thank you all for your input. Al, the Turface is MVP. I gave up on finding bulk bark locally, so I ended up having Oak Hill Gardens send me some fine fir bark-- so I'm pretty sure I'm OK on the bark, too. Could I be under-fertilizing?

  • capoman
    11 years ago

    Tillygrower, is your bark well composted? I've been unable to get my usual bark this year, and had to go with another source which is less composted. I had to add some slow release fertilizer to the mix as I couldn't seem to get enough nitrogen to the plants, especially when it would rain and wash out nutrients.

  • tillygrower
    Original Author
    11 years ago

    Capoman, my fir bark is non-composted. It's mainly produced for use in orchid culture, but is clean and nearly the perfect size right out of the bag.

  • greenman28 NorCal 7b/8a
    11 years ago

    For the Gritty Mix, you definitely want the uncomposted bark.

    Josh

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

    I suppose you could be under-fertilizing, and you've got some room to move (toward a stronger solution), so I'd try that.

    Are the containers getting too hot? Plants DO go semi dormant during periods of extreme heat, if that describes your recent weather. Were you careful to keep the roots from drying out when you repotted? You bare-rooted - yes? I'm stumped, but all I can think of now is something related to some root damage at repot time or the heat. Hopefully everything will straighten itself out soon. I hate being perplexed & unable to offer anything meaningful! ;-)

    Al

  • tillygrower
    Original Author
    11 years ago

    It has been record-breaking heat here in NC for the past week, but these plants have been in their pots of gritty mix since March or April, when it was still relatively cool here. All were bare-rooted and I kept their roots moist during the repotting process. Maybe I'll try to increase the strength of the fertilizer. I've also got everything in unglazed clay pots. Except for Christmas cactus that I keep indoors, nothing else looks wilted, but maybe I should increase the frequency of watering??

  • redshirtcat
    11 years ago

    I can't speak to the other plants but I have 2 bougainvilleas and quite a few citrus in the gritty mix. The citrus will only flush 2-5 times a year depending on conditions and variety so give the Meyer some time. This year I moved to much higher concentrations of fertilizer with my citrus in the gritty mix and I'm seeing better results (I also moved away from FP but that's another issue).

    The raspberry ice bougainvillea that I bare rooted and repotted into the gritty mix was sulky for 6 months after the repot last year (I did it in the Summer) but it is flourishing this year as is my other noid bougainvillea. Both were suffering in the gritty mix until they got better pH-adjustmented water (sulfuric acid down to 5.5) and a supplemental micronutrient package (FP wasn't cutting it). Your pH looks much better than mine so I'd just give the bougainvillea some time as well.

    Do watch both the bougainvillea and any citrus trees you have for signs of Zn, Mn, and Fe deficiency. Pretty much all of my citrus trees were suffering from Zn+Mn deficiency after a year in the gritty mix (this was with FP and Osmocote Plus). Again: I had to move to a better program to acidulate my water and I've taken to giving them foliage sprays of Mn+Zn on Spring flushes - sometimes every flush if the Zn deficiency sticks around.

    Also make sure you're controlling any rust on the bougainvillea... I let that slip last year because I wasn't watching it carefully.

  • redshirtcat
    11 years ago

    "adjustmented" - sigh, why can't we edit posts at GW.

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

    TG - FWIW, I've been using FP for 3-4 years almost exclusively on a wide variety of species without even a hint of something being nutritionally amiss. I'm not saying there isn't something better, only that it's the best product I've found. For me, it's so close to an all-purpose fertilizer (so close to using it on everything) that the only plants I change anything for are tomatoes and tropical hibiscus, and for those I simply add a little KCl or ProTeKt to the fertilizer solution.

    It's hard to over-water the gritty mix, but extra water in the soil doesn't necessarily mean the plant will take up additional water; more often, it's the opposite. Plants function best when there is only a thin film of water on soil particle surfaces and water vapor in the pores. Unless you find that after a repot situation, all your plant's roots are in the upper portion of the soil, if you can detect moisture on the dowel you're using as a tell, your plants prolly don't need water yet. Remember, plants are better at extracting water than we are at detecting it, so even after soils FEEL dry, there is still a considerable cushion (around 15%) allowing plants to take up water we think isn't there. That doesn't mean you should take chances or depend on the plant being able to get water from soils that feel dry, just that dry to us isn't necessarily dry to a plant.

    Al

  • tillygrower
    Original Author
    11 years ago

    My gut feeling is that I'm having fertilizer issues. Al, would you suggest I go up to 1.5 tsp/gal of Foliage Pro, applied 1X/week? Are there any issues with fertilizing when it is really hot? (It's been nearly 100 now here for about a week.) Thanks everyone for your input!

  • tillygrower
    Original Author
    11 years ago

    Redshirt, I am curious about what fertilizer program you are currently using with your Meyer lemon trees...

  • calistoga_al ca 15 usda 9
    11 years ago

    I feel happy to not have the heat you are suffering with. I do however have a soil thermometer, I would insert in my container at about four in the afternoon. I would like to know just how much my soil is heating up to during the day. Al

  • meyermike_1micha
    11 years ago

    Well, quite an interesting conversation here and hello to all!

    I am quite perplexed as Al is too. You might find out on your own as I did and then one day share your experience like me.

    What I can tell you based on my experience with the gritty mix is that, I have never had any of the issues that many speak of here due to the FP unless used incorrectly, or the wooden dowel method.
    In fact, I must admit, I have yet to learn to 'grasp of the obvious;' other than the fact that by the time I realize plants need water, they wit.
    By then it is usually to late and I have killed yet another plant.
    It use to be that I would always over water, but now who would of thought I would kill a plant under watering, or at to some degree cause some root death, which would set my plants back again.

    What I can also tell you is that I do grow just about anything in this mix, including citrus, and found that I too was having the same issues at one time.
    I had to fiddle around with the fertilizer regimen and while at the same time wait many months for certain plants to recover from a switch from peaty mixes to the gritty mix, not due to the gritty mix by any means, but due to the process in which I repotted.

    Maybe you can relate to any of these potential problems that I had to realize over time, sometimes too late?

    I would do a lousy job at surrounding EVERY root after a bare root at repotting time.
    I would under water, leaving the top half of the roots to die of thirst, while the lower half would remain moist, causing a root die back problem stunting top growth.
    I didn't fertilize enough, and, I was not consistent.
    I did not use vinegar at every watering while using tap water, causing nutrient deficiency issues all over the place.
    I found that certain plants do not take very well at the onset, in particular, tropical, and certain citrus, but they would thrive after a few months of patience.
    I did not water enough on new plantings.

    if I was guess my biggest limiting factor as to why my plants did what yours are doing today, I would say, root damage and low nutrients.

    Believe me when I tell you, that once you get this thing right, you will see your plants THRIVE as mine are doing today, with the FP, gritty mix, and wooden dowel use.
    Don't forget that if you do get discouraged at some point and should decide to move away from the gritty mix on certain plants, there is always the 5.1.1 mix or something similar. I assume you have learned the concepts on using a very porous mix and it's benefits thanks to Al?

    Just my two cents after a very sleepless night.

    Mike

  • tillygrower
    Original Author
    11 years ago

    Hi everyone, I'm bumping this thread back up to report where things stand. I tried increasing the dose of FP, to no avail. Two Christmas cacti plants remain wilted looking, no matter what I do-- they are clearly not going to make it. My Meyer lemon is in stasis-- no obvious significant growth despite nearly 6 months in gritty mix. A foot-tall Japanese maple also failed to grow this summer. One geranium plant was looking so pitiful that I moved it back to the MG mix it had previously been in. (I know, horrors!)

    I'm really frustrated! The concepts behind all of this make so much sense to me. I have followed the recommendations on gritty mix to the letter, yet it's not working for me. I can't figure out any reason why. It can't be the granite or Turface, and the bark I got from Oakhill Gardens, which I believe Al has previously used.

    My only thought is the heat. I had all of these plants in clay pots, and it was one hot summer here. Do you think it is possible that clay pots+girtty mix+sun/heat just don't work well together here in the South?

  • rina_Ontario,Canada 5a
    11 years ago

    tilly

    I can't offer any advice, just understand how frustrated you are; I repotted Meyer lemon (it had lots of flowers & 6 or 7 small lemons when I got it, and cost me almost $30...) just like you, and it lost all flowers & lemons, and few leaves soon after. I thought that it's going to die. I put it ouitside, watered dilligently, and just waited to see what it will do. It took more than 2mo of nothing, then it started (slowly)looking better & better, flowering and also putting out some new leaves. Looks pretty good now.

    I also fully repotted ficus Benjamina, complete job with major root pruning. I followed Al's instructions to a T, and this tree is doing really great.
    Also repotted lots of succulents into gritty, they are doing really good.

    I would not increase dose of fert if they are not looking healthy enough.

    I would think that clay pots are better, plastic is usually hotter. (BTW, most of mine are in plastic still).

    I keep plants outside in full sun, but kept them in more shady location for about couple of weeks after repotting.
    I water with abt. 1/8th dose of MG 12-4-8 added with every watering.

    What - if anything - did you do with roots when repotting?

    Rina

  • tillygrower
    Original Author
    11 years ago

    Rina, I barerooted everything before transplanting, keeping the roots moist the entire time. Newly transplanted plants were kept in the shade for a couple of weeks before gradually being moved to sunnier locations.

  • TheMasterGardener1
    11 years ago

    tillygrower,

    Report back on how your plants are doing now that you got them into some potting soil. Growing in a inert hydroponic media is not easy. ;)

  • greentiger87
    11 years ago

    I too can only sympathize, because everything I put in the gritty mix seems to turn into a weed (as long as I keep fertilizing). I actually don't use Foliage Pro for many of my outdoor plants, Miracle Gro All Purpose 24-8-16 + chelated iron and micros + occasional epsom salts works fantastically and is a bit cheaper. I doubt that would solve your problem though.

    When I've made gritty mix correctly, really coarse with lots of air space.. I don't worry about overwatering at all. In fact, I drench the pots completely whenever I feel like it, sometimes everyday. especially after transplant, I usually do morning and evening watering. How do you even use the stick method for gritty mix? It shouldn't really work right?

    I usually save clay pots for 5:1:1, but I do have three gritty mix plants in unglazed terracotta. 1) Holy Basil 2) Murray koeniggi or Curry Leaf, a citrus relative 3) Lemon Eucalyptus. The clay allows me to quickly tell if they're dry just by putting my hand against the outside of pot towards the bottom.. it stays slightly damp and cool. All three are growing out of control, I have to hard prune them constantly... which is fine because they're all very useful :D Clay should be close to ideal for the southern sun (I'm in Houston, TX, so I have it even worse than you)...the evaporative cooling and insulation provided by the clay is really great.

    The only suggestion I have is to use humidity tents, in a partly shaded area, or even just at night.. especially for any plants that are wilting.

    I've seen so many photos of Christmas Cactus in what in the gritty mix, and I have an Epiphyllum in it as well. But these are rainforest cacti, so they evolved in a place with very high humidity. The humidity stays high even when there hasn't been much rain. If you're going to recuperate the christmas cactus indoors, I think a humidity tent is just necessary.

    The only plant I have that has failed to thrive in the gritty mix is a Japanese Maple, but that really has nothing to do with the mix - it's just my zone. I suspect it would have died a long time ago if it was a commercial potting soil.

    Did you put gypsum or lime in your gritty?

  • meyermike_1micha
    11 years ago

    Actually I respectfully differ with Mastergardener when he says that growing in the gritty mix is more difficult.

    For me, growing in the gritty mix is much 'easier' and so is growing in the 5.1.1 mix. I find that these two mixes are more forgiving than regular fine particled potting mixes. The only issue I would have is whether or not I can find the time to water and fertilize more often and that is when adjusting the mix to fit my lifestyle comes into play, not that of what is best for my plants.

    I find that growing in the fine particle ones does not allow me to water often and as much as I like and confines me to 1 size bigger than root ball pots. I can't leave most of plants outdoors subjected to days of rain without rotting. I get constant issues with fungus gnats, mold and mildew. Other pest issues were always present and salts deposits build up quickly.
    I have had to consistently flush my soils out and watch for over watering problems.
    For most that I know of, this kind of care is more time confusing and has a much more expense along with it. This is difficult.

    One is not confined with the 'gritty mix' as is, but can adjust it to work for them. Understanding the concepts behind a well aerated mix is what is most important and can be used to your benefit and that of your plants. Understanding how water and roots behave in your containers is a plus!
    If you find it dries out to fast, you can add more water retentive materials. The porosity of it actually encourages good plant growth.

    I find that as soon as I transplant a plant into the mixes I use from that of finer mixes, they actually take on more vigor almost immediately.

    I hope you get to the root of your problem.

  • hookilau
    11 years ago

    Gritty mix issues. I had a couple, but all were due to user error. Specific plants that didn't seem to do well were; banana, patchouli, hot pepper, cacao and probably a few others I can't remember just now.

    Most didn't quite fail, just didn't really thrive. I unpotted to see what was going on. I found that although roots closer to the top of the pots were healthy, there was almost none at the bottom. I also noted that at the bottom of the pots I had wet, sludgey oil dry (turface substitute). Blick. The roots had encompassed the entire circumference of the first 2/3 of the pot but must've died having reached the sludge (i made my own pwt - yay) duh. I didn't screen well enough.

    I used screening material that was too small & so although I had no fines, (ie: grains that were visually the size & texture of sand) I still needed to screen out the 'mediums' =)

    I bought a sheet of #7 plastic canvas (cause I'm a craft lady too) and cut the bottom out of a plastic shoe box. Then I tie wrapped the plastic canvas to the bottom (with teeny tiny tie wraps courtesy of Home Depot) and got to re-sifting. I was quite surprised at the amount that fell through =/ The pots even felt light after watering, so I knew this was *my* issue.

    Plants that didn't care about re-sifting and were thriving, were re-sifted anyway due to potting up & prepartions for winter. This included all my DR's, jades, pineapples, and assorted succlulents. If we had a longer season, I would've left them in the gritty & waited it out. Since the weather is turning cooler soon, I wanted to see growth before they were brought in. I didn't want them limp along till next spring or worse, give up during the winter before they got back outside.

    I repotted my pepper plant in 511 and he immediately responded. Every day like clockwork, he would wilt alarmingly despite having been watered in the morning (this guy was the one with no roots at the bottom of the pot). The next day, no wilt. Perfect. On to the next...banana, patchouli & cacao are still trying to decide but have shown no signs of stress of any kind, so I have to believe they will be just fine in this.

    For me, I'm pretty sure the ones that didn't thrive, would probably have recovered quicker if I had done this at the beginning of the season. Next year, I still have the option and I'll probably do just that.

    My hot peppers will come into the house in the *well screened* gritty and I'm betting all will be well =)

    While I realize my experience may not be what's troubling your plants, if someone else is having issues, hopefully it might provide some insight. Lots of variables to consider.

    Antoinette

  • emgardener
    11 years ago

    Antoinette,

    You wrote:

    "I repotted my pepper plant in 511 and he immediately responded. Every day like clockwork, he would wilt alarmingly despite having been watered in the morning (this guy was the one with no roots at the bottom of the pot). The next day, no wilt. Perfect."

    Does this mean the pepper didn't wilt every day after you repotted? Thanks. I've had similar problems.


    greentiger,
    Just read your post, thanks for the clay pot tip. Never thought about touching the outside of one to see if it needed watering.

  • hookilau
    11 years ago

    Yup. I repotted him in the 511 from the gritty late in the afternoon & did not water, but misted the mix so that it was damp. I put him in dappled shade. The next day, I expected to need to water but he was standing proud and has not wilted since.

    It's a very small plant in a 4" pot. The plant itself is only about 8" tall from soil line. I think it may have been the stress of the combination of putting out fruit & high daytime temps & improperly screened gritty mix. Here's what he looks like today, the re-pot took place the end of last week, Thursday or Friday. Rain on LI today =)

    Antoinette

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

    Tilly - this is really puzzling. For me, it doesn't get any easier than the gritty mix. As long as I water/fertilize, everything I ever planted in it thrives. It's not often I'm at a loss for suggestions, but I am today. I feel especially bad about the disappointment after your considerable effort and I'm sure, high hopes. I wish there was something I could do to help. Can you think of anything I could do?

    Al

  • tillygrower
    Original Author
    11 years ago

    Hi, all. I'm bumping this thread back up, because I thought of another possibility that might (?) explain the problem. In reading through some of the other threads on the Citrus Forum, there is a discussion about people preferring plastic pots for their citrus. Based on what I had previously read, I thought citrus benefited from clay pots because they "breathe" better. Maybe that was a mistake. I'd be somewhat worried about cooking the roots in a black plastic pot in full sun here in the NC summer, but I could look for a lighter-colored pot, for ext summer. Could the clay pot be the reason my Meyer lemon languished all summer? Indoors now, by the way, it seems to be a bit happier... even flowering...

  • aseedisapromise
    11 years ago

    Tilly, I think that with clay pots, at least at first after watering, and maybe later too, they experience evaporative cooling, which would tend to keep things cooler rather than hotter. Sometimes in hot, hot summer, which granted here isn't as hot usually as you experience, I will water some all around the edges of the pot just to cool it down. Misting might be good for some things, like one poster mentioned. But my plants I was talking about were pelargonium geraniums, that actually like to be cool, and not have wet leaves. I also use pots inside of pots, with plastic only, to give a pocket of air as insulation. I also move them to the shade during the hottest part of the summer. Also I have used some mulch on my pots, to keep things wetter during hot weather. I have had some issues with my changes to gritty mix for some plants, and so I am also trying to work those out, and I think hookilau has some good things to say to me, so thanks for posting this. I am going to do some serious screening this spring. I have heard some folks say that pure bark is a good thing for holiday cacti. That the gritty mix is not so good for those. I have tried 5-1-1 and that seems to work well, but I have some that in the spring I am going to try all bark for them, maybe some that is composted more than what I have used for the gritty mix.

  • jodik_gw
    11 years ago

    I grow mainly indoors, and I grow mainly bulbs... I also grow mainly in a rendition of the Gritty Mix.

    I have found that before I mix a batch, I need to soak the bark a bit so it's moist. If I do this, and I make sure I'm in keeping with the concept of the medium with regard to particle size, screening, etc... I have no issues following a re-pot.

    Also, aftercare is very important... ensuring that the plant has a good opportunity to adjust to it's new medium out of direct sunlight and winds.

    But if I fail to pre-wet the bark, or keep in mind the concept of the medium and aftercare, I'm doomed to failure.

    I found that there's no cheating when it comes to good preparation of the ingredients, using the right ingredients, proper aftercare, and that my habits in watering and fertilizing would change. I'd be watering more often, and feeding on a more consistent basis.

    One other thing I found is that not every plant will enjoy the Gritty Mix. There are a few that are happier in more moisture retentive circumstances... so I adjust for this using medium that more closely resembles the 511, or by adjusting the ingredient ratios or using different ingredients, creating a custom medium for the plant in question.

    Ambient temperature is a consideration in certain climates, too. Growing indoors, I keep pot edges from touching the window glass, and keep leaves off the glass, too. My preference is unglazed clay, though I do use a few plastic pots for certain plants more sensitive to temperature or moisture retention.

    One of the biggest mistakes I made in the beginning was not watering enough, and not ensuring the bark was pre-soaked prior to mixing batches of medium. But if I'm honestly doing everything exactly as directed, I have no issues, whatsoever. I think the keys are in understanding the concept, not taking any short cuts, adjusting my care habits, and understanding the limitations of my unique environment and those of the particular plant I'm trying to grow.

  • JoppaRich
    11 years ago

    Funny about the pepper. I've got an Aji Lemon that I moved to gritty a couple of months ago, and its doing fantastic.

    I've also got a ton of small citrus trees in gritty and doing great.... except for my Eureka lemon, which has been slowly losing leaves since roughly July. It looks terrible. Not sure what the issue is... It was a much bigger plant than the other ones when I repotted it, (and had a much bigger rootball), so my guess is I did something wrong with it.

  • greenman28 NorCal 7b/8a
    11 years ago

    Joppa, how often are you fertilizing the Eureka?
    I've found that lemons are quite heavy feeders for the most part, and leaves will begin to yellow
    as soon as nutrient levels diminish.

    Also, did the bigger tree get a bigger pot?

    If so, could there be excess moisture in the larger volume of mix?

    Just thinking out loud until I learn more....


    Josh

  • sans-fan
    10 years ago

    Hi everyone!
    I happened up on gritty mix while surfing the Internet for information about sanseveria in the spring.
    Intrigued, I decided to try it because many of my plants had suffered last year from too much fertilizer.

    This year I was concerned that my sans were getting too much rain because here in n. ga, it has been raining a lot.

    So, I bought all the ingredients and set to work with the sifting,washing etc. and placed most of my sans in the gritty mix.

    The rains continued to fall and the sans in the gritty mix seemed to be faring WORST than the sans in the regular heavy soil! The leaves were turning yellow at the top and getting really ugly brown spots.

    I un-potted a couple of them and noticed that my turface (I was actually using the Napa product) was migrating to the bottom of the pot and I guess holding water on the roots.

    Has anyone else had this experience? What have I done wrong and how can I correct my problem. I feel guilty because my plants seem to really be suffering!

    Thanks,
    C.J.

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

    The only way your DE would be migrating to the bottom is if you didn't screen it. How did you make the soil?

    Al

  • sans-fan
    10 years ago

    Hi Al,

    Thanks for your reply! I used sifted soil conditioner, gran-I-grit and the Napa DE. At first, I did not wash the gran-I-grit or sift the DE but I did not want the roots to suffer so I went back and did those things.

    When I combined the ingredients, the DE particles were definitely the smallest. The sifted soil conditioner size was maybe a bit larger than the size you recommend but about the same size as Reptile Bark (in the small bags).
    The gran-I-grit is developers size.

  • greenman28 NorCal 7b/8a
    10 years ago

    With a disparity in particle size, the small particles will migrate and settle between the larger. When potting, it takes great care to keep the particles evenly mixed. But it's best to screen ingredients, rather than compensate afterwards.

    Josh