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howelbama

nitrogen deficiency in gritty mix?

howelbama
12 years ago

Hi,

I recently created my first batch of gritty mix using repti bark fines, sorted and screened, gran-i-grit, and turface all sport. All the ingredients were well screened to eliminate dust. The repti bark is fir bark fine that are uncomposted.

I have a small pepper plant growing in it, and it is showing overall deficiencies, but primarily N.

Is this because the fir bark fines were not composted and are tying up the nitrogen? The deficiencies are showing in the oldest leaves and I am still getting new growth.

Sorry I can not post pics at the moment, but I will try to as soon as I get a new camera...

Comments (26)

  • Joe1980
    12 years ago

    You left out the most important bit of information: what are you using for fertilizer, how much, and how often? Gritty mix provides no nutrients.

    Joe

  • howelbama
    Original Author
    12 years ago

    Joe

    Right now I am using gh 3 part mixed to 1/4 strength and fed with every watering. I'm using their growth ratio for the 3 part. I would like to use fp but my local nursery has the gh readily available at good prices and I'm familiar with it.

    Thanks again.

  • calistoga_al ca 15 usda 9
    12 years ago

    A shortage of nitrogen will usually be indicated by the older leaves being robbed of their nitrogen in favor of the new growth. Regardless of the source you are not providing enough nitrogen. Most of us feel using FP despite the problem of finding it, it is worth the trouble. Nitrogen is available anywhere, but not in the balance with all the other minerals and nutrients your plant needs. Al

  • howelbama
    Original Author
    12 years ago

    Thank for the feedback. I'm going to try upping the strength to 1/2 and see how it responds. I'm also going to order some fp soon:)

  • Joe1980
    12 years ago

    I was reluctant to order the FP 9-3-6 at first too, because it was pricey, and had to be shipped. I got mine from Amazon.com, for $23. It's the best $23 I've spent, at least in regards to my plant hobby. Everything is doing great with it. I figure it will take about 2-3 years to use the 32oz I bought, which is quite cheap when you look at it that way. The only thing I've done to better my gritty mix experience is lose the pine bark fines. I have some jade cuttings in clear plastic containers, and when watering, noticed that I was getting dry spots in the middle of the mix, and they happened to be where there was a tad more pine bark. I sat one of the containers fully submerged for an hour, and still, those spots remained bone dry, grit and turface included. So, I kicked the pine bark to the curb and use grit & turface only, and I am much happier.

    Joe

  • howelbama
    Original Author
    12 years ago

    Just ordered fp, cant wait to see the results when I get it.

  • meyermike_1micha
    12 years ago

    Oh, and by certain you will not be dissapointed!

    I would make sure you regularly on a consistance basis feed when you get it. It is the best stuff I have ever used if used faithfully.

    Mike

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

    Not being critical of you, H - just making a general observation: If any container gardener has a N deficiency in his/her plants, it's grower error. We really need to take full responsibility for ensuring all essential nutrients are present AND available at all times. The best way to do that is to consider the soil virtually inconsequential as a source of nutrients. Container culture is MUCH more like hydroponics than it is like growing in the earth.

    Good luck! I second or third (agree with) the FP suggestion. It really does make life easier; and I've yet to find anything that in my experience makes me feel my plants have a better chance at growing to their genetic potential (within the limits of other cultural factors).

    Al

  • howelbama
    Original Author
    12 years ago

    Al, I know it was my error for sure as I was definately underfeeding, just wasnt sure if there was a possibility the bark could have been tying up some of the N and making the prob worse. Your mix is great, I was going to ask if there really was any difference between using the gritty and hydroponics... I suppose it is basically manual hydroponics... Btw wish me luck, bracing for Irene...

  • emgardener
    12 years ago

    I have a tub of peppers in gritty mix also.

    Basically I gave up on them, because they did need to be fertilized with almost every watering and dry spots were/still are there.

    With a fast draining medium and liquid fertilizer, you basically do have a manual hydroponic system and should be prepared for the extra maintenance to tend to it.

    Since I personally decided I couldn't keep up with ongoing fertilization, I switched on tub to a 2:2:1 mix bark:peat:vermiculite and put in CRFs. These are doing better, but got a last start.

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

    Ohhh - good luck! I have other friends on the coast going through the storm and about to. I said a prayer for them, and I'll say another before sleep - I'll be sure to include you (I promise).

    All container gardening is much more like hydroponics than growing in the garden. On a scale of 1-10, with growing in the garden being a 1 and hydroponics being 10, container culture, whether using the gritty mix or MG potting soil, is probably a 7 0r 8.

    FWIW - I water with a water break and just make sure the surface is covered - never have dry spots. I fertilize in the summer about weekly when I can and it's not too hot, In the winter, I fertilize with a very low dose every time I water. This has always produced exceptionally healthy plants for me.

    The bark breaks down so slowly it's unlikely there would be any N immobility due to it - especially because it's a small fraction of the mix. There would be a far larger immobility consideration in soils comprised of larger organic fractions - especially those with fine particles.

    Best luck!!

    Al

  • meyermike_1micha
    12 years ago

    Al:

    You are so KIND from Mom and I. The lights are flickering and I think we will loose electricity. Till then, thank you dear friend!

  • howelbama
    Original Author
    12 years ago

    Al, thanks for everything. Made it through the storm with no major problems...just have no power...thanks to smartphones and usb chargers though I can still get my GW fix lol...

    I also water with a breaker head on my watering can and I think that solves any potential hydrophobisity issues with the gritty as I have yet to see any dry spots. I think some may be having issues with that because they possible are not making sure the ingredients are thouroughly mixed or homogenized if you will...prior to using the mix. Just a thought...

  • emgardener
    12 years ago

    Dry spots in my tubs were/are caused by using a drip system. Every couple of weeks, I do go out and hand water with a hose on the shower setting to fully soak the mix.

    I'm still trying to optimize an automatic watering system for container vegetables.

  • Joe1980
    12 years ago

    My watering issues aren't because of how I water, because I've tried many of different ways. They are also not because of my mix not being mixed enough. It's hard for people to understand what I am describing, unless they've seen it. Like I've said, using a clear container, I can easily see the dry spots. I've used the shower sprayer on the kitchen sink, the faucet running full bore, and even a full out submersion. None of which actually wet the those dry spots. It appears as though the little pieces of pine bark have formed little shields, setting in just the right way to form something like a wall, which repels water. I can't speak for the center of the mix, because obviously I can't see it, but it is definately a problem on the sides. I have to wonder if that is happening in any other pots I have.

    Oh, and another thing I've wondered about is with my schedule of fertilizing with 1/4 tsp of FP 9-3-6, as the instructions say, every time I water. Could this cause an issue with plants that don't go dry all too often, like succulents, say, being watered once a week or so? I just wonder if I should be applying the "weekly dose", as opposed to the "maintenance dose" if I am watering once a week?

    Joe

  • meyermike_1micha
    12 years ago

    Joe:

    Some are very religous about fertilizing their succulents and some not. I fall into the catagory 'not'.
    Mine still look fantastic even though I only fertilize once a month or so, if that, in the gritty mix.

    Mike:-)

  • mikedavid00
    12 years ago

    Ok but here's the problem.

    If she is using 1/4 tsp of FP in TAP water of a 7, her PH will be about 6.5 which from what I understand.

    I think it was Al that said 5-1-1 is a soil PH of 5 and that the PH of the feeding should also be between that.

    But if you see the chart below, you can see if you have a soil PH of 5, just how problematic it is.

    Here is a link that might be useful: Further reading

  • mikedavid00
    12 years ago

    Also I should mention that I'm not completely sold on how fast the dolomite lime is acting. It's in a pellet form. I don't see how those random pellets very sparsely throughout the bark is going to create a higher soil PH all around. And if so, how fast does it take for those pellets to act?

    If you take Manure, perlite, and peat moss, you can mix it for a solid PH of roughly in the 6.5 range or a bit lower and verify the soil PH.

    But with the bark, you can't verify the soil PH at all. You have to go on blind faith. I think the PH is so low, it's possibly causing deficiencies and other slews of nutrient problems.

    The Pine Bark Finings themselves are at 4 to 4.5 aren't they? This is extremely acidic.

    Everyone ignores the countless posts of people saying they did not have success with mix. Not here, but on other websites like that hot pepper forum.

    I think what's happening, is the mix is way too acidic for MANY people depending on the type of bark they get, their tap water, and depending on if the dolomite lime is actually working to increase soil PH or not.

    There's just too many people having problems to ignore and we need to find out what the issue is and why people stop using the mix.

    I joined the list and had to transplant out of the mix. I tried everything I could. I'm still trying to get to the bottom of what the problem is when I know for certain I did *everything* right. Particle size, pine bark, FP, you name it.

    All I can zero it down to is a PH issue combined with city tap water that may have too much calcium who knows.

  • greenman28 NorCal 7b/8a
    12 years ago

    Soil pH is far less important than the fertigation solution pH.

    I've also been told (at the Citrus Forum) that bark isn't acidic and doesn't have a low pH.
    I don't believe it, but that's what I've been told.

    The Dolomitic Lime that I use is in powder form, and very evenly distributed.

    Josh

  • Joe1980
    12 years ago

    Here's my take on this one: I grew a few things this year in the 5-1-1 mix, including 4 jalapeno peppers, 2 bell peppers, an elephants ear, a large pot of cannas, my daughter's zinnia seedlings from kindergarten, and besides that, I have some indoor plants in the 5-1-1 as well, including 2 chinese evergreens, a lemonlime dracaena, a large ficus alii, a pothos, and a lucky bamboo. I did have my pachira and schefflera in it as well, but they filled out the pots with healthy roots in about 2 months, and are now in gritty mix minus bark.

    Now, all of the above plants did are are doing very good in the 5-1-1 mix. However, I did find a flaw, and it seems to be a problem with a few others too. The problem is the hydrophobic nature of pine bark. I was having wilting problems at first, and though I was going to be a 5-1-1 failure, until I dug down into my mix and found that it was repelling water, but looked wet in the top 1 inch. Of course plants will die with that happening, so I adjusted my watering to account for the problem. I truly believe that a lot of people may be having this problem, but don't know it. I've found it to be so much of a problem, that I probably won't use it anymore, because it adds unnecessary time to my watering methods. I am switching all my indoor plants to gritty mix minus bark. Yep, just turface and grit, with differing ratios depending on the plant. I find that the pine bark caused watering problems in the gritty mix as well.

    Oh, and trust me, I have tried everything when it comes to watering, including different bark, and still have the dry spot issues. Also, for the lime thing, it should be in powder form, not pellets.

    Joe

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

    Mikedavid - there is a difference between the preferred pH ranges of mineral (gardens/beds/....) soils vs the highly organic soils we grow in. Even the 1:1:1 gritty mix with its 33% organic fraction is considered a highly organic soil. See the chart below for preferred pH in container soils.

    Josh is correct, too. The pH of the soil solution is much more important than media pH when it comes to container culture, with 'ideal' easily being a full % point lower for containers than gardens/beds/ag fields ......

    You can see that the 5.0-5.5 range, or even a bit lower, is very favorable for container culture.

    Al

  • howelbama
    Original Author
    12 years ago

    Al, it looks like somewhere around 5.2 or so would be ideal according to your graph for everything except possibly manganese...though the manganese looks pretty flat across the board unless you go very acidic...

  • ykerzner
    12 years ago

    Tapla - is the consistency of your batches of either gritty mix or 511 such that the water drains so quickly that it seems like it's going through large rocks, or does it pool a bit? I have had no success with peppers in 5:1:1 because the water kept going right through and out the bottom. The plants were big and green but produced no fruit (and I don't think it was a nitrogen excess).

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

    All my soils (even the 5:1:1 mix) drain very quickly. Water runs through the gritty mix so fast it's almost like there's nothing there to slow it down, and the soil has to be pretty much fully colonized by roots to slow water down to the point where it's possible to overflow (over the top) any pots larger than 4", unless the size of the drain hole is very restrictive, this, even with the hose flow control wide open.

    I prefer my soils this way. I feel that maximizing aeration within the limits of our ability to keep the plant hydrated offers the best opportunity for plants to grow to their potential; and yes, it does require the added effort that comes with shortened intervals between waterings, but that's something we need to decide individually - whether or not we're down for the added inconvenience. For me, it's a no brainer - I'm glad to go the extra shift for healthier plants, but not all our priorities are ordered along the same lines, and there is no fault in how they're established.

    I will say that I've grown peppers and plenty of other fruiting plants in the gritty mix with very good results, both in terms of yields and plant vitality, but I'm not growing in Texas heat, either - possibly a consideration. This year, all my peppers are in the 5:1:1 mix and are very happy, in spite of the fact that we've had several 2 week stretches of temps in the upper 90s this summer, and it's 92* now as I write.

    You guys worry a LOT more about pH than I ever did. My water is very high in pH at an average of 8.8. Still, my plants get all the nutrients they need and exhibit no deficiencies in the summer, as long as I flush enough to stop carbonate accumulation and it's upward push of pH in my media. Winter is a little different. I DO see some Fe deficiency toward the end of winter for indoor-grown plant material because I'm not set up to flush the 150 or so indoor plants as thoroughly and freely as I can when they're outdoors on the growing benches. So, in winter I acidify my irrigation water and fertigation solution, which corrects any Fe issues and I assume any other micronutrient issues that might want to tag along. I also frequently include applications of an Fe chelate formulated for high pH situations (Sprint 138) 4-6 times yearly.

    Al

  • Joe1980
    12 years ago

    Ykerzner, if your peppers were big and green, then it is not the 5-1-1 mix that is causing your lack of fruit. I suspect you are having issues with blossom drop, which results in NO peppers. I see you're in Texas where it's good & hot. Peppers, of all types, are quite specific in their preferred temperature range when it comes to flowers and fruit. During the day, it needs to be between 70 and 90 degrees, and during the night, 60 to 70. Anything outside of those ranges (give or take a few) will cause flowers to drop. I would have to imagine that in Texas, you are seeing too high of a temperature, probably day AND night. You may try starting them earlier next year, in hopes that your plants are in the flowering stage eariler in the year when the temps are in the specified range.

    Joe

  • greenman28 NorCal 7b/8a
    12 years ago

    I've got to agree with Al and Joe regarding the heat.
    Texas heat is going to pose some special problems with gardening.
    Even on my back deck, the heat was causing flowers to drop on my peppers
    in the 5-1-1. So I moved the containers to an area of the garden that receives
    mosaic sunlight throughout the day. Almost immediately the pods began to set.
    Shading the containers helps greatly, too.

    By the way, Al, thanks for that handy pH chart.

    Josh