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Diatomaceous Earth: Yay or Nay?

Discussion in 'Organic Growing' started by koudakat, Sep 4, 2009.

  1. I use diatomaceous earth in a sprayer as a natural pesticide on my other house plants. It works great, but leaves white powder spots all over the leaves. My question is: will those spots clog up marijuana's "pores"? Heres a link describing what it is: Diatomaceous earth - Wikipedia, the free encyclopedia
    Thanks all!:wave:
  2. The "pores" are the stomata on the underside of the leaves, as long as your spray the tops I guess it should be alright. Just dont spray the buds obviously.
    Diatomaceous earth is usually applied as a layer on top of the soil, for fungus gnats and the like. I used the powdered stuff and it mixed with the water to form a weird paste, so dont use that, use granules or whatever other form it comes in
  3. Thank you, yea the paste is kinda what it leaves on my Laurels. I appreciate the feed back..:smoking:
  4. #4 nevesone7, Sep 4, 2009
    Last edited by a moderator: Sep 5, 2009
    From what I have read about Diatomaceous earth, it actually dehydrates the pest. In almost every case that I have seen it used it was spread in a row along corners of walls and cupboards/pantry's (food grade) and a perimiter around plants or whatever it is your protecting from insects. no reason to really mix with water and spray on the actual plant...due to it's dehydration effects I would think it might be doing some leaf/cell/flower damage being sprayed directly on the plant???
  5. Well, in New Mwxico, we have a bad spider mite problem. One of my neighbors gave it to me and said to spray because spider mites gather on the leaves. Thanks guys or girls, I sprayed the soil but gonna wait on the leaves. Appreciate the feedback....:smoking:
  6. I actually use it in my soil mix (1tbsp/ga of pot). It is a good source of silica, which helps strengthen the plants tissue/cell structure, It also makes it more resistant to disease and environmental conditions (heat/frost/dehydration)

    I've used it to try to combat spider mites, but it isn't as effective as some of the other insecticides. The best organic insecticide I've found is Spinosad It contains a bacterium that targets most leaf eating insects, while sparing the beneficial insects such as lady bugs and praying mantis's.

    It has been particularly helpful to help me rid my plants of spider mites. I use
    Monterey Garden Insect Spray. It is OMRI rated and is only 16 bucks a quart. There are other products available with Spinosad.........check your local nursery/garden center.

    It won't hurt to sprinkle a little DE on the top of your soil as a preventative measure, but I'd personally refrain from spraying it on the leaves.
  7. So 1 tablespoon of D. Earth per gallon of soil (or soilless mix) is OK? I mean, it will not interfere with the plant's roots at all? Could you exaggerate a bit more my friend?:D:D
  8. #8 MI Wolverine, Jun 22, 2011
    Last edited: Jun 22, 2011
    I don't think you want DE anywhere near something your going to be smoking, your supposed to where a mask around it, I don't think you want to inhale tiny silicas....soil ya....but not on my plants.......MIW
  9. I was just about on my way to buy some DE. Still going but it's Neem Oil instead. :hello:
    Thanks for mentioning that tid-bit. Hadn't ran that through my thoughts yet.
    Yeah, that stuff is tiny little bits, that are little razors. Probably not really good on tissue. :D
  10. Very bad advice. :eek:

    You WANT the powdered form of diatomaceous because it's the food grade type, all-natural and safe for plants. The coarse stuff wouldn't kill a pest unless it ate it, where as the powdered can physically cut into their bodies and either kill them quickly or slowly. Most of the course diatomaceous is for pools, and is heated much higher during processing and is much more dangerous to plants and humans, especially if you grind that type into a fine powder. And the best thing to do for getting as much as you can of the leafs is use a dust can, the same you use to spray out your pc, just barely pull the trigger and get off as much as you can. Just use a air mask or bandana so no powder gets into your lungs.

    The powdered stuff is what you want. :smoke:
  11. More bad advice.

    This stuff is used in food friend, and it's fed to animals we eat. It is harmless unless it is inhaled in powder form in quantity, which is the type you SHOULD be using. Water renders diatomaceous useless when it comes to harming humans, so unless you're using it in your last day of flower which is silly, or you don't plan on watering your plants for the duration of your grow which is impossible, there is NO DANGER in using this product of nature. It does ZERO damage to marijuana at every stage, whether it be a seed in soil, a tiny seedling just sprouting, a 12" vegged plant or a mid flowering plant, which is the latest stage one should use it above soil, it will not hurt it or you. As a matter of FACT, it HELPS your plant and soil by protecting it from disease and other ills, it's great to use if you over-water, and it's actually a useable substitute or addition to perlite.

    Facts first, assumptions never.
  12. I just bought some DE last night for all these damn soil mites I have. If I had a few dozen here and there its not a big deal but I can literally see hundreds and hundreds. I would say just make sure to be careful when using it as you would not want to get the powder into your lungs. Also you could use some clean water with a drop of dawn to help get rid of any excess that might be clogging up your stomata. Which I was just made aware of yesterday because I think my girls might have been getting a bit clogged as well form my kelp and ewc brews.
    Another thing I was wondering about last night was since DE is basically 80% silica could someone use powdered silica the same way they use DE? IF so would I be able to just spread a nice thin layer of silica on the top of my soil to get rid of the soil mites?
  13. In the interest of full disclosure, I haven't used DE in my soil mixes for quite some time. I am on the the third or forth re-use of my soil in some instances and have no doubt that there is still some in some of my soils.

    I backed off using it when I began to use humic acid regularly because of the alumina contained in the amorphous silica (DE). Humic acid can break the bond of the aluminum from the silica and poison the plants.

    But.........when I first started using humic acid, it was leonardite and at an 84% concentration. I mixed it with water and made a liquid concentrate and may have over applied the humic acid which set off a chain of events that left my plants looking pretty unhappy.

    If you use DE, use it sparingly and be diligent about not over applying humic acid.

    @ Downgirl.........soil mites are your friend....they digest organic matter which in turn feeds smaller soil life. This link may be of some help to identify your soil mites. I love it when I water and the top of my soil comes alive with little writhing mites.


  14. Chunk their are way to many of them at this point that I feel uncomfortable in my garden. I know they are viable part of the soil food web but I dont want them over running things in the garden. When I see they are starting to journey onto the plants we got an issue!.
  15. #15 LumperDawgz2, Oct 4, 2011
    Last edited by a moderator: Oct 4, 2011
    Go with Spinosad then...............

    Get Captain Jack's Deadbug Brew (Spinosad) because it's undiluted therefore more effective than pre-mixed products.

    I forget to add Spinosad to discussions about biopesticides not because they don't work but because I don't have to venture out much of the neem and karanja deal so it slips my mind.

    Spinosad is extremely effective. Our dog gets an oral version of Spinosad (Comfortis) at the beginning of each month to prevent fleas. She started Spetember 2010 and has not had a single flea or tick. Pretty amazing colony of bacteria.


  16. #16 urlove, Oct 18, 2012
    Last edited by a moderator: Oct 18, 2012
    Spinosad makes the feeder's nervous system get over excited.
    Death by adhd !
  17. That One Stoner likes this.
  18. I got a potential gnat issue. Looks like I will be letting my soil dry up then coat the top with diatomacous earth.
  19. IME diatomaceous earth will not solve a gnat issue. try applying a thick layer of dry mulch (hey, dry leaves..) and add plenty of moving air around the soil surface. this will make it hard for them to fly around the soil looking for places to lay eggs.
    SpiritMtFarms likes this.
  20. ohh thanks.

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