Fungus Gnats, Repotting Q.

Discussion in 'Sick Plants and Problems' started by StankTree, Dec 15, 2011.

  1. Recently i've noticed some signs of fungus gnats in my veg room. Doesn't seem like a very serious infestation- caught about 5 gnats total over the course of a week on my sticky traps.

    Some time this week i'm going to re-pot them into larger pots and move them into flower. My plan is to wash the roots in a bath of water, Neem oil, and hydrogen peroxide before putting them in their new pots.

    What do you guys think, will that wipe out those buggers?
  2. #2 OhioStateBuckeyes, Dec 15, 2011
    Last edited by a moderator: Dec 15, 2011
    the oily content of the neem can negativley impact your roots. i wouldnt mix the H202 with the neem, either. ive NEVER had ANY success with neem & fungus gnats.

    H202 will kill all larvae and gnats in your soil, but me personally, i wouldnt use H202 unless all else fails. i like to have a bottle of hydrogen peroxide sitting around JUST IN CASE somthing extremley bad happens. i havnt used H202 in like 6-7 months. H202 can burn your roots if used too frequently.

    fungus gnats are more of a neusiance than pest to your plants. flying fungus gnats will not eat any part of your plant. their larvae, however, eat roots in about the first 5 inches of soil. dont forget, gnats love the drainage holes of your pot! their larvae can thrive there, too. they are not as destructive and dont eat as much as spider mites, aphids, whiteflies, thrips, leaf miners, budworms, and the list goes on.

    however, they are still a pest in your garden and even if you cannot kill them all, it is best to keep them controlled.

    what you should do, is go to home depot and get one of those cheap mosquito dunks for ponds, a big waxy looking cube. i think there only like 5 bucks a piece.

    you want to find one with Bacillus thuringiensis as your only active ingredient. im not sure of all the brands out there, and idk what else they put in there. you want to stay away from harmful chemical pesticides. B. thuringiensis is a naturally occuring bacteria that kills fungus gnats, mosquitos, and black flies (house fly).

    when you get the cube, shave off a little bit with a knife and place the sliver of it in your soil. do this with each pot.

    they sell B. thuringiensis at the grow stores under the product named Gnatrol. Gnatrol works great too, but it is expensive. i think the cheapest route would be the mosquito dunks.

    spinosad (what you give your dogs) works great for gnats, too.

    another thing i recommend is the fungus Beauveria bassiana. it is a parasitic fungi that feeds off of soft bodied insects like gnats, aphids, spider mites, thrips, etc. if you wikipedia Beauveria bassiana, you can see the fungi in action killing a grasshopper. The product i use that contains this is called BotaniGuard.

    have fun killing some gnats!

  3. or put an inch of sand on top of the soil

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