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Controlling Fungus Gnats Indoors in Soil.

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    you can use sand on the top of the plants and i also agree gnatrol and sticky traps work well


      I'm sure the usual suspects will stop in and explain how they kill fungus gnats (I've used Gnatrol with good results) but the point of this thread is how to avoid them in the first place. Simple steps in my first post.

      Now that we've hit our first frosts of the year, I can report that I made it through the gnat season with zero infestations. This is the first time in several years of growing that I haven't had to kill an infestation. Got a few on the yellow sticky traps but they never established a breeding cycle.

      Now back to OT favorite FG killing approaches ...


        For prevention I keep away from using any soil that is rich in moss and make the 1-2" top layer of a mix of perlite and vermiculite.
        For treatment I've used a spray of hydrogen peroxide with regular water, it kills (burns) the gnats and larvae and can be used up until harvest date with no ill effect to the plants or the smoker and is inexpensive. Just make sure to let the plants dry out before the dark period, so lots of ventilation and air extraction is the way to go.


          bookin this thread.
          last year I had a terrible problem with these heartless little creatures.
          Bleach in the P-traps might help some . seems to be where they start.


            Tanlin...will wipe out an infestation fast. Also let them pots dry out between waterings. And always hang sticky traps whether you have a problem or not. Peace


              Originally posted by macdiesel View Post
              Fungus gnats DO come in store bought soil. Crumble mosquito dunks and sprinkle on soil=problem solved
              I powder mosquito dunks (mortar and pestle) then I add some as I mix my "Foxfarm Ocean" / "Palm and cactus" mix. I wanted to leave them no safe haven to reproduce (top or bottom) in the pots and cups.
              2 parts Foxfarm
              1 part palm and cactus mix.

              Originally posted by razor ridge View Post
              neem meal in your soil done deal
              Next I toss in some Neem seed meal and mix it all together in a bucket.
              I sprinkle on just a touch of water (if the mix is really dry) and close the bucket.

              I finally got this mix in everything in my clone / mom box and the gnat population seemed to be dropping so I wanted to know how it works.

              Test time.
              Yesterday I took pics of my yellow sticky traps after putting in brand new ones.

              These set right over the soil like a little tent.
              Many a gnats first foray into the world were suddenly and abruptly terminated.

              Today, 24 hours later and I see 4 little bitches stuck on the traps.


              From below.
              A little dirt where its edge touched the soil, but looking good.

              I'll see how it goes through the week but I'm stoked.

              That deserves a vape

              Vape on.
              Just because your paranoid
              Doesn't mean they aren't out to get you.


                Nice thread, also using Beneficial Nematodes in ur mix will help keep them under control, never had a real problem until this year with them, and didn't catch it until their little larvae asses ate the roots and killed some seeds I was germinating. Was thinking about adding sand on top as a layer of defense, but so far, yellow sticky traps, and the nematodes are keeping it under control, still have a few flying, but it's nothing to write home about. But will one day try the sand to see if that really helps or not.
                Njoy the Grow


                  The sand thing is a PIA.
                  Just put dryer sheets on the soil surface.
                  They shield the soil from egg laying and hatching.
                  But the big deal is, they actually REPEL the flyers.

                  Cleared my heavy infestation 11 years ago.
                  I change them out for fresh ones every 30 days or so.
                  They are inexpensive, harmless to humans and pets, and very effective.
                  And before you ask, they do not affect the scent, or flavor of my meds.
                  I use Kirkland "lightly scented" because Bounce sheets reek and might affect scent.
                  "It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."
                  - Mark Twain

                  "Plants do things for a reason, they don't just decide one day to get root rot or act funny." -Weedhound

                  A prudent question is one-half of wisdom. -Francis Bacon

                  A wise man is superior to any insults which can be put upon him, and the best reply to unseemly behavior is patience and moderation. -Moliere

                  You're behaving as if there is no hope. Someone musta told you you were hopeless and you believed them! That's it, isn't it? What you believe about yrself rests on a pile of someone else's shit! - Teddybrae


                    Quark nailed it. Stop over watering, no more f.n.
                    Of cause if you encounter the Borg you have to over water, but otherwise, dry your soil out.
                    When as men, our only guide to right and wrong is the ability or inability to act, we cannot truly call ourselves men.

                    Copyrights on all photographic work are reserved


                      This is still working flawlessly for me in coir. Used to have at least one major infestation per year, haven't had one since I started doing this. Just want to add another tip. After a few cycles of use, the fiberglass mesh can get warped and distorted. Take a stack of the same sized pieces and drop them into a pot of boiling water for a few minutes. Fish them out and put them between two flat surfaces with a little weight added. As soon as they cool, they are back to flat and like new. I've been using the same pieces of mesh since I started using this technique. Same pea gravel too. Virtually no added costs, once you get set up.


                        Time for an update.

                        Hi all,

                        4 months ago I found this thread and bought some mosquito dunks to see if I could de-gnat my grow area. They were everywhere. The key word there is "were" .
                        I put a new sticky trap in the flower room 3 months ago (1 month after starting the dunks) and no more gnats! I open the door and no more flurry of disturbed bugs. Watering, trimming, and just spending time with Judy (all my girls are Judy) is so much nicer without gnats.

                        There is more dust and debris than critters on the trap . What critters that got in while I had the door open got caught and the dunks stopped them from breeding.

                        With the pests controlled I can get back to worship.
                        All hail the mysteries and joy of Judy.

                        It's more than just a belief, it's a way of life.
                        Vape on kids.
                        And thank you all for your input and ideas.
                        Just because your paranoid
                        Doesn't mean they aren't out to get you.


                          You can also sprinkle cinnamon around your plants. Just my 2 cents
                          Happy Gardening.

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