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  • Gnats. I declare a cautious victory.

    Gnats. Combined with overwatering, I was ruined in my first attempt at growing cuttings. However, I have some little figlet survivors, and they're starting to put out new growth again. As a bonus, I haven't seen a gnat in 2 days. I thought I would share how I got rid of them, for anyone who was interested.

    1) Fly traps. The yellow sticky ones. I got these early on, which curbed the infestation. I put 10 of them up about 2 months ago, and each one has between 50-300 gnats stuck to it. Can you imagine if I hadn't used them?

    2) Fly traps weren't enough. I bought some gnatrol. 20 bucks online, and its enough to last years. I started watering my cuttings with it.

    a) Give the gnats a new target...a deadly one. I took some sphagnum left over from rooting, and dampened it heavily, and coated it with gnatrol. I then lined my bins with it. The gnats love it, which is a shame for them, because their larvae can't survive in it (being coated with gnatrol and whatnot), and I also let it dry out in between wetting it, which desiccates any larvae in there.

    b) Water only from the bottom with gnatrol infused water. The little jerks still get in the holes at the bottom, but this helped resolve my overwatering issue. You see....I couldn't treat the cuttings with gnatrol properly without drenching them...kind of a "pick your poison" scenario. Watering from the bottom only seemed to help immensely, as the roots could still find some less wet places, if they needed, and the gnats quit going through the top, since the top inch or two of potting mix was dry.

    3) Sevin dust. I took my 2 most infested cuttings, and sprinkled a touch of this stuff on the top. Within 24 hours, no more gnats were flying out of them (at least out the top).

    4) Thumbs. Every morning and evening I took out my cuttings, tapped on the sides gently, and watched a few gnats scurry out. Smashed them all with my thumbs. The first day was terrible...20+ gnats. Then 15. Then 10. Each day was less and less. So very satisfying to kill the little scum-suckers.

    Overall, I'm sure that prevention is WAY easier than all of this. Also, I'm sure that I haven't completely destroyed the infestation, but I've severely crippled it at least. However, if you find yourself with a gnat problem, these steps helped me immensely. 2 weeks ago I was sure that I was going to lose all my cuttings...they were all dropping one by one (I went from 20+ to less than 10), and none were growing actively (tops or roots). In fact, most were actively dying. Now several are rooting like mad again, and 2 of them are actively putting out green, with another breaking bud.
    Last edited by brettjm; 03-04-2015, 05:50 PM. Reason: Changed "sevendust" from a hard rock band to an insecticide. They're great live, BTW.
    Brett in Athens, GA zone 7b/8a

  • #2
    Way to go and kill those gnats Brett! I definitely advocate the use of sevin for gnats.
    Eatonton, GA zone 7b/8a


    • #3
      Multi-pronged attack. Congrats on your success. Reminds me of flea control on the cats - before the magic drops were invented.
      SoCal, zone 10.
      www.ourfigs.com Invite your friends.


      • #4
        Congrats and thanks for sharing those tips.
        Otmani - Dallas, TX - Zone 8a
        Wish List: Col de Dame Blanche, Brogiotto Bianco, Sicilian White, Panache


        • #5
          My suggestion is don't wait for the problem. gnatrol is cheap and as you state once you have the problem, It's hard to treat without excessive moisture. Use gnatrol from day 1 when you moisten your potting mix, and everytime you water use it.
          Phil North Georgia Zone 7 Looking for: All of them, and on and on,


          • drphil69
            drphil69 commented
            Editing a comment
            I wet out the potting mix with gnatrol water at high strength as a preventative. If I see even one gnat I water with gnatrol for the next few waterings, but pre-treatment seems to work well. I've been using MG seed starter mixed 1:2 with perlite for cups.

        • #6
          Physical, chemical, and biological warfare - it's the way to go. The only thing you're missing is psychological warfare! Now, how do we get inside the heads of these little gnats and psych them out?
          Jim -- Central NJ, Zone 6b


          • #7
            But seriously, 2 days is too soon to declare a total victory. You're doing all the right things, but don't let your guard down. There are surely still some eggs, larva and pupa in the soil waiting to emerge, as well as some elusive adults. The cycle is difficult to break without constant diligence. Keep up with the gnatrol and sticky paper. Also, for psychological warfare, you can try cursing. It won't affect the gnats at all, but it will make you feel better ;-D
            You may only view thumbnails in this gallery. This gallery has 1 photos.
            Jim -- Central NJ, Zone 6b


            • #8
              Psychological warfare? I have not considered this. One of the professors in my department studies "emotions" in fruit flies...more specifically neuron activity and responses in fruit flies given various stimuli, but in his talks me brings up emotions. I should consult him for what would be most damaging to the sex drive of fungus gnats.
              Brett in Athens, GA zone 7b/8a


              • Needaclone
                Needaclone commented
                Editing a comment
                Yes -- I strongly encourage you to take it up with your professor. We need all the help we can get! Plus, it may lead to a PhD thesis in your future -- "Disruption of the Bradysia spp. Life Cycle through Emotional Manipulation."

            • #9
              I'm glad you got the gnats under control, it can be agiant pain, congrats.

              I had a small gnat problem, i add a couple SunDews to one bin, a Venus Fly Trap to the other along with a couple baby jumping spiders in each.... problem solved!!!!

              At this time, everything is so happy that the Venus Fly Trap is putting up a bloom stock.
              Scott - Colorado Springs, CO - Zone 4/5 (Depending on the year) - Elevation 6266ft

              “Though the problems of the world are increasingly complex, the solutions remain embarrassingly simple.” – Bill Mollison


              • #10
                wow, thanks for the information. I just put 2 inches of sand on top of the soil in my pots. Hopefully that gives the gnats nowhere to lay their egss.

                I have mosquito dunks....has anyone ever had success with it against gnats?


                • #11
                  "...little jerks..."

                  I've used the BT bits, and there are people who use the dunks, crushed or dissolved in water.
                  I think the bits worked better than Gnatrol for me last year, but it's kind of hard to know for sure.
                  This year, I went with Harvey's Promix approach. Six weeks in and not a single gnat.

                  Nice work bringing the cuttings back from the brink.


                  • #12
                    I noticed that the gnats completely ignore the pots with Napa floor dry but really love the peat based soils. I made a large amount of mix of the floor dry + perlite + coco and have not seen a single gnat around for a month. The pots are outside with newly rooted cuttings (ie the roots are still tender and juicy). It could be my imagination but I hope this may mean something. The mix is also very airy and the cuttings love it.
                    Note: the floor dry has very faint hydrocarbon smell.
                    USDA z 10a, SoCal. WL: Boysenberry Blush


                    • #13
                      I got a tip for gnat control from a member which is simple safe effective and also helps wick moisture from the soil so will help with overwatering. 2inch sand on top and placing the pot/cup containers bottom drain holes in sand as well. They can't get threw the top or bottom then.
                      Zone 5 Chicago IL Wish list:
                      1) Rest peacfully Amico Bello Buddy 👼🏼.
                      2) This weeks ebay auctions.