well I am conducting war on gnats. I believe the source of the problem was using Miracle Grow moisture control soil. This stuff stays wet it seems. What I have done is: 1) to scrap away as much of the top soil as I could and replace it with a better draining soil 2) with reduced watering and letting the soil get as dry as I could without stressing the plants, I watered with a 4:1 hydrogen peroxide and water ( 1 part to 4 parts water) 3) put a bowl of apple cider vinegar on the floor (was not very effective in attracting them - I killed far more by clapping them in air or squashing on floor) 4) put lots of yellow sticky trap paper all around (very effective as they are def. attracted to yellow) Obviously excessive moisture is the root problem and breaking the life cycle of these things and not letting conditions return that allowed a breading haven is paramount I would think. Currently I am only seeing a couple around now as I think I am getting the upper hand on the battle. It doesn't seem like they hurt anything as all plants are growing like mad and hopefully since I started fighting back hard as soon as I saw a couple, hopefully this battle has not harmed the plants. Plan on continuing doing what I have and continue to mix 1 part hydrogen peroxide to 4 parts water when watering and continue to leave the sticky paper out and I assume once I have not seen any more for a week+ straight, then I think I can assume the war is over. Thoughts / suggestions of something I have not tried or thought of?
just cover the soil.... an inch of garden sand will block them (just be careful when watering so you don't leave holes in the sand) panda-poly or just a trash bag cut to the shape of the planter top with a slit and star-cut pattern where the stalk comes up will block them from the soil too (I do this if they come around) keep them and reuse as you need them star-cut pattern is like this ---------x- and add a fan to keep the air moving
I've dealt with gnats for a long time and they can have multiple sources. Right now they're feeding and living off the dead roots in my self-watering system, they can also get by on any algae that forms on perlite or rockwool, drains, stored soil, etc. But they're not fucking with my soil and here's why: Things that actually work at keeping them out of soil IME cost $10-$20 each. Neem meal IMO is the best gnat deterrent because it works on other bugs such as spider mites AND feeds your plant while it's working, is 100% effective for me. Gnat nix is puffed glass that shreds any insect that tries to crawl through it, and is applied to the top layer of soil, this also was 100% effective for me. Diatomaceous earth works the same as gnat nix. Spinosad is not a chemical pesticide, uses specific bacteria that kill gnat larvae and is popular among the organic growers. Mosquito Dunks from home depot are similar to spinosad but use a different bacteria, it'll kill most of the gnats but it's not designed for them and there will be a few survivors that come back with a resistance. Waste of $10 IME. Those cheap and free methods didn't work for me. Cider traps, sand, potatoes, they ignored them all. Sticky traps work on the adults but that won't stop the approaching swarm if you don't kill their babies. Chemicals such as No-Pest strips work 100% too, but I don't fuck with chemicals unless it's a pyretherin that breaks down within 24 hrs (commonly found in fruit/vegetable pesticides) and even that's a last resort. Neem meal: http://www.everwoodfarm.com/Down_To_Earth_Organic_Fertilizers/Organic_Neem_Seed_Meal Spinosad: http://www.gardeners.com/buy/spinosad-insect-control-spray/38-991RS.html Gnat nix: https://www.sunlightsupply.com/shop/bycategory/growing-media/growstone-gnat-nix Diatomaceous earth: http://www.homedepot.com/p/Safer-Brand-4-lb-Diatomaceous-Earth-Ant-and-Crawling-Insect-Killer-51702/202743025
most air comes from the bottom and they release something else through the top of the roots Sent Via My Pokedex http://forum.grasscity.com/index.php?/topic/1305920-Kushgodrex%27s-First-Grow