December 7th, 1963
Plant Knowledge Level
I am plagued by fungus gnats. Help my plants. I even bought a couple from the Sill and I’m afraid of infecting them. Is there any thing that I can do to get rid of them?
I've had some luck with using diatomaceous earth mixed in with the potting soil to prevent the larvae from surviving after hatching.
Hi Marie! Fungus gnats usually proliferate when the soil is too wet and generates excess fungus which is what they feed on, mostly caused by over watering plants. You can get a product known as mosquito bits and place it in the soil as it will attack the larvae! Further providing the standard yellow fly traps to capture the adult gnats and keep them from reproducing! Both of these can easily be found online. If the infestation is heavy, I'd recommend discarding all of the soil and replenishing your plants with new soil. You'll then want to place sand as a top dressing (layer about 1-2 inches thick) to trick the adult gnats into thinking the soil is actually dry- which prevents them from laying more eggs in the soil, and will eventually die off. You'll still want to place fly traps around the plant so that they still capture the adult flies looking for a host!
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