Fungus Gnats in potting soil - Ask Extension
I got fungus gnats from my potting soil. I have treated all my potted plants with Mosquito Bits. But what about my remaining potting soil? If I put my...
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Fungus Gnats in potting soil #678377
Asked December 18, 2020, 10:40 AM EST
I got fungus gnats from my potting soil. I have treated all my potted plants with Mosquito Bits. But what about my remaining potting soil? If I put my bags of potting soil outside in this freezing cold weather will the cold kill them off?
Ramsey County Minnesota
Expert Response
Some species of fungus gnats can survive freezing temperatures. Two solutions I would suggest are letting the potting soil dry out completely (it's often moist in the bag) or bake at a med temp (350) for about a half-hour. It will be a bit smelly, but will definitely kill anything living in the soil. If you need to use the soil soon, I would go with the baking solution. The good thing about fungus gnats is that they won't hurt our plants, they're just irritating.
