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One simple trick to help prevent fungus gnats from laying their eggs is to block their access to the soil. You can do this by putting a shallow layer of pebbles, marbles, shells, aquarium gravel, or other decorative stones on top of the soil.
Sticky traps really do work—not to resolve the underlying issue that allows fungus gnat larvae to thrive in your plants’ soil, of course, but at least to reduce the amount of fungus gnats buzzing around your plants.
If you’re having trouble getting rid of fungus gnats but don’t want to jump to using heavy pesticides, insecticidal soap may be a helpful solution.
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