Fungus Gnat Prevention

Credit: Terry Guscott

If you notice fungus gnats, your first step should be to ensure you are not overwatering. Letting the surface dry out between waterings can go a long way toward controlling the problem. If that fails, try applying Hypoaspis, a common predatory mite of fungus gnats, which will attack the juvenile stages of fungus gnats and suppress their numbers.

Available where beneficial insects are sold, these mites are simple to use, natural and inexpensive. To apply Hypoaspis, first lightly water the soil surface of the infected plant.

Place 5 mL (per 15-centimetre pot) of the Hypoaspis and their carrier (commonly peat/vermiculite) on the soil surface. Keep moist, and within a week, the eggs will hatch and seek out the gnats.