Fungus Gnats in Houseplants: Check the Soil First
Original concept illustration, not to scale. In this guide What signs point toward fungus gnats? Why does watering matter? Should you replace the potting mix? Should you use an insecticide straight away? Frequently asked questions Work through one pot rather than treating the whole room What this check cannot tell you Related guides Sources Small flies around a pot can be frustrating, but not every tiny fly is the same pest. Iowa State Extension identifies overwatered houseplant soil as a common breeding place for fungus gnats. Start by checking the plant and its growing mix, not by spraying the whole room. What signs point toward fungus gnats? Watch the soil surface when watering. Iowa State notes that small flies running over the mix and up the pot's sides may be breeding there. A fly on a window or screen alone does not identify the source. Inspect nearby pots before deciding which plant needs attention. Why does watering matter? Fungus gnat larvae feed on fungus in decaying org...