How do I rid my houseplants of soil gnats?
Answer
Gnats in the soil of plants are harmless, but irritating to people. They feed on organic material in the soil. They thrive in wet soil and can come into the house on fruit or in soil of plants. Do not overwater and you will reduce the number of gnats. There is a BT formulation labeled Gnat Control that is safe and will eliminate them. There are commercially available traps available: Gnat Stix, Terro Fruit Fly Trap, and Fly Web Fly Trap. There are also home remedies available on the web, just Google Gnats in house.
Bringing in plants in the house in fall may increase the quantity of gnats in the house and is a good time to use a soil drench or other control to kill them off.