Soil Gnats in Herb Pots

Problems

• If you have gnat larvae in the soil of your herb pots, you will need to deal with swarms of adults that will gather around your light sources and windows. The larvae could feed on the roots of your herb plants, causing the plants to wilt.

Control

• You may control the adult fungus gnats by spraying them with a pyrethroid-based insecticide. If the larvae are killing your herbs, you may drench the soil with a microbial insecticide to eliminate them, according to Colorado State University Extension.

Prevention

• To prevent gnats from taking over the soil in your herb pots, never reuse potting soil. Fungus gnats are attracted to over-watered soil that is very moist, so take care not to let your herb pots get too wet, the authors of "Container Gardening for Dummies" advise.