Fungus Gnat Control: Target the Larvae, Not the Flies

Lifecycle & Control

Adults live ~5 days. Larvae in top soil feed on decaying matter (bark, dead roots). Overwatering and bark-rich mixes fuel them.

Effective Tactics

• Dry soil surface; add coarse coir, sand, or diatomaceous earth (sharp edges kill larvae).
• Potato slices on soil trap larvae—discard daily.
• Knock-Out Gnats (Bti) for heavy infestations.
• Detection: water lightly, watch for tiny larvae swimming.

Prevention

Use sterile, bark-free, perlite-rich mixes. Let soil dry well between waterings. Red wine traps catch adults.