Fungus Gnats in Corn Plant Soil: Repot to Eliminate the Source

The Real Problem Isn't the Adult Gnats

Fungus gnats (often called "knats") breeding in potting soil indicate overly moist, organic-rich soil – their larvae feed on fungi and root hairs. The plant's decline is likely from root rot caused by the same conditions, not the gnats themselves.

Complete Soil Replacement Is the Cure

1. Remove plant from pot
2. Gently shake off all old soil
3. Clean pot thoroughly (bleach solution if reusing)
4. Add 2 inches of drainage material (gravel, perlite)
5. Repot in fresh, well-draining potting mix
6. Water sparingly until established

Future Prevention

• Let soil dry 2-3 inches deep between waterings
• Use pots with drainage holes
• Yellow sticky traps catch adults
• For foliar pests, use isopropyl alcohol spray

Corn plants (Dracaena fragrans) are tough – fresh soil and proper watering usually trigger a full recovery.