Fungus Gnats in Dieffenbachia: Dry Soil Solution

Tiny flies around a recently repotted dieffenbachia are almost certainly fungus gnats. Their larvae feed on soil fungi and organic matter, not healthy roots. The repotting likely disturbed soil and triggered adult emergence.

Why They're There

• Overwatering creates ideal fungal growth for larvae.
• Peat-based mixes hold moisture too long.
• New potting soil often contains eggs.

Simple Fix—No Chemicals Needed

1. Allow top 1-2 inches of soil to dry completely between waterings.
2. Remove saucers; never let pot sit in water.
3. Top-dress with 1/2 inch sand or perlite to accelerate surface drying.
4. Yellow sticky traps catch adults, reducing egg-laying.

If plant is otherwise healthy (new leaf growing), gnats will disappear in 2-3 weeks as soil dries. No insecticide needed. For persistent cases, a Bti (Mosquito Bits) soil drench kills larvae safely.