Fungus Gnat/ Fly Infestation from Unfinished Compost

Compost Heat Failure

Immature compost harbors fly eggs. When used as topdressing indoors, they hatch into fungus gnats, then house flies.

Only Fix: Complete Soil Replacement

1. Remove all soil from pots.
2. Wash pots with bleach solution.
3. Repot in sterile potting mix.
4. Quarantine plants 2 weeks.

Prevention

Only use fully finished, hot-composted material. Test: it should smell earthy, not sour, and be uniformly dark.