Rescue playbook
How to get rid of fungus gnats in houseplants
Tiny dark flies around the soil? Dry the top inch and break the breeding cycle — don’t drown the pot.
Small dark flies around soil usually mean fungus gnats. Dry the top soil and break the breeding cycle.
What to look for
- Tiny dark flies hovering near soil or windows
- Larvae in moist potting mix (thin, white, dark-headed)
- Soil that stays wet for days after watering
- Seedlings or weak plants looking stressed from root nibbling
Day-by-day plan
Day 0
Let the top inch dry
Skip watering until the top 1–2 inches of mix feel dry. Gnats breed in constantly damp surface soil.
Day 0
Yellow sticky traps + optional top dress
Place yellow sticky traps near the pot to catch adults. Optionally scrape or replace the top half-inch of soil, or add a thin sand/gravel layer.
Day 7
Check adult fly count
If traps are still busy, continue dry-surface watering and refresh traps. Consider a biological drench labeled for fungus gnat larvae if available.
Day 14
Confirm the cycle is broken
Adults should drop off within 1–2 weeks once surface moisture is controlled. Resume normal watering only when the mix needs it.
Safety
Avoid flooding the pot “to drown them” — that usually makes breeding worse. Follow label directions on any biological product.
See a nursery if…
Flies persist after three weeks of dry-surface care, or roots smell foul / plant collapses (possible root rot overlap).
Houseplant-only note
This guide is for household houseplants — not human or animal medical advice, and not a substitute for a nursery or plant pathologist when a plant is seriously declining. Full disclaimer.
Need reminders while you treat?
Rootline can keep a treatment plan and care schedule on your phone — free crisis playbooks included. Soft launch on iPhone.