Treatments
Every treatment, side by side
Written by Mustafa Ayan Fact-checked against university extension/IPM sources Last reviewed: September 19, 2026
No single method finishes a fungus gnat infestation alone — each one below reaches a different stage of the life cycle. The full guide explains how to stack them; each card here links to complete, step-by-step instructions.
Most important · Ongoing
Let the soil dry
Fungus gnats breed in constantly wet mix. Let the top 1–2 inches dry between waterings and you remove their nursery.
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Adults · 5 minutes
Yellow sticky traps
Place yellow cards at the soil surface to catch egg-laying adults. Traps monitor the infestation — they do not finish it alone.
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Best-supported larvicide · Per product label
Bti (Mosquito Bits)
Bacillus thuringiensis israelensis is a bacterium that specifically targets fly larvae. Use a product labeled for fungus gnats and follow its rate and reapplication instructions.
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Optional — use cautiously · 10 minutes
Hydrogen peroxide drench
A diluted peroxide drench is a common household suggestion, but extension guidance on it is mixed. Not part of the default plan — read the cautions before using it.
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Keep them gone · Habit change
Prevention that actually sticks
Bottom watering, a sand or grit top-dress, sterile mix, and empty cachepots. Keep monitoring for a couple of weeks after adults stop appearing.
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Not sure where to start?
Start with identification, then find the likely breeding source, then manage moisture for that specific plant, then monitor with sticky traps — that alone resolves many light cases. Add a labeled Bti product if moisture control and traps aren't enough on their own, and troubleshoot if activity doesn't decline. The 7-Day Starter Plan turns that into a day-by-day checklist.