✍️ Sonia Pardasani, Founder BageechaBox | 🕐 4 min read | 🔧 Troubleshooting
Quick answer: The most common pest on indoor microgreens in India is the fungus gnat — tiny black flies hovering over the tray. They breed in constantly wet growing medium. Let the surface dry slightly between waterings, switch to bottom watering, improve airflow, and use yellow sticky traps nearby. Never spray pesticides on microgreens — you eat the whole seedling within days.
Microgreens grow so fast that pests rarely have time to cause real damage. But a cloud of little flies around your tray is unpleasant — and it's a sign that something in your setup needs adjusting.
Identify the Problem
| What you see | Likely cause |
| Tiny black flies hovering over the tray | Fungus gnats — medium staying too wet |
| Small green or black insects clustered on stems | Aphids — more common on balconies |
| Ants around the tray | Attracted to soaked seeds or moisture |
| White fuzz spreading on the medium | Not a pest — likely mould; see our fungus guide |
Getting Rid of Fungus Gnats
Step 1 — Let the surface dry a little
Gnats lay eggs in constantly wet medium. Water only when the tray feels light.
Step 2 — Switch to bottom watering
Watering into the bottom tray keeps the top surface drier, which gnats dislike.
Step 3 — Hang yellow sticky traps
Place a trap near (not touching) the tray to catch adult flies and break the breeding cycle.
Step 4 — Improve airflow
A small fan dries the surface and makes the area less inviting.
Step 5 — Start the next tray clean
Wash trays between grows, and sterilise cocopeat before every reuse — see our cocopeat reuse guide.
Aphids and Ants
- Aphids: move the tray indoors, rinse the affected greens gently, and harvest early if needed
- Ants: stand the tray on a plate with a little water around it, and keep soaked seeds covered
What Not to Do
Don't spray chemical pesticides — or even home sprays you're unsure about — on microgreens. You harvest and eat the whole seedling within days, so anything sprayed on it ends up on your plate. If a tray is badly infested, it's safer to compost it and start fresh.
⚡ Key Takeaways
- Fungus gnats mean the medium is staying too wet
- Bottom water, let the surface dry slightly, add airflow and sticky traps
- Never spray pesticides on microgreens
- Badly affected tray? Compost it and start clean
Frequently Asked Questions
Q: What are the tiny flies around my microgreens?
Usually fungus gnats. They breed in constantly wet growing medium. Let the surface dry slightly and switch to bottom watering.
Q: Are microgreens with fungus gnats safe to eat?
Gnats live in the medium, not on the leaves. Harvest cleanly above the cocopeat and rinse before eating. If the tray also shows mould or smells sour, discard it.
Q: Can I spray neem oil on microgreens?
We don't recommend spraying anything on microgreens, because you eat the whole seedling within days. Fix the moisture problem instead.
Q: How do I stop pests coming back?
Bottom water, keep air moving, wash trays between grows and sterilise cocopeat before every reuse.
📚 Further Reading
🌱 Start fresh with a clean setup
Two-tray sets for bottom watering and fresh cocopeat discs.
Shop Trays Cocopeat DiscsAbout the Author
Sonia Pardasani
The Microgreen Lady · Delhi/NCR
From the classroom to award-winning urban farmer — Sonia spent years teaching before dedicating herself to mastering the science of microgreens in Delhi’s extreme climate. What started as a personal health journey became a mission to train 2,000+ home growers and entrepreneurs across India. Honoured by the public as the "Microgreen Lady," Sonia now runs BageechaBox, guiding home growers and commercial farmers to grow consistently, profitably, and sustainably.