✍️ Sonia Pardasani, Co-founder BageechaBox | 🕐 7 min read | Troubleshooting Guide
How to Prevent Mold on Microgreens
Mold is the most common problem in microgreens growing — and it's almost always caused by one of three things: too much water, no airflow, or seeds sown too densely. Here's how to prevent and fix it.
Prevention — The 5 Golden Rules
- Bottom water only — never mist the canopy after germination. Wet leaves = mould.
- Correct cocopeat moisture — moist, never soggy. Press test: water should not drip.
- Airflow at all times — keep a window open or a fan circulating near the tray.
- Don't overcrowd seeds — seeds should be close but never overlapping.
- Clean trays between batches — wash with soap, dry fully before reuse.
Root Hair vs Mold — How to Tell
Root hair (normal): Fine white threads close to the stem base only. Uniform pattern. No smell. Does NOT spread upward.
Mold (problem): Cottony fluffy patches spreading upward and across the surface. Musty or sour smell. Spreads visibly over 24–48 hours.
If Mold Appears — Act Immediately
- Stop all top watering immediately — bottom water only
- Increase airflow — point a fan to circulate air around the tray
- Sprinkle cinnamon (dalchini) powder lightly over affected area — natural antifungal
- Reduce watering frequency for 2–3 days
- Discard the tray if mold covers more than 30% of the surface or smells strongly
Monsoon Extra Care
July–September is the hardest season. Humidity above 70% means mold spores are everywhere. Harvest 1–2 days earlier, keep fans running continuously, and stick to fast-growing varieties like Radish and Mustard.