Prevent and treat mold with airflow and hydrogen peroxide

Mold is the most common microgreen problem, caused by high humidity, poor airflow, and overwatering. Prevention is far easier than treatment, but caught early, mold can be managed without losing the tray.

Prevention

• Run a small fan near trays after the blackout period
• Switch to bottom watering to keep leaf surfaces dry
• Don't overseed — overcrowded trays trap moisture
• Use clean trays and fresh growing medium every cycle

Treatment

1. Remove visibly moldy sections immediately with scissors
2. Spray affected areas with 3% hydrogen peroxide diluted 1:10 with water
3. Increase air circulation immediately
4. Reduce watering frequency

Tips

• Food-grade hydrogen peroxide is safe and breaks down into water and oxygen
• If mold covers more than 25% of the tray, compost it and start over
• Pre-soaking seeds in a diluted hydrogen peroxide solution (1 tsp per cup of water) reduces mold spores