Distinguish mold from root hairs before panicking

White fuzz at the base of microgreen stems is almost always root hairs, not mold. Root hairs are a normal, healthy sign of vigorous growth. Actual mold looks and behaves differently.

How to Tell the Difference

• Root hairs: Fine white filaments radiating evenly from the stem base. They appear on most seedlings uniformly and disappear when misted with water.
• Mold: Cobwebby or cottony patches that appear randomly on the soil surface or on dead seeds. Often gray, green, or blue-tinged. Doesn't disappear when misted. May have a musty smell.

Tips

• Mist the suspect area lightly — root hairs collapse and become invisible, mold stays
• Root hairs are most visible on radish, broccoli, and brassica microgreens
• If it is mold, increase airflow, reduce watering, and remove affected areas
• A small amount of surface mold can be cut away — the greens above are usually fine