Damping off

A soil-borne fungal problem that makes young seedlings collapse at the soil line, thinning and toppling soon after germination.

Seedlings flop over with a pinched, water-soaked stem at soil level; whole trays can be lost quickly.

There is no rescue for collapsed seedlings, remove them. Improve airflow and reduce watering for survivors.

Use fresh sterile seed-raising mix, clean punnets, water from below, and avoid sowing too thickly in cold damp conditions.