Damping off is a widespread and troublesome disease that affects seeds and young seedlings. A broad range of fungi and fungus-like organisms can cause damping off. Quite often the spores lay dormant in soil and compost for prolonged periods. Due to a large number of organisms that cause it, damping off can affect an enormous range of vegetable and ornamental crops. Damping off is most likely to occur when seedlings are sown under humid conditions with bad air circulation. Young plants grown indoors or under glass are of particular risk, especially if seeds are sown too thickly.
Overly moist growing media. Humid growing conditions. Poor airflow. Drying out of growing media.
Seedlings fail to germinate.
Seedlings dying often is circular patches.
Shriveled top growth.
Roots rotten away.
Seedlings falling over.
White mould on leaves of larger plants.
There are no biological treatments.
Chemical treatment is ineffectual due to the speed at which the seedlings become beyond the point of saving.
The life cycle depends on the species of pathogen.
Sow seeds into fresh compost, taking care to not overcrowd seeds. Practise good plant hygiene. Don't use containers to plant seedlings which have previously contained plants with damping off. Always wash/ sterilise tools, pots and trays following use. Make sure pots and tools have dried before reusing. Ensure seedlings have sufficient air circulation and avoid overly humid conditions. Use tap water for irrigation, unless you can ensure rainwater has not been contaminated by organic matter.
Affects a wide range of plants. Most seriously in bedding plants.