Damping Off is a horticultural disease or condition, caused by a number of different pathogens that kill or weaken seeds or seedlings before or after they germinate. Sometimes seeds my start to germinate and grow, but within a few days they become water-soaked and eventually die.
HOST PLANTS: This disease affects a large variety of common plants, mostly in the seedling stage.
SYMPTOMS: Several fungi can cause decay of seeds and seedlings, including species of Rhizoctonia, Fusarium and Phytophthora. However, species of the soil fungus Pythium are most often the culprit. Damping off typically occurs when old seed is planted in cold, wet soil and is further increased by poor soil drainage. High humidity levels, rich potting soils, and planting too deeply will also encourage its growth.
FAVORED ENVIRONMENT: Fungal spores live in the soil, and are primarily a problem in seed beds. They can be transported on garden tools and in garden soils taken into the house or greenhouse.
DAMPING OFF CONTROL: There is no cure for plants that already have damping off, however you can easily prevent the problem by providing good air circulation. A small fan or simply cracking the lid of the germination tray will suffice. The biological fungicide Mycostop may also be used as a seed treatment to prevent seed or soil-borne diseases. Other steps for preventing damping off include the following: