Disease

Damping-off

Pythium, Rhizoctonia, Fusarium spp.

Soil fungi and water molds that rot seeds and seedling stems. Cool, wet, poorly drained media and crowded flats give them the edge.

Signs

Seedlings with a pinched, thin, water-soaked stem at the soil line that topple over.
Gaps in a flat where seeds never came up, or rotted before emerging.
Spreads outward in a patch through the tray.

Cool, wet media, poor drainage, crowded flats, low light and reused trays.

Use new, sterile seed-starting mix and clean or new trays.
Keep the mix moist but not soggy.
Bottom heat and good light for fast emergence; sow thinly so stands are not too thick.

Treatment by crop

Cultural, biological and chemical options in the order to use them, and notes written for each crop.

Identification is free. Treatment is on the Home and Pro plans.

Open in the key See plans

Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
No, only damage or discoloration
Where is the problem?
Seedlings or new transplants
What happened to the seedlings?
Stem pinched thin and water-soaked at the soil line, then they topple

Not a match? Start the key or describe what you see.

More from university Extension: search Extension pages on damping-off, or find a plant diagnostic lab through your state's Extension.