Plant Parenting: How to Recognize Damping Off in Seedlings

January 10, 2020

Damping Off Disease

Nothing is more frustrating than to have your seemingly healthy seedlings suddenly succumb to disease. Damping off is a fungal disease caused by a combination of pathogens: Rhizoctonia, Pythium, or Fusarium fungi.

While older seedlings and transplants can typically fend off the fungi, germinating seeds and young seedlings are particularly susceptible.

Conditions were too wet and dark when these microgreen seedlings were beginning to germinate, and some mold began to grow on the seeds. I removed the humidity dome for a day or two and increased the light and was able to save this crop.
PC: Leslie F. Halleck

Recognize Damping Off

Signs your seedlings are suffering from damping off:

  • Your seeds never emerge from the soil
  • The cotyledons are discolored or look waterlogged or mushy
  • The seedling stem becomes thin and water-soaked looking
  • The new leaves wilt or look discolored
  • You find no roots on your seedling or the roots are discolored and stunted
  • White mold-like growth develops on seeds or seedlings in high humidity

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