Damping Off Disease

Your tiny seedlings looked perfect yesterday, full of hope and promise. This morning, stems are brown, pinched, and bent over, never to recover. What happened?!!?

Seedling killed by damping off disease (INAKAvillage211) CC BY-SA 3.0

Causes of seedling loss

There are many causes of seed and seedling loss. To prevent losses, you need to identify the culprit:

• Cutworms emerge from the soil at night and sever seedling stems. They often hide near missing seedlings in the top inch or two of soil.
• Earwigs also come out at night and may chew leaves and stems or take the entire plant.
• Slugs and snails chew irregular holes in leaves or remove them entirely. Look for the tell-tale trail of slime.
• Flea beetles are small, shiny jumping bugs that chew dozens of holes in leaves or eat the whole thing.
• Root maggots leave tunnels in older plants and can destroy seedlings. Look for brown pupal cases.

If none of these pests are killing the seedlings, it may be damping off disease. Damping off is a disease of fungi and fungi-like organisms that clog the arteries of seedlings. Damping off disease can also attack seeds and roots.

Seeds and seedlings are very susceptible to damping off. The fungal spores can survive in the soil for a very long time. As the spores enter, they migrate to the water-carrying xylem and spread, reproducing at a mind-boggling rate, clogging the xylem and killing the plant. If the stems of fallen seedlings are discolored and pinched, it is damping off disease.

How to prevent damping off disease
 
Since infected plants and seeds are doomed, prevention is your only option. Fungi and their cousins love the wet ground. Plants need water, too, so there will be times when the ground is wet. You can reduce the likelihood of damping off and other fungal diseases with these garden tips:

• Improve drainage and soil porosity with compost.
• Be sure to use aged, rather than green, compost.
• Plant seeds at the proper depth - read the packet.
• Plant seeds at the correct temperature.
• Do not overwater and allow the soil to dry out between waterings.

Protect seedlings from damping off disease for a richer harvest.