William Shakespeare wrote in “Much Ado About Nothing” of a character’s “February face, so full of frost, of storm and cloudiness.” Translating the quote into gardenspeak, it’s the look a gardener pulls upon discovering a tray of tender young seedlings smothered in their soil beds.
Indoor seed starting season has begun in earnest. While gardens are still half-frozen and mucky, some gardeners can’t wait to get their hands dirty sowing seeds for spring gardens in trays, peat pots, plastic milk jugs, egg cartons and anything else that holds soil and seeds.
It’s exciting to see tiny seedlings pop out of the soil, full of promise. The next day, they’re withered, brown, watery and dead. What happened?
“Damping off” is the common term for this villainy of Shakespearean proportions — a group of fungal diseases, actually, including root rots and molds like Rhizoctonia, Fusarium and Pythium — visited upon pre-emergent and emerging seedlings. These infant seeds can’t withstand the invasion of these cruel pathogens.
Damping off can seem sudden or happen more slowly, say extension service horticulturists. Stems may look mushy, thin or constricted. Cotyledons — the first leaves on seedlings — may look sickly and discolored; true leaves may wilt and be discolored. Below the soil line, roots may rot or show ugly sunken blotches. White cobweb-like growth may appear.
There is no cure. Diseases can be transmitted on dirty hands and tools, in reused potting soil, carried by fungus gnats or through common water sources like hoses and sprinklers.
Too-cool, low-light conditions can cause damping off, along with over fertilizing and cool soil temperatures. Once it starts, it easily spreads to other seedling trays, so quickly remove infected trays.
You may be able to purchase vegetable and ornamental seeds pre-treated with fungicide to protect against damping off the seed. If you want to treat seeds yourself, place a very small amount of powder fungicide directly into the seed packet or in a jar. Shake the seeds to coat, then plant.
If seed is from last year, test germinate several seeds to make sure they are viable.
Here are eight recommendations from experts:
1. Sterilize pots, trays and other containers for 30 minutes in a solution of 10-percent household bleach.
2. Always use new potting soil recommended for seed starting. Don’t reuse old mix, compost or garden soil. Plant seeds at the proper depth (read seed packet label).
3. Clean tools after every use and store in clean location.
4. Keep soil temperature at 70 to 75 F by using a heating pad under trays.
5. Keep potting mix moist but not wet, and make sure containers have good drainage and don’t sit in water.
6. Use clean, warm water (68 to 77 F) on young seedlings and water from the bottom, if possible. Cool or cold water can increase chances of damping off. Don’t overwater.
7. Don’t fertilizing until several true leaves develop. Apply water soluble fertilizer at ¼ strength; if potting mix contains fertilizer, no additional feeding is needed.
8. Use grow lights or soft white fluorescent lights for 12 to 16 hours a day. Window light isn’t enough.