Have you ever had your seedlings wilt and fall over suddenly?  They were growing great guns when you checked on them.  A few hours later, they were sprawled over the ground like drunken sailors, never to rise again. You have had an encounter with damping off.

Damping Off

Damping off is an umbrella name for an infection caused by one of three organisms: Pythium species, Phytophthora species, or Rhozoctonia solani. All three are fungi that infect the roots of the baby plant, then spread upwards.  At or just above the soil level, the plant stem pinches in and turns brown, the plant keels over, and your beautiful seedling is no more.

Excessive Soil Moisture

Excessive soil moisture is the culprit.  This occurs in exactly the conditions that are most common around seedlings:  high humidity, lots of plants together, poor ventilation, and compaction of the soil.  Reusing soil trays to start your seeds without bleaching them out first will spread it year to year.  You should also use a pasteurized soil mixture for the same reason.

Just Right Moisture

Finally, be careful of your soil moisture.  You want the soil wet enough that the seeds germinate and grow, but not soggy.  That invites fungal diseases.  Sometimes, the fungi will rot out the seeds, making them appear to have a poor germination rate.  In others, it waits and ambushes the seedlings.  Either way, you end up with nothing to show for your efforts.

Immediate Quarantine

Once the seedlings start wilting, the only thing you can do is isolate that flat of plants from the others and change your watering to reduce the moisture around the seedlings that remain.  The ones that have keeled over are dead.  Throw them away, do not compost them.  No use spreading the infection to your compost heap.  Discard the dirt they were growing in, too, and bleach the growing tray well so the fungus cannot live in it until you use it again.

Water Differently

For the flats of seedlings that have not died yet, you need to reduce the amount you are watering and make sure you do not splash dirt on the leaves of the plant when watering.  You want the soil moist enough to germinate the seed and keep the seedling from wilting, but not squishy.  Squishy soil is a fungal haven.   

Even after you change your watering practices, you will probably lose additional plants.  They were already infected and just hadn’t died yet.  Do not be discouraged.  Just start more seeds in bleached trays using pasteurized soil.  Don’t overwater, and you should be okay.

Want to learn to garden? My first attempt at gardening ended up in failure. The weeds took over and squeezed the vegetables out. I was very frustrated by this waste of good seed, time, and money. So I became a master gardener and spent a lot of time helping other people avoid or overcome problems in their garden. 

In order to help others garden successfully, I have written a book, Vegetable Gardening from the Ground Up, available in an ebook or a paperback from Amazon. It is also in Kindle Unlimited.