Trouble with Seedlings : Damping Off

tomato seedling riddled with damping off

Scott and I aren’t experts at seedling fatality diagnostics, but we’re pretty sure that for the last two years in a row at least one of our tomato seedlings has succumbed to ‘damping off.’ Damping off or seedling rot is caused by fungi that live in the soil. When you keep the soil continuously damp, give it some high humidity and maybe some cloudy days it sets that fungi in action and ready to destroy your fragile little seedling stems.

healthy seedling

How Do You Notice Damping Off?
We first notice it when the base of the 1″ stems get thin and white, the next day they fall over and die. Sometimes the damping off will affect your seedlings before they even sprout.

How can You Prevent it?
You can prevent Damping Off by sterilizing everything before you plant your seeds. If you make your own seed soil mix you can sterlize your seed soil in the oven with this tutorial. Make sure to wash your planting flats thoroughly too. When seedlings are crowded together that also will activate the fungi, so try to only plant one seed per planting cell.

What to Do When You Spot Damping Off.
Believe it or not, there is a slim chance that you can rescue your poor seedlings from damping off. When you first spot it stop watering right around the base of the plant. Give the seedlings as much light and air as you can. However we’ve had our seedlings our in bright sunlight with low humidity and they always die on us. My recommendation would be to start new seeds immediately when you spot it because chances are slim that you’ll save your new growth.

This year due to all the house renovations we’ve undertaken and our battle with damping off, we’re going to be buying most of our tomatoes and peppers. That’s just fine, it feels good to take a year off from nuturing seedlings in pots.

Have you had any seedling fatalities this year so far?


Filed under Seeds, Soil, Sprouting

11 responses to “Trouble with Seedlings : Damping Off

  1. I’ve been lucky so far this year. Leggy seedlings I’ve had, but not any falling over due to rot. I’ve been spraying with chamomile tea this year. That may be the reason. Or it might be randomness.

  2. Oh I too have faced the damping off! Like you, this year I am not growing any seedlings at home, but I do have some fostering at a friend’s house.

  3. Rasa

    Oh! I’m growing seeds right now, for the very first time, using a kit that came with sterile pods of soil.

    A few of the seedlings have emerged so far (but not all), but I just noticed this morning that at least one (and maybe a couple others) have a fine white fuzz growing on top of the damp soil. Looked like a fungus to me.

    I had never heard of this phenomenon of “damping off” before, but it totally makes sense. I’m heading downstairs to take off the cover and put the tray into the sunlight immediately. I hope I caught this early enough!

  4. I’m just getting back to seed-starting this year, but I always used to prevent damping off by covering the seeds with vermiculite. Never sterilized the soil because I prefer live soil. Vermiculite is a mined product and therefore a less sustainable choice, but I liked it. A fan can help too.

  5. Funny that I should read this (while searching for picture proof of what a grown toonas makino pumpkin looks like) because I’m reminded that I need to start over with the eggplant seedlings! So sad to see them rot off like that after having waited so patiently for them to germinate. Love your blog!

  6. I have tried the chamaomile tea route and also (When too lazy to make tea) added two drops of tea tree oil to the watering can..and so far no dampening off this spring.

  7. TechChik

    I’m using the chamomile tea method too, and it’s worked beautifully for me. The first time I watered my pre-germinated seedlings I used the tea, and then with water as needed afterwards. I haven’t had a single case of damping off yet. *knock wood!* Just to be extra safe, I may water with tea again in a week or so.

    I’ve also heard that cinnamon powder sprinkled on the soil surface works well, but I haven’t tried it.

  8. Pingback: Help!!! Seedlings all dying. - Marijuana Growing

  9. Gary

    I just took the Tomato Germination class from Love Apple Farms here in Santa Cruz.
    The solution for this problem, is to use a fan if you keep the seedlings inside.

  10. some of my seedlings are starting to damp off again… what do i do to rescue it.. so far its moist… thanks! 😀

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