Dead seedlings?

[Cheri Cason]

I have a small greenhouse and have been trying to start my spring plants. I have them in a Jiffy Pot covered growing container, and on a heat mat. The problem is - when the seedlings emerge and they have their tiny top leaves, I took the lid off (it's warm in my greenhouse) and the leaves almost immediately shriveled and died. Looks almost "nipped" just below them. Any ideas? Thanks.

[flowerpower]

Sounds like it could be "damping off". Here's a link with pics of it

http://www.hort.uconn.edu/IPM/greenhs/htms/dampofgh.htm

[Pharmerphil]

if they are "nipped" as you say, at the soil surface, then it is "damp-off"
How quick a transition was this from covered grow tray to the "warm" grenhouse? sometimes a quick change will affect just the plants tops.

[TennOC]

Yup, they're right. Take the lid off as soon as you can see ANY growth above ground. Don't wait for the seed leaves to unfold. That will let the surface dry a bit. When you water, do it by setting the pot or tray in a container of water and let the water seep up from the bottom. Don't let it soak, just a dip. You will feel the pot get heavier, take it out then.

[Cheri Cason]

Nope, not nipped at ground surface. Just below the tiny leaves.. they turn darkened, the leaves fall over.. then that's IT!

[flowerpower]

Cheri, I bet it's happened to all of us. You can try starting plants that can take the cool temps. Start perennial or biennial flower seeds. If it says "chill for X amt of days'', start it. You could try growing lettuce in a pot or planting box.

[Cheri Cason]

Ok, thanks! I'm starting my garden plants, though..

[Cheri Cason]

Have you checked the night time temps in this greenhouse. What you are describing sounds like frost. When I have had a late frost and I had already put my plants in the ground the leaves darkened and then fell off. Seedlings are very susceptible to cold. When you had them covered the heat mat was generating enough heat but when you took it off the air temperature at night killed the seedlings.

I started a group of seedlings to test a new method of seedstarting and have had no problem because I have the plants in the house.

Perhaps it might help if you brought the seedlings inside the house during the night until the evening temps are higher.

LoreD

Thanks, I'll try that!

[TennOC]

Cheri, you're not a real gardener till after you've killed a few plants :)