I planted my pepper seeds about 4 weeks ago and my tomato seeds 2 weeks ago. The seeds germinated quickly, they look healthy. I have them under fluorescent lights (warm/cool combo) about 16 hours/day. They are still on their heat mat in a covered indoor greenhouse setup in my basement. The seedlings look great, but they have not developed a set of true leaves yet and I think that they should have by now. Suggestions? I was waiting until they developed their first set of leaves before I turned off the heat mat-maybe too warm? Too much light? I need advice-I don't remember having this happen before:(
The heat mat should only be used to help the seeds germinate and the cover is just used to keep that heat in. To prevent possible root rot, leggy growth, damp-off and other fungus issues, the heat mat and plastic cover should be removed at the first sign of germination. At this stage, your seedlings need cool ambient temperatures (60 to 65 deg F is probably ideal), good air circulation, and (as doug has suggested) lots of light.