These are photos of my seedlings over the past 2 weeks. The tray at the top was started Jan 28. Mostly lettuce, endive and onions. I put them out in the cold frame around March 1. Some of the seedlings frosted because I didn't realize the plastic panels of the cold frame ripped in the wind that week.
The bottom seedlings were started Feb 26. Broccoli, celery, frissee, dill, radicchio and more onions. They are ready to go out to the cold frame soon.