What a difference a week makes. I started hardening off my onions and lettuce on the 15th. They have spent a lot of time outside under some nice sunny skies. Before they were floppy and I had to cut them off to 4" when they got too high. Currently they are 8" tall and holding themselves high and proud. I no longer have to snip them for any reason. During the day they are under plastic if the temperatures are less than 50°F. If it is warmer, then they get removed from their tunnel. They have spent several of the warmer nights outside, but not last night. It was cold. By noon it ought to be about 28°F outside. I'll probably put them back in their tunnel then for the afternoon. Until then they have to sit on my kitchen windowsill.
The lettuce has shown great improvement too. It was small and very light green when it started going outside a week ago. Now it has grown substantially and it is picking up its nice red hue. There are three different kinds of lettuce in there, but they are all red.
On March 15th, I had seeded a whole bunch of new plants, cool weather crops and my peppers. They have mostly come up. The exceptions are two of the five chard (I only put one seed in each cell for those unlike the others that have two in each) and one broccoli cell. All the rest have come up well. Most of the cool weather crops were up in 3-4 days and the peppers (on a heat mat) in 5-6 days. After the peppers germinated I moved them into the same flat as the other crops to share the light. I think they will grow fine without extra heat. I've found that chili peppers seem to do OK without extra heat once they are up.
As you can see by the photo, the seedlings are horribly leggy. They are not getting enough light. The LED lights don't seem to be doing the job, which is sad since I love the idea of them. They were fine for the onions that really never get leggy. They just get floppy and you can cut their tops off to compensate. The only other one I had seeded before was the lettuce and lettuce has a high tolerance for shade. It wasn't leggy then and the new seedlings coming up still aren't. I think the LEDs need to be twice as close together (they are 3/4" apart in all directions). Next year it is going to be back to fluorescent lights I think. I might have to break down and get one for this year. Some of those seedlings are 2" tall already and still only have their seed leaves. I might try natural light for a while. I have sunny windows that face southeast and southwest and with a reflector it might just be enough. Right now despite being in a sunny windowsill they don't see natural light. The LEDs are so close to them they block all the natural light.