If I had a greenhouse I would be growing lettuce in it as long as possible.
It’s a great jump-start in the spring, and I’ve had lettuce through mid-December in mild years. Spinach is started in there, and lettuces will be following this week.
Not sure why I love lettuce like I do! I mean, I love salads, but I think lettuces are so unique and pretty. On, ‘Diana’s Useful Scale’ it’s right up there with chickens, LOL!
At my other farm, my wood-framed greenhouse was pretty rickety. In fall it got sun all day, since the trees had dropped their leaves. A branch of a Climbing Rose (’New Dawn’) grew up through it, and I had blooms in early winter, one year. Kinda fun. ;)