Do collards not make it thru the summer?
I had a collards relative, Portuguese kale, last year. We slowly turned those plants into what looked like little palm trees

. The curly kale also ends up looking like that. Cut-&-come-again continues right thru the growing season.
These are all non-heading cabbages and I was pleased that I tried the Portuguese kale. It performed about the way
I'd hoped the collards would when I "tried" to grow them. Then, I forgot to order 2013 seed . . . I will look carefully at the seed racks the next time I visit the garden center. They may have put it with the herbs or "Asian greens" because I didn't see it with the kale seed.
Guy Lon (also spelled Kailaan) or Chinese kale really is in that same cabbage/kale/collards family. It has and it hasn't done well for me late. One thing that you have to be willing to do with quite a few Asian greens is eat the flowering shoots. You can treat them as broccoli. This is true also with bok choy - except bok choy is in the turnip family. It is a matter of timing and, since these things can be eaten raw, you can test your preferences in the garden

.
Some of my greens growing migrates into what I call "the shady corner" during the summer. It is actually a separate garden, a triangle, about 30 yards from the little veggie garden. Beginning about 10:30, the shade from evergreens begin to move across that ground. It is pretty much in shadow from there on out. It does fairly well.
Steve