I put seeds out in the fall because they are a winter crop here in the South. Mine have been eaten and finally pulled 2 or 3 weeks ago. The ones that were not pulled, I kept for the blooms which are 3.5 feet tall.
Plant some seeds in the fall directly in the ground, also, as an experiment.
I also bought the same variety (as my seeds) in a six pack at Walmart in the fall. They matured a lot faster, of course, and were huge and the most unbelievable flavor I ever tasted, for a green.
Think I prefer the 6 pack better than seeds. 6 huge plants provided more greens than we needed. Plus the greens were eaten before the bugs showed up.
Picture of one when it was small.
You might wonder why this one is in one of the flower beds. I really was going after the blooms.