Hi...I live in Mississippi so summers are hot. I planted 1 row of collards & 1 row of mustard greens in March...about 15' rows. I fed my tortoises & dragons on them all summer. The greens did die out in the heat the end of Aug. In Oct I planted 2 15" rows of collards & 1 row of mustard greens, as well as muselix (sp?) which is like spring mix. I planted the rows about 18" apart. They are still producing without needing to cover them. I only bought 3 bags of greens from the store this winter, when I was expecting days of rain. I would melt if I tried to pick greens in the rain for all my dragons & tortoises!!
I also planted carrots in Oct, but the dragons don't seem to like carrot tops. A couple of the tortoises like them. I use the carrots for feeding crickets & superworms. I also planted baby pumpkins & butternut, summer, & zucchini squashes in March. I cut & steamed the squashes, as well as pumpkin and froze it for this winter. They have enjoyed it and I still have enough to last til the next crop is ready.
I lived in NY state for a while. Most people have basements which stay cool but usually isn't freezing so veggies can be stored there for quite a while.
And by feeding the pumpkin, all 10 fecals I did last week on my dragons were negative for parasites. I am pretty sure the others are negative as well.
Since we can't use fertilizers, I bought lots of bagged cow manure from Walmart...about $1 for a 40lb bag. Home Depot also carries it for a few pennies more.
Good luck
Patsy