1 hour ago, Tere said:If they are in the kale / Swiss chard / Spring green food group I reckon they could work up to Canada for sure. Certainly worth an experimental bed if you like them
Collards like a really long, hot growing season. That's why I never grew them when I lived in New England. But that was 20 yrs ago and there may be "quick collards" now for all I know.
Here in Florida they grow like weeds but the bugs love them
ETA - nevermind, I was thinking about okra. It's okra that likes a long hot growing season. We plant collards here in the subtopics in early spring and again in the fall