I think if you experiment with timing you can.I wonder if I can grow collards in the green house? It's not heated. But maybe it also doesn't have the bugs that have eaten EVERY SINGLE COLLARD I have ever tried to grow!
They are very heat and cold hardy. Just know that a larger plant is more cold hardy then a seedling. As days get shorter growth slows also. I set seed in mid July indoors underlights. About 4 week old plants move to greenhouse then to morning sun to get ready for the ground. It is hard to keep seed moist and away from bugs in July/Aug. This method helps me tremendously. I have a big harvest Oct and Nov. to freeze for us and share with a few family members. I like to have 25-30 plants. Only a few plants would occasionally feed 2 just fine.
Many old timer's (gee, I think I'm one now. lol) will set out small plants in March when they plant potatoes. They grow collards all summer, fall and winter. Never cutting whole plants.
During warm weather Brassicas will draw every bug in the county! This is why I just grow during the cooler months. During summer I grow other things.
Maybe this will help you decide how it works with your climate. I am zone 8a they say but I still make gardening decisions like zone 7.
 
	 
 
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
 
		 
		
 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		