Collards are a member of the brassica/cabbage family, and cultivation is similar. Best grown as a fall crop, time your collards to harvest around first frost. In fact, a light frost will improve the flavor. Direct sow or start indoors in cooler soil, about 60-75F. Plant 1/2 in deep, 1 in apart, in rows 2 ft apart and thin to 2 ft apart once established (try using the thinnings as fresh baby greens for your favorite salad).