Brussels Sprouts are a member of the Brassica (Cabbage) family. They should be planted outdoors in mid to late May about 1/4 inch deep, to be transplanted into place about 5-6 weeks later, spaced 2 feet apart in rows 3 feet apart. Brussels Sprouts are best timed to harvest after fall frosts have begun, as the flavor will improve with each frost. Harvest from the bottom up often until winter sets in. Typical of the brassicas, they need a fertile soil and consistent moisture to perform best.