Mustard greens are "brassicas," related to broccoli and cabbage. Avoid planting them in the same spot two years in a row to prevent soil-borne diseases. Rotate them with non-brassica crops like tomatoes, peppers, or beans.

Mustard greens can be grown in early spring or late summer/early fall. They prefer cooler temperatures and can bolt (go to seed) in hot weather. In temperate climates, sow seeds 4-6 weeks before the last frost date in spring or 8-10 weeks before the first frost date in fall.