Sow from March until August outside or use cover for earlier or later sowings. integrifolia, Brassica juncea subsp. Production time can be as short as four weeks. Speciality leaves are now an established sector of the salads market. Banyan Botanicals Brown Mustard Seed - USDA Organic - Heating Spice That Promotes Healthy Digestion - Brassica juncea. Terms of Service Agreement - 100 grams Brassica Juncea Seeds (Mustard Greens Seeds) USD14.00. A good variety to follow F1 Navona.