Mustard greens can be grown in the spring, summer, and fall, though they prefer an air temperature range of 60 - 75° . Direct sow seeds outdoors 4/15 - 8/30. For baby greens, broadcast sow seeds ½” deep, 60 seeds per square foot. For mature leaves, sow seeds 1” apart in rows 18” apart. Days to germination: 4 - 10. Sow every 3 weeks for continuous harvest, or let them re-seed themselves to have low maintenance self-sowing, edible “weeds”. Keep well watered during hot weather. It can grow in part shade. Tolerant of light frosts.
Baby greens: cut entire plant when 3 - 6” tall for cut-and-come-again baby greens (cut plant with scissors 1 - 2" above soil level so you don’t damage the growing crown.) Return for several harvests. Harvest mature leaves individually as desired. Eventually the plants will begin to “bolt” (flower) and make seed. (See Seed Saving Instructions.)
Brassica juncea is insect pollinated and will cross-pollinate with other Brassica juncea mustards (which are not that common). Isolation distance: ½ mile. Minimum population size: 10 plants. Collect seeds from the best plants once pods have turned from green to tan but before seeds have been released. Clean seed as a dry-seeded crop.