Cabbage Seeds - Pak Choi - Jimao Choi - Hybrid. Annual. Brassica rapa Chinensis group. 20-30. Cool-warm season. NonGMO. Open pollinated. This is feather type pak choi. Plants grow fast (20-30 days) and upright. Leaves are green oval-long spoon shape with green petioles. Tolerant to heat. Excellent for baby leaf production. Prepare fertile well-drained soil. Sow seeds in spring after last frost to early summer or late summer/early fall. Keep soil moist. Fertilize as needed. Optimum growing temperatures are in the 60s°F. Exposure to frost or prolonged temperatures below 50°F may result in bolting. Mulch fall crops to avoid premature bolting. Use in stir-fries saute or braise. About 5000 seeds an ounce.