10-15 days microgreens; 20-30 days baby leaf; 45 days full maturity. Brassica rapa var chinensis. Da Hong Summer Hybrid Pak Choi Chinese Cabbage Seeds. Non-GMO, cool-season annual, hybrid. Da Hong Summer is slightly denser than other purple pak choi, forming a more developed head, and firmer petioles. Its heat tolerance is higher than many other pak choi, and it can also weather greater temperature fluctuations between day and night without bolting. ~ 9,500 seeds per oz.