70 to 80 days to maturity. Brassica rapa var pekinensis 'Mansu'. Mansu Chinese Cabbage Hybrid Seeds. Annual Hybrid. This is a Korean loose-head type Chinese cabbage with bolting tolerance and has wide growing adaptability. An excellent choice for Korean kimchee recipes, salads, and soups. You can also use it as a substitute for Green Seoul. It is suitable for spring and fall sowing, and in mild temperature regions, summer sowing is possible. ~ 7,600 seeds per oz.