45-50 days to maturity.Brassica rapa var chinensis. Chun Mei Pak Hybrid Choi Chinese Cabbage Seeds. Non-GMO, late maturing cool-season annual, hybrid. Chun Mei hybrid is very slow bolting standard large size shangai pak choi. It stands upright, and its leaves are dark green with broad, long, and shiny green petioles. It has good cold and heat tolerance and has a flexible planting time. Don’t skip on this nutrient-dense leafy vegetable in your garden this year! ~ 9,750 seeds per oz.