50 days. Here is an old Japanese variety that is superbly adapted to cool weather. An excellent loose-leaf cabbage, the signature savoyed leaves are tender and sweet, perfect raw in salads, or try the leaves stir fried. They retain their nutrients and beautiful chartreuse color even when cooked. Chirimen Hakusai tops the list for cool-season veggies with excellent cold hardiness and the ability to be harvested multiple times. Plants reach a foot in height at maturity.