20-25 days for baby leaf, 40-50 days to maturity. Brassica rapa var. japonica. Red Mizuna Mustard Seeds. Non-GMO, cool-season, annual, hybrid. This small broad leaf mustard has a mild pungency and good red leaf and vein color that intensifies in cold weather. Its leaves are similar to green mizuna but with less deeply cut margins. Red Mizuna is a vigorous salad green that is well adapted for baby leaf production in containers or open fields. Approx. 11,100 seeds / oz.