40-50 days to maturity. Brassica oleracea var alboglabra ‘Big Stem’. Big Stem Chinese Broccoli Seeds. Non-GMO; hybrid; cool-season annual. Closely related to European cabbage, Chinese broccoli was introduced to China in ancient times and quickly accepted into the local cuisine. The leaves are big and dark green with thick stems. Suitable for growing during multiple different times of the year. This open-pollinated variety has deep green color, good flavor, and large stalks that are crisp and excellent for slicing. Stems are tolerant to cold and slow to bolt. Approximately 9,000 seeds per oz.