50-60 Days to maturity. Brassica rapa var Pekinensis 'Blues'. Blues Hybrid Chinese Cabbage Seeds. Annual Hybrid. This early maturity Chinese cabbage (Nappa) has many qualities like being widely adaptable for most North American growing areas, having strong bolting tolerance, and being resistant to viruses, Downy mildew, leaf spot, Alternaria leaf spot, and Bacterial soft rot. Look forward to using its 4.5-pound heads in your favorite cabbage dishes. Approximately 2,800 seeds per oz.