80 Days to maturity. Brassica rapa Pekinensis 'Monument'. Monument Chinese Cabbage Hybrid Seeds. Annual Hybrid. Monument is a well-known Michihili type of Chinese Cabbage that has a sweet flavor and is one of the better cabbages for storage. It does take a bit longer to mature though so be sure to plan ahead. You can expect to see a 4-4.5 pound head form with an upward cylindrical shape. Add this to your unique garden must-haves as an element of vertical interest and sweet addition to your favorite summer ingredients. ~ 9,000 seeds per oz.