When I planted these cabbage in the spring, the label read 'fast growing, green cabbage.' I assumed these were Brassica oleracea or European cabbage so I only have myself (the labeller) to blame when I realized, some time later, that they are Chinese cabbage or Brassica rapa. At any rate, they are still tasty (and green and quick growing and a cabbage). Normally I wouldn't plant these until the fall because of their tendency to bolt before forming large heads. They grew to a descent size before the florets began to show. Besides, mistakes form the basis for 50% of my gardening education. My conclusion, however, remains the same. Growth is better in the fall and clear labelling is a must when seed saving.
Not to worry, there is still lots of long season cabbage growing in the garden that came from well labelled seed.