my chinese cabbage has done the same, and this is how i find you have the same problem,have found this,
Chinese cabbage which includes pak choy, bok choy, Michihli, and celery cabbage is a cool-weather vegetable. Sow Chinese cabbage directly in the garden as early as 4 to 6 weeks before the last average frost date in spring. Chinese cabbage must come to harvest in the cool temperatures and shorter days of spring or autumn before temperatures rise above 75°F. Plants require from 50 to 85 days to come to harvest depending upon the variety.
- 14 Jul, 2011