Culture
Pak choi is a cool season plant that will tolerate light frosts. Seeds should be sown about ¼ inch deep in early spring for a spring and early summer crop or in mid to late summer for a fall crop. Spacing is dependent on the size of the particular variety being grown and on its intended use. Pak choi that is to be harvested in the immature or baby stage may be grown much closer together than pak choi that is to be grown to the mature stage. Harvest pak choi whenever it reaches the desired size by picking individual leaves or cutting the whole head at ground level. If sown during the summer, pak choi will have a tendency to bolt, although that may be lessened by consistent watering and harvesting the plants when young. Pak choi grows quickly making it a good plant for intercropping. Row covers may be useful in preventing insect and frost damage.
Noteworthy Characteristics
There are several names for the Asian vegetables in this group including pak choi, bok choy, Chinese celery cabbage, Chinese white cabbage, mustard cabbage, and choysum. Most are characterized by a loose head of green leaves with white stalks. (Pak or bok translates to white and choi or choy translates to vegetable.) There are many kinds available ranging in size from 3-4 inches tall to 24 inches tall, with leaves from dark green to light green and with stalks from white to pale green.
Genus name comes from the classical Latin name for cabbage.
Specific epithet means relating to turnips.
Problems
Insect pests include flea beetles and caterpillars such as cabbage loopers and cutworms. Slugs and snails may also be a problem. Diseases include club root and rots such as damping off and bacterial soft rot.
Uses
Pak choi is edible as seedlings, small immature heads, large mature heads, and while flowering. The stems are mild and juicy while the leaves have a cabbage-like flavor. It may be eaten raw in salads or braised, steamed, stir-fried, or cooked in soups.