Pak choi is a fast growing type of Chinese cabbage. The young crisp stems and leaves are used in salads - picking selectively from several plants allows the plants to grow new leaves to prolong the harvest period - or the plants are left to mature to use the leaves in stir fries and other cooked dishes. If growing for young leaves, the plants should be spaced about 10 centimetres or 4 inches apart, whilst mature plants will need 30 centimetres or 12 inches between them.
Pak choi has a tendency to bolt in hot weather. Breeding innovation has produced F1 varieties that are better suited to hot temperatures, and keeping the soil moist will also help prevent bolting. In hotter regions of the UK, it may be beneficial to find a position that offers the plants partial shade. Pak choi will perform best in rich soils, and as they are fast growing and relatively small in size, they are suitable for growing in containers and raised beds.
Pak choi seed can be planted directly in the soil when the weather starts to warm in the spring, and then in succession through the summer to provide a supply of leaves over many months. Young leaves can be harvested after 5 weeks growth, and the plants will be mature at about 10 weeks. The plants are hardy, and late summer sowings will provide a harvest in autumn and early winter. For an even longer harvest period, early and late sowings can be made in a polytunnel.