Very few people in the US grow Chinese cabbage, but they are one of the oldest vegetables grown in China. Because they have few insect pests, these cabbages are actually easier to grow than tomatoes.
Chinese cabbages are loose leaf cabbages and include ornamental cabbage and bok choy. Ornamental cabbages can be grown in flower beds as edible ornamentals and thrive in cool weather. Choose early, mid and late season types of Chinese cabbage in red, green or purple colors for an extended, colorful harvest. They are also well suited for greenhouses and can be grown year round in that environment.
Although Chinese cabbage can be purchased as transplants from a nursery, the plants are easy to grow from seed. Plan the planting time so the plants can be set out up to four weeks before the last expected frost. Plant the seeds about four weeks before that which means the seeds should be planted approximately eight weeks before the last frost in the spring. Sow seeds indoors a quarter inch deep and two inches apart or plant two seeds per biodegradable garden pot. Place them in a sunny location with temperatures between 60 and 70 degrees F. Keep the soil moist by covering the planting container with breathable plastic. Remove the plastic when the plants germinate.
Plant the seedlings outdoors when daytime temperatures reach 50 degrees F and the seedlings have three leaves. Plant the cabbages slightly deeper than they grew in the growing flats. Make the planting holes large enough to accommodate the roots, sprinkle the planting hole with kelp powder and water well, the plant the cabbage and water them thoroughly again.
Give Chinese cabbage plenty of room to grow as they will develop huge heads, allowing up to two feet between cabbage heads. If your garden space is limited, plant other quick growing vegetables around the cabbage like lettuce, green onions, spinach, radishes and turnips that can be pulled out as the Chinese cabbages grow and begin needing the space.
Start your late crop in midsummer about ten weeks before the first average frost date by sowing seeds directly into the garden. Space them further apart than the spring planting and also plant them in a location where they are shaded from the afternoon sun by a taller crop like trellised tomatoes.
Side-dress the plants with compost after they have been in the garden three weeks and then place mulch over the compost. Water them around the roots and try to avoid getting the leaves wet to help prevent disease. Reduce the amount of watering as the cabbage matures.
Chinese cabbages have fewer problems with disease or pests than regular cabbages. If cutworms become a problem, try placing crushed egg shells on the soil around cabbages. If you notice that something has been eating the Chinese cabbages, sprinkle the plants with diatomaceous earth, wood ashes, or hot pepper and soapy water spray. To help avoid plant diseases, work compost into the soil every year and avoid planting Chinese cabbages where other members of the Brassicaceae family were grown during the previous season.
Chinese cabbage grows well with other Cole crops like Brussels sprouts or cauliflower. It should not be grown near corn because the corn worms will infest it.
Keep Chinese cabbages in the ground until you are ready to use them if possible. Freshly cut Chinese cabbage is more nutritious than cabbage that has been stored. Use a sharp knife to cut the heads when they are firm and cut the heads at ground level. Remove the roots and toss them in the compost pile. Refrigerate the cabbages until they are used. Cabbages will keep in the refrigerator for two weeks.