Comments: Chinese cabbage forms dense heads that may be very upright and tall (Michihili types) or round and barrel-shaped (Napa types). The leaves are slightly wrinkled and thinner than the leaves of regular cabbage with wide, crisp midribs. When choosing what type of cabbage to grow, remember that the darker green leaf and the red varieties provide more nutrition than the light green ones.
Seeds: Plant seeds to a depth approximately twice the thickness of the seed; water and tamp soil firmly. Cover pot with a clear plastic container or wrap, and wait for germination. Keep soil moist but not saturated, and keep pot out of direct sunlight to avoid overheating. Uncover at the first sign of sprouts. Thin to approximately one plant per foot for head varieties.
Transplants: Place in hole no deeper than original root ball, and tamp around stem firmly.
Soil: Cabbage (Brassica oleracea, Capitata Group) grows well in a wide variety of soils, but it prefers a well-drained sandy loam with high organic matter content. Soil pH should be 5.8 to 6.5.
Insects: Several worms (imported cabbageworm, cabbage looper, diamondback moth caterpillar), harlequin bugs, cabbage maggots, aphids and flea beetles are the major insect problems. Solutions: Pick off and destroy larger worms, and spray the plant with biologically friendly non-detergent soap mixed with water (1T per gallon water) for smaller insects.
Diseases: Black rot, wire stem, damping-off, downy mildew, Alternaria leaf spot and watery soft rot are the major diseases. Cabbage is more susceptible to wire stem and downy mildew than is Chinese cabbage. Chinese cabbage is more susceptible to Alternaria. Black rot causes the most serious damage and appears as V-shaped lesions down the leaves before spreading into the water-conducting system of the plant. This disease is caused by a bacterium that is seed-borne or that can be transmitted by transplants. Warm, moist weather favors the disease. Solutions: Compost tea contains organisms that attack fungal diseases and should be used as a supplement and treatment whenever possible. Otherwise, several commercially available fungicides (short-acting so as not to remain viable on the plant after harvest) are available online and at your local home and garden center. There is no control for black rot once it is established in a planting. Prevent the disease by purchasing transplants that are certified to be disease-free, or plant western-grown chemically treated seed.