Napa Cabbage

Napa cabbage is a cool-weather vegetable in the mustard family, grown as an annual or biennial. It forms a dense, barrel-shaped head with pale, thin, tender leaves, and it grows about 1 to 2 feet (30 to 61 cm) tall in the garden. Gardeners also know it as Chinese cabbage, Peking cabbage or celery cabbage. It has a sweeter, milder flavor than regular cabbage, and its crisp leaves can be eaten raw in salads or cooked.

When to sow. Sowing in July works well for a fall crop. Late summer and fall sowings are preferred over spring sowings.

How to sow. Sow the seed about ¼ to ½ inch (0.6 to 1.3 cm) deep, in rows about 2 feet (60 cm) apart. Sow thinly, then thin the plants when they are 1 to 2 inches (2.5 to 5 cm) tall. Leave Napa types 18 inches (46 cm) apart in the row.

Full sun. Give it full sun, with at least 6 hours of direct light a day. Plant in fertile, well-drained garden soil that stays moist.

Spring and transplants. Spring sowings can bolt early if seedlings meet frost or a long stretch of cold nights. A seed company sows in cell trays about ¼ inch (6 mm) deep, keeps soil above 75 °F (24 °C) until germination, and transplants 3 to 5 weeks later around the last frost date.

Watering. Water so the soil is moist at least 6 inches (15 cm) deep, and keep the moisture steady. Mulch helps keep water in the soil and reduces weeds.

Soil and feeding. Get a soil test before planting and fertilize according to the recommendations.

Insects. Aphids, whiteflies, flea beetles, cabbage loopers, cutworms, beet armyworms, slugs and snails can all cause trouble. Cabbageworms, harlequin bugs and cabbage maggots are also common pests. Floating row covers from the day of planting help control flea beetles and cabbage root maggots.

Diseases. Watch for club root, white rust, leaf spot, damping off and bacterial soft rot. Black rot causes the most serious damage and has no cure once it is in a planting, so buy certified disease-free transplants or chemically treated seed. Chinese cabbage is more prone to Alternaria leaf spot than regular cabbage. Long crop rotations with non-brassica crops and strict sanitation also help.

Harvest when the heads feel firm and dense; if they feel loose, they need more time. Cut them when very firm. Harvest promptly once mature, because quality drops quickly. If a flower stalk appears, called bolting, leaf growth stops and the leaves turn bitter. The leaves can be eaten raw or cooked.

Trim the heads and wrap them in newspaper, then keep them in a near-freezing, humid cooler or a root cellar for about 1 to 2 months.