A good tip for growing napa cabbage, also known as Chinese cabbage, is to make sure to plant seeds when the temperature is ideal. It is also important to ensure the soil is properly prepared before planting. Since napa cabbage grows best in neutral to slightly acidic, nitrogen-rich soil that is heavier but drains well, fertilizer or other additives should be added accordingly. Proper planting and watering techniques are also important. It may also be wise to monitor the plants for premature flowering.
Premature flowering, or bolting, is a survival technique for the plant. If conditions are unfavorable for a plant's survival, it will try to produce seeds. Once a plant bolts, most of the plant’s energy goes to producing flowers and then seeds. Should a napa cabbage bolt, a person may end up with tough, bitter leaves. To prevent this, a gardener should ensure that he causes as little stress to the plant as possible.
Napa cabbage is a cool weather plant. Ideally, the plant should be grown in full sun at temperatures of 60-70°F (15.5 to about 21°C). Despite this, a gardener does have a choice when to plant so that he can harvest when he wants to. For harvesting in the summer, napa cabbage should be planted in the spring. If a yield is desired in the fall, seeds should be planted in late summer.
In order to achieve a summer harvest, a person should plant napa cabbage seeds indoors approximately four to five weeks (some gardeners recommend eight to ten weeks) before the last spring frost. It may be best to plant each seed into an individual pot in order to prevent trauma while transplanting young plants. A gardener may also choose to plant the seed in a peat pot which, after removing the bottom, can then be placed directly into the ground outside. It is important that the last frost of the spring season has ended before transplanting as a cold snap can cause the plant to bolt. When planting in the ground, seedlings should be placed about 12 inches (about 30 cm) apart.
For a fall harvest, the napa cabbage seeds can be planted directly outside. The best time to plant may be about three months before the fall frost. Seeds can be planted about four inches (about 10 cm) apart but should be thinned to 12 inches (about 30 cm) apart when the seedlings are about two inches (about five cm) high. The plant should also be kept cool and well watered, allowing the surface soil to dry out a bit between irrigations. It is important to note that if the plant gets too hot or too dry, it could bolt.