It takes a couple of months to grow cabbage, but some varieties are worth the wait. Napa cabbage, one of two Brassica rapa subspecies sometimes referred to as Chinese cabbage, is a large, puckered, tight-headed, fresh green with a flavor that is sweeter and milder than traditional cabbage. It is no more difficult to grow than traditional round-headed cabbage and is very versatile in the kitchen.
The large, oblong leaves are crinkled and very tightly wrapped into an upright-growing head. The stalks are almost white and the leaves are a very pale green. Napa cabbage flowers exhibit the familiar four crossed yellow petals found in other members of the cruciferous family.
Napa cabbage is sometimes planted in the early spring for mid-summer harvest, with seeds often started indoors several weeks before last frost. In most regions, it is more common to plant napa cabbage in mid-summer for fall harvest. Whenever it is planted, the heads will be ready to harvest in 70 to 90 days after seedlings sprout.
Brassica rapa (Pekininsis group)
|Common Names||Chinese cabbage, Napa cabbage, Peking cabbage, Celery cabbage|
|Plant Type||Biennial vegetable, normally harvested in first season|
|Mature Size||Full-size heads grow about 20 inches tall and fill out to 5 or more inches in circumference.|
|Sun Exposure||Full sun to part shade|
|Soil Type||Rich well-amended soil|
|Soil pH||6.5 to 7.0 (neutral)|
|Hardiness Zones||4 to 7 (USDA); normally grown and harvested as an annual|
|Native Area||Near Beijing, China|
How to Grow Napa Cabbage
Napa cabbages do not need a lot of tending, though they do need regular water, especially during hot spells. Drought will cause bolting. If you amended your soil, you should not need supplemental fertilizer. However, if your plants look like they need a boost, use a fertilizer high in nitrogen, such as fish emulsion or soy meal.
Napa cabbage matures in 10 to 13 weeks. Early spring sowings can be hit by frost or cold nighttime temperatures, which can signal that it is time to start setting seed and cause the plants to bolt. If you get past that hurdle, the warming temperatures will also tell the plants to stop growing and focus on going to seed. Although it is not impossible to grow napa cabbage in spring and early summer, planting in mid-summer allows the plants to mature as the days cool in the fall.
If you choose to plant in the spring, either direct sow or start seed indoors about four to six weeks before your last frost date. Hold off spring sowing outdoors until after your last frost date or be prepared with some type of row covers.
Plant seed 1/4 to 1/2 inch deep, spaced 6 inches apart. Thin and eat the thinned plants when they are a couple of inches tall. If you are growing full-sized plants, thin to a 12- to 18-inch spacing to give the heads plenty of room to develop.
Napa cabbage can grow in full sun or part shade. It must, however, get at least four to five hours of sun each day and plenty of water.
Since napa cabbage has a relatively long growing season, you will want to start with rich, well-amended soil. Start by digging in several inches of organic matter, such as compost or well-rotted manure. Soil pH is not a big concern but aim for something in the range of 6.5 to 7.0.
Napa cabbage should be watered regularly to encourage growth and reduce the likelihood of the plant going to seed too early. Provide about 1 inch of water per week, either from rain or from direct irrigation.
Temperature and Humidity
Napa cabbage can handle both warm and cool weather. In milder climates, it will grow year-round.
While Napa cabbage does not absolutely require fertilization, it benefits from a topdressing of compost. Alternatively, once a head begins to form, apply fish emulsion or a 20-20-20 soluble blend.
Varieties of Napa Cabbage
- 'Blues F1': This is an early-season variety with bluish-green leaves. It is disease- and bolt-resistant and is a good choice to try in the spring. It matures in 57 days.
- 'Chinese Express: This is a glossy leaved, late-season variety, also with good bolt resistance. It matures in 90 days.
- 'Monument': This mid-season variety has tall, narrow heads. It resists bolting and matures in 80 days.
Napa Cabbage vs. Bok Choy
Napa cabbage is very similar to bok choy, which is merely a different sub-variety (chenensis group) of the same species. In fact, both are often called Chinese cabbage, and both are regarded as subspecies of the turnip. Bok choy bears a closer resemblance to Swiss chard, with darker leaves and a different texture. Napa cabbage is said to have a milder taste than boy choy, which is similar to ordinary head cabbage in flavor.
Common Pests/ Diseases
Napa cabbage does not share the quick growing advantage of many other Asian greens. This makes it a target for the usual line-up of brassica pests and diseases, including clubroot, cabbage yellows, black rot, and blackleg. Do not plant napa cabbage in a spot that had Brassicas growing in it previously, since these common pathogens may persist in the soil.
In addition to cabbage worms, cabbage loopers, and flea beetles, be on the lookout for slugs and cabbage root maggots. Whiteflies and aphids are less of a problem.
Harvesting Napa Cabbage
Napa cabbage is ready to harvest when the heads feel firm. Test for maturity by squeezing the heads. A mature head that is ready to be picked will feel dense, with little give.
Napa cabbage is a very versatile vegetable in the kitchen. It can be used in recipes calling for either regular cabbage or bok choy. Individual leaves are often used as wrappers, for steaming or blanching. It is great for a mild, Asian inspired coleslaw and it also makes a mean Korean pickled Kimchi. Grilling it brings out its natural sweetness.