Chinese Cabbage, Napa 'Wong Bok'

'Wong Bok' is a tender, sweet tasting, hearted-type of Chinese cabbage. Barrel-shaped, with crisp, pale green, tightly-wrapped leaves with a white mid-rib and a dense heart. It forms a stout head to about 25cm (10in) high. Each head typically weighs around 2kg.
The outer leaves curve inward and are dark green to pale green. The interior leaves and heart is yellow to cream coloured. It is the best storing of Chinese cabbages and can be kept several weeks when refrigerated.

The flavour of Chinese cabbages is more subtle and pleasant than our familiar European head cabbage. The water content is higher, they are crisper and more refreshing and also less fibrous. A freshly harvested specimen will often be a little more akin to a romaine lettuce than to our familiar cabbages. The crunchy, pale coloured hearts are delicious eaten raw like lettuce.
Napa Chinese cabbage can be steamed whole, finely cut into slices for a salad, or cut coarsely for a stir-fry. Cooked leaves and stalks add flavour to soups, stews, pasta dishes, and stir-fries.

The world of Asian vegetables is vast and varied, and many are very easily grown at home, and for the little amount of effort expended, it is the greens that give the best return.
Growing this fast growing cabbage, from seed is simplicity itself. Plant the seeds 12 inches apart then simply stand back. Once the secondary leaves appear you are a mere 30 days away from mealtime. This vegetable growing season promises to be very rewarding.

Position:
Grow Chinese cabbage in full sun in cool regions and in partial shade in warm regions. Plant in well-worked, well-drained but moisture retentive soil rich in organic matter. Add aged compost to planting beds before planting and side dress crops with compost again at midseason.

Timing:
Chinese cabbage is a hardy biennial grown as an annual. It is a cool-weather vegetable that will bolt and go to seed quickly in warm weather and long days. Suitable for both spring and autumn sowing, the ideal growing temperatures are from 7 to 24°C (45 to 75°F).
Plants require from 50 to 85 days to maturity and must come to harvest in the cool temperatures and shorter days of spring before temperatures rise above 24°C (75°F) or in autumn before temperatures drop below 7°C (45°F).
Sow seeds directly in the garden as early as 4 to 6 weeks before the last average frost date in spring. Space your plantings with consideration for your needs or you may get swamped. Monthly sowings of half a dozen plants will look after the needs of most families. Phasing the sowing will extend the cropping period.

Sowing: Can be grown all year
Chinese cabbage does not transplant well. Seeds are best sown directly in the garden as seedlings transplanted into the garden may be shocked into bolting to seed. They can be started early indoors, but should be started in biodegradable peat or paper pots which are easily set directly into the garden.
Sow seeds direct into finely raked, moist, weed free soil. Make a drill 12mm (½in) deep and lightly water. Station sow 2 to 3 seeds intervals in rows 30cm apart. Space plants 30cm (12in) apart for upright varieties and 40 to 60cm (16 to 24in) apart for the larger heading types. Seeds germinate in 6 to 10 days at 13 to 24°C (55 to 70°F). Thin out weakest seedlings to leave one per station.

Cultivation:
The plants are shallow rooting so will need watering little and often. Keep the soil evenly moist so that plants grow fast and stay tender. Slow growth can result in plants going to seed. Keep plants cool when the weather warms and shade if necessary do not let plants sit in direct sun for more than eight hours each day.
The heads of looseleaf varieties may need tying lightly with raffia in August to keep the leaves together. Protect seedlings from birds. Added protection from slugs and cabbage white butterfly may be required.

Container growing:
Chinese cabbage can be grown in containers at least 20cm (8in) across. Plants are sensitive to heat so move them into shade when the weather warms.

Companion plants:
Good Companions: Cabbage, Cauliflower, Brussels Sprouts.
Bad Companions: Tomatoes, Peppers, Okra and Potatoes.

Harvesting: 8 to 10 weeks
Cut whole heads at soil level when they are compact and firm and before seed stalks form usually 50 to 80 days after sowing. Complete the harvest before the arrival of freezing weather. If the first autumn frost arrives before heads form, harvest the plants for greens. Napa cabbages can be stored for weeks and even months in the vegetable compartment if refrigerated in an upright position, they can be blanched and frozen for 3 to 4 months.

Origin:
The Chinese people have been consuming these cruciferous vegetables for thousands of years and cultivating many of these cabbage varieties since the fifth century. Until relatively recently we in the west have had to abide by our more coarse and stronger tasting, common cabbage. Chinese cabbage, which has a more delicate flavour and texture, wasn’t introduced to Europe until the 18th century.
The Chinese cabbage as it is known today is very similar to a variant cultivated in Zhejiang around the 14th century.
Chinese leaves were re-introduced to Europe again in the 1970s by Israeli farmers and came into commercial cultivation in California’s Napa Valley at about the same time. Known for many years under the generic names Chinese cabbage, Chinese leaves, and celery cabbage, they are now beginning to appear under their more specific varietal names.

Nomenclature:
Brassica rapa, subspecies Pekinensis are of the same species as the common turnip. Pekinensis cabbages have broad green leaves with white petioles, tightly wrapped in a cylindrical formation.
As the group name indicates, this is particularly popular in northern China around Beijing (formerly Peking). The binomial name Brassica campestris is also used.
The term Chinese cabbage refers to the more than 35 varieties of cabbage from the Brassicaceae, the Cruciferae botanical family. Common names include: Chinese cabbage, Mandarin Cabbage, White cabbage, Flowering cabbage, Celery cabbage, Pak choy, Napa cabbage.
Wong Bok is also known as Napa cabbage. It is widely believed to be named after the Napa Valley in California where it was first commercially planted in the United States, it is the most popular of Chinese leaves in the US. However the name 'Napa cabbage' may also be from 'nappa', the Japanese word for the cabbage.

Chinese Cabbage Varieties:
There are three general types of Chinese leaves cabbages in the Pekinensis group: the 'tall cylindrical', the 'hearted’ (or barrel-shaped) and the 'loose-headed'. They are known more specifically by their varietal or type names such as Michihili, Wong bok (or Napa cabbage), and Pe-tsai.

• The tall cylindrical type has long, upright leaves that form a tapering head. These varieties are generally referred to as Michihili, occasionally abbreviated to 'chichi', the name of one popular tall cylindrical variety.
• The hearted or barrel-shaped types of Chinese leaves form a compact head with tightly wrapped leaves around a dense heart. These are commonly referred to as Wong bok or Napa cabbage.
• The loose- or open-headed type of Chinese leaves has a lax demeanour with outwardly floppy textured leaves. The best known of this type is called Pei Tsai.