Chinese chard (Bok choi)
Note Number: AG0926
Published: June 2000
Updated: June 2012
Chinese Chard, Brassica rapa var. chinensis is a member of the Cruciferae family and also commonly known as Bok Choi, Pak Tsoi and Pak Choi.
Chinese chard is a popular Asian vegetable cabbage that has a number of different types. To simplify the different types of Chinese chard they have been divided into four categories based on appearance.
- Chinese White Bok Choi- this is a tall plant (30 cm at harvest) with thick green leaves and white stalks.
- Shanghai Bok Choi – has light green leaves and light green stalks and the plant is at harvest it about 15 cm high.
- Soup Spoon type - has cupped ladle-like leaves with white stalks and can grow up to 45 cm in height.
- Canton type - is a short squat type with convoluted dark green leaves and white stalks. Sometimes this type is harvested early as Baby Bok Choi.
Chinese chard has a range of uses in salads and as a cooked vegetable in stir-fries and casseroles. It has the ability to absorb other flavours so it can be used with a whole range of other foods.
It is a very quick growing crop and can be ready for harvest in 35-55 days after sowing, depending on the season. In the late autumn to early spring, it is recommended to grow the Chinese White Bok Choi and the Soup Spoon varieties but in the warmer months, the Shanghai and canton types are better suited.
Chinese chard is essentially a cool season crop preferring temperatures of about 15-20°C. The Canton types, however, are better suited to warmer climates, as in cooler areas they tend to "bolt" and go straight to seed. The Chinese White Bok Choi varieties also have this tendency to bolt. The other two types appear to be quite adaptable to a range of climates. Most types can tolerate light frosts, with the Shanghai types the most tolerant. Wind can affect production both in terms of yield and damage to leaves.
The planting density depends on the type. The larger varieties (Chinese White Bok Choi and Soup Spoon) are usually grown in 30 cm rows with 45 cm between plants. The smaller varieties are planted in 18-20 cm rows with 2.5-10 cm between plants. They can be direct seeded or transplanted as seedlings, either in outdoor raised beds or in greenhouses. Transplants are not often used because of the additional cost and problems with bolting.
Pests and diseases
Chinese chard is attacked by several pests and the most common pests are green looper caterpillars, cabbage caterpillars, cutworm, aphids, snails and slugs.
It can be infected by several diseases,
- Erwinia carotovora which causes a mushy decay of leaf petioles nearest the ground which is commonly found in decaying vegetable matter as it infects wounds. It thrives in hot weather.
- Albugo candida (white rust) causes a mass of small white, circular raised spots on both sides of the leaf and is common in cool wet weather Pseudocerosporella capsellae causes spots on the leaves
- Rhizoctonia causes mould on the stems Plasmodiophora brassicae (clubroot) incidence and severity may be reduced with the application of lime.
Harvesting is usually done by hand. The outside leaves are removed and the plants are usually in bunches of 2-3 plants. Chinese chard is easily bruised, so care needs to be taken when harvesting, handling and bunching. They should be cool-stored at temperatures of 0-2°C with high relative humidity between 90-100%. This can keep the vegetables in good condition for anything from 7-14 days, depending on the variety. Chinese chard can last up to 30 days in modified atmosphere packaging (MAP). Production levels vary according to management but common yields are usually about 15 tonnes per hectare.
Chew, M. and W. Morgan (1996) Melbourne retail Asian vegetable survey. Melbourne, Agriculture Victoria 143 pp.
Chew, M. and W. Morgan (1997) List of identified pests and diseases affecting Asian vegetables. Access to Asian Vegetables. (2): 1.
Fernando, N. (2010) Asian Vegetables, Agriculture Note, AG 0633, DEPI Victoria.
Moore, S., W. Morgan and M. Chew. (1998). Chinese chard. The New Rural Industries. Ed.: K. W. Hyde. Canberra, Rural Industries Research and Development Corporation, pp. 172-177.
Nguyen, V. Q (1992) Growing Asian vegetables. Agfact, NSW Agriculture H8.1.37.
Correct diagnosis is essential for effective pest and disease control. A commercial diagnostic service is available at the AgriBio Bundoora.
For further information, phone Crop Health Services on (03) 9032 7515.
This Agriculture Note was developed by Farm Services in June 2000.
It was reviewed by Neville Fernando, Farm Services in June 2012.
Published and Authorised by:
Department of Environment and Primary Industries
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