Plant Profile: Brassica rapa (Chinensis Group)

Pak Choi, part of the mustard family, encompasses a variety of widely cultivated plants, including pak choi, bok choy, Chinese celery cabbage, Chinese white cabbage, mustard cabbage, and choysum. These plants are typically annuals or biennials, characterized by their loose clusters of leaves atop a pale stalk. They are commonly grown for food, whether commercially or in home gardens.

The genus name, Brassica, is derived from Latin, meaning cabbage.

Pak Choi thrives in conditions ranging from full sun to partial shade and prefers moist, well-drained soil, with an ideal pH level between 6.0 and 7.5. Although growth may slow in lower light conditions, the plant can manage with as little as two hours of sunlight daily. To ensure optimal texture and flavor while preventing tip burn, consistent watering is essential, especially during dry spells.

For planting, spring or fall is ideal, utilizing fertile, moist soil. Seeds can be sown directly or transplanted, and since Pak Choi can withstand light frost, it is suitable for early spring or late fall planting. Seeds should be buried 1/4 to 1/2 inch deep, with plants spaced or thinned to 6 inches apart. Additionally, Pak Choi can be cultivated in containers that are at least 1 gallon in size and 20 inches deep. The plants typically reach maturity in about 60 days, and using row covers can help mitigate insect damage.

These plants are excellent choices for southern gardens in both spring and fall, allowing for harvesting at various stages—from young leaves to fully mature heads. For a continuous harvest, you can pick the largest outer leaves first. If the plant begins to bolt before you can harvest, you can still collect the head before the flowers bloom and use it as usual.

Common issues include pests such as aphids, whiteflies, flea beetles, and caterpillars like cabbage loopers, cutworms, and beet armyworms. Slugs and snails may also pose a threat. Diseases that affect Pak Choi include club root, white rust, leaf spot, and various rots, including damping off and bacterial soft rot.