Choy sum
Choy sum (Brassica rapa var. parachinensis) is a plant. It grows best in full sun and has moderate water needs.
About Choy sum
Choy sum is a biennial plant that grows 30 cm tall. It grows fast. It is self-fertile, so you only need one.
The flowers attract pollinators.
How to plant choy sum
Choy sum does best in full sun, but also copes with part shade. It grows in sandy soil, loam and clay, as long as the soil is well drained. It does best at a pH of 5.5–7. In a forest garden it belongs in the herb layer.
Plant plants 10 cm apart, at least 5 cm. It struggles in compacted soil, so keep the soil loose.
A year with Choy sum
Spring. Water during dry spells in March. Sow seed in April–September. Keep the ground around it weed-free in April and May. Feed it in April. Use a balanced fertiliser. It has yellow flowers in May. Water during dry spells in May–September.
Summer. Harvest falls in June. The leaves can be eaten. The flowers can be eaten too. The seeds can be eaten too. Recorded from the source text, not a safety check. Confirm with a trusted guide before eating anything.
Autumn. Protect it from frost and cold in September–November. Harvest falls in November and December.
Pests and diseases
Choy sum can be attacked by small white butterfly (pieris rapae) and slugs. Diseases include clubroot and downy mildew.
Companions and wildlife
Choy sumThe family
Choy sum is a variety of Turnip, in the genus Brassica. Open a species to see what lies under it.
Choy sumvar. parachinensisThis page
Sources
Added to the wiki 12 October 2026
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