PlantSowGrow
How to grow Choy Sum
Brassica rapa var. parachinensis
Grown for its tender flowering shoots, yellow buds and leaves — Cantonese "flowering cabbage", steamed or stir-fried.
At a glance: Sow late May to mid August, harvest from mid July.
When to sow, plant and harvest
Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.
Growing Choy Sum: what it needs
- Light
- Full sun · 6+ hours a day
- Watering
- Water regularly in dry weather
- Soil
- Fertile, well-drained soil
- Spacing
- 15 cm
- In pots
- Grows well in containers
- Feeding
- A general feed before sowing or planting
- Harvest
- About 50 days from sowing
- Hardiness
- USDA zones 3–9
- Difficulty
- Easy
Step by step
- Late May – mid August · 6 weeks after the last spring frost
Sow Seeds Outdoors
Sow thinly in drills where they are to grow.
- 4–10 days after “Sow Seeds Outdoors” · Early June
Check Germination
Seedlings should appear in 4–10 days. If sown outdoors, thin to 15 cm apart when big enough to handle.
- 0–3 days after “Check Germination” · Early June
Net Against Pests
Cover with fine insect mesh or netting straight after planting to keep off pigeons, cabbage white caterpillars and flea beetles.
- 40–61 days after “Check Germination” · Mid July – early August
Start Harvesting
Cut the stems when the first yellow flowers open; side shoots follow for a second picking.
- 14–28 days after “Start Harvesting” · Late July – early August
Sow Another Batch (optional)
Sow a little every three weeks for a steady supply.
- 30–60 days after “Sow Another Batch” · Late August – late September
Finish and Clear
Clear the remains to the compost heap once cropping ends.
