How to Grow Choy Sum
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Choy Sum
Brassica rapa subsp. parachinensis
vegetableChoy sum, also known as Chinese flowering cabbage, is a leafy green vegetable featuring tender stems, leaves, and small yellow flower buds. This nutritious brassica is a staple in Asian cuisine, prized for its mild, slightly sweet flavor and delicate texture. It grows quickly and produces multiple harvests when managed properly.
When should you plant Choy Sum in your zone?
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Example Choy Sum timeline · Pittsburgh, PA (Zone 6b)
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Plant Choy Sum
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Choy Sum
Around Jun 1≈ 45 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Choy Sum dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; grows year-round in zones 9-10
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Get my Choy Sum timeline →Growth Stages
Seedling
2-3 weeksTiny seedlings with 2-4 true leaves emerge within 7-10 days. Young plants are delicate with thin stems.
Keep soil evenly moist, provide bright light, thin seedlings to proper spacing to reduce competition. Protect from strong winds.
Vegetative
3-4 weeksRapid leaf and stem development; plant grows into a bushy form with 6-10 leaves and thickening stems. Green coloration deepens.
Maintain consistent moisture and temperature (65-75°F ideal). Apply balanced fertilizer every 2-3 weeks. Monitor for pests closely.
Bud Formation
1-2 weeksSmall yellow flower buds form at leaf axils and stem tips. Plant reaches 8-12 inches tall with dense foliage.
Continue regular watering and feeding. Buds are the most tender and desirable part for harvest. Increase nitrogen if needed for vigor.
Flowering
1 weekBright yellow flowers open if left unharvested. Plant becomes taller and more elongated as energy goes to flowering.
Harvest before or just as flowers open for best flavor and texture. Allow some plants to flower for succession planting seeds.
Harvest/Senescence
2-4 weeksAfter main harvest, secondary side shoots emerge from lower leaf axils. Plant may regrow for 2-3 additional smaller harvests.
Cut main stems carefully to encourage lateral growth. Continue watering and fertilizing for regrowth. Remove any yellowing leaves.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Hand-pick larvae, use Bacillus thuringiensis (Bt), row covers on young plants, neem oil spray
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Row covers, insecticidal soap, neem oil, reflective mulch, avoid overhead watering
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Strong water spray to dislodge, insecticidal soap, neem oil, encourage beneficial insects like ladybugs
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Yellow sticky traps, insecticidal soap, neem oil, reflective mulch
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Crop rotation (3-4 years away from brassicas), raise soil pH above 7.2, remove infected plants, disinfect tools
Uses
Stir-fry and Quick Cooking
CulinaryThe tender stems, leaves, and flower buds cook quickly in 3-5 minutes and are perfect for stir-frying with garlic and oil. The mild, slightly sweet flavor complements both Asian and Western cuisines. [source]
Steaming and Blanching
CulinarySteam or blanch choy sum for 2-3 minutes to preserve nutrients and bright color. Serve with oyster sauce, soy sauce, or sesame oil as a simple side dish. [source]
Nutritional and Antioxidant Benefits
MedicinalRich in vitamins A, C, K, and minerals including calcium and iron. Contains glucosinolates and other compounds with potential anti-cancer and anti-inflammatory properties. [source]
Fresh Produce Storage
HouseholdStore unwashed choy sum in a plastic bag in the refrigerator for up to 3-5 days. Can be blanched and frozen for longer storage. [source]
Pollinator and Beneficial Insect Support
WildlifeAllow some plants to flower; the yellow blooms attract bees, butterflies, and beneficial insects that help control garden pests. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
Harvest 45-60 days after planting or when stems are 6-10 inches tall with flower buds just forming but not yet opened. Cut main stem 1-2 inches above soil line with a sharp knife; secondary stems will sprout for additional harvests. Harvest in early morning for best crispness. Pick regularly to encourage continued production. Choy sum is best used fresh within 2-3 days of harvest.
Fun Facts
- 🌱 Choy sum is also called 'Chinese broccoli' in Western markets, though it differs significantly from broccoli in both botanical classification and flavor—it's actually closer to bok choy.
- 🌱 In traditional Chinese medicine, choy sum is considered cooling and beneficial for liver health, often featured in springtime wellness dishes.
- 🌱 A single planting can produce 2-4 successive harvests if managed as a cut-and-come-again crop, making it exceptionally productive for small garden spaces.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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