How to Grow Choy Sum Purple
Wikimedia Commons
Choy Sum Purple
Brassica rapa subsp. parachinensis
vegetableChoy Sum Purple is an Asian leafy green vegetable featuring dark purple stems and tender flowering shoots. It's a fast-growing brassica that produces edible flower buds, stems, and leaves with a mild, slightly sweet flavor. This variety is popular in stir-fries and Asian cuisine for its tender texture and nutritional value.
When should you plant Choy Sum Purple in your zone?
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Example Choy Sum Purple timeline · Pittsburgh, PA (Zone 6b)
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Plant Choy Sum Purple
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 Purple
Around Jun 1≈ 45 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Choy Sum Purple dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 5-9, with spring and fall cultivation ideal in warmer regions
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Get my Choy Sum Purple timeline →Growth Stages
Seedling
2-3 weeksSmall plants with 2-4 true leaves, emerging 5-10 days after sowing
Thin seedlings to proper spacing when 1-2 inches tall. Keep soil moist and provide bright light. Protect from drying wind.
Vegetative
3-4 weeksRapid leaf and stem growth with purple-tinged stems developing; plant reaches 8-12 inches tall
Water consistently, apply balanced fertilizer every 2-3 weeks. Monitor for pests. Remove any flower buds if extending vegetative stage is desired.
Flowering/Budding
2-3 weeksTender flower buds form at stem tips, resembling small broccoli florets with purple coloring and small yellow flowers beginning to open
This is the prime harvest stage. Maintain consistent moisture and continue light fertilizing. Harvest regularly to encourage more shoots.
Extended Flowering
1-2 weeksYellow flowers open fully on main stems and secondary shoots; plant becomes taller and more branched
Plants are still edible at this stage. Harvest young shoots with buds for best tenderness. Remove lower mature leaves to improve air circulation.
Senescence
OngoingFlowering continues, seed pods begin forming, stems become tougher and more fibrous
Harvest is declining in quality. Consider replanting for continuous supply. Can leave mature plants to set seed if desired.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Use row covers, hand-pick larvae, apply Bt (Bacillus thuringiensis), neem oil, or spinosad
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Install row covers early, use neem oil, apply kaolin clay, encourage beneficial insects
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Spray with strong water stream, apply insecticidal soap, use neem oil, introduce ladybugs
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Hand-pick adults and egg clusters, use row covers, apply neem oil or spinosad
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Avoid planting brassicas in same location for 4+ years, improve drainage, lime acidic soils, use resistant varieties
Uses
Stir-fries and Asian cuisine
CulinaryChoy Sum Purple is prized in Chinese, Vietnamese, and Southeast Asian cooking for its tender stems, delicate flower buds, and mild flavor. The entire plant including stems, leaves, and buds are edible and cook quickly in high-heat stir-fries. [source]
Nutritional superfood
CulinaryRich in vitamins A, C, and K, calcium, and dietary fiber. Contains glucosinolates and phenolic compounds with potential anti-inflammatory properties. Low in calories while providing excellent micronutrient density. [source]
Fresh and cooked preparations
CulinaryCan be blanched, steamed, sautéed, roasted, or added raw to salads when very young. The tender shoots pair well with garlic, ginger, sesame oil, and soy sauce. Flowers are edible garnishes. [source]
Succession planting and kitchen garden staple
HouseholdFast maturity (45-60 days) makes it ideal for continuous harvesting and succession planting every 2-3 weeks. Perfect for home gardeners seeking quick, reliable harvests in small spaces. [source]
Pollinator support
WildlifeFlowering choy sum provides pollen and nectar for bees, butterflies, and beneficial insects during its blooming stage. Letting some plants flower naturally supports garden ecology. [source]
Harvest Tips
Begin harvesting when flower buds are tender and tightly formed, before flowers fully open (45-55 days). Harvest in the morning for best crispness. Cut the main shoot first, 1-2 inches above soil, which encourages multiple side shoots. Continue harvesting secondary shoots over 2-3 weeks for extended production. Younger, thinner stems have superior texture. Use a sharp knife to avoid plant damage.
Fun Facts
- 🌱 Choy Sum Purple is a loose-heading Asian brassica that doesn't form dense heads like cabbage, making it lighter and more heat-tolerant than many brassicas.
- 🌱 The name 'choy sum' means 'vegetable heart' in Cantonese, referring to the tender flowering stems that are the most prized part of the plant.
- 🌱 Purple varieties contain anthocyanins, the same beneficial antioxidant pigments found in blueberries and red cabbage, giving them superior nutritional profiles compared to green choy sum.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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