Choy Sum (Sawi Bunga)
Brassica rapa var. parachinensis
Malay names: Sawi Bunga, Choy Sum
Rapid leafy brassica with edible flower stalks; excellent yields in NFT/DWC.
🌞 Light & Temperature
Light: Bright light to full sun (4–6 h)
Temperature: 20–32°C
🪴 Container & Medium
Container: NFT/DWC; 2 inch net pots; 20–25 cm spacing; shade 30–50% in heat.
Medium / Solution: Medium: clay pebbles/rockwool; Solution: pH 5.8–6.5, EC 1.5–2.0 mS/cm
💧 Watering / Solution Maintenance
Schedule: Top-up daily; change every 7–10 days
Top-up: Maintain EC with water top-ups first
pH 5.8–6.5; EC 1.5–2.0 mS/cm
🧪 Nutrients
Type: Leafy nutrient; add Ca/Mg if tip burn
Frequency: Check EC 2–3x/week; change 7–10 days
Dosage/EC: EC 1.5–2.0 mS/cm; pH 5.8–6.5
🍓 Harvest
Start: 4–6 weeks from sowing
Seasonality: Year-round; best in drier months
Duration: 2–3 week harvest window
Harvest Indicators: Flower stalks elongate; buds still tight; leaves tender
Tips: Cut central stem first; harvest before open flowers for best texture.
🌱 Propagation
Seeds; thin to one per site.
🐛 Pests & Diseases
- Caterpillars/whiteflies: Netting; hand-pick; neem 1%.
🌦️ Seasonal Notes (Malaysia)
Shade and airflow reduce disease in monsoon.
📝 System Notes
Space 20–25 cm; avoid overcrowding.
💡 Extra Care Tips
- Harvest promptly at budding stage
- Mulch channels from sun to reduce algae
Note
EC and pH are guidelines—adjust to plant response and your water source. In monsoon humidity, increase airflow and reduce overcrowding to limit disease.