How to grow pak choy
Overview
Pak choy (Brassica rapa subsp. chinensis) is a cool-season leafy brassica grown for its crisp white stems and dark green leaves. Unlike heading brassicas, it forms an open rosette and is harvested whole or as cut-and-come-again. Success depends on steady growth without temperature extremes, especially heat that triggers bolting.
Varieties
- Bok Choy 'Shanghai Green' — Classic white-stemmed variety with large, dark green leaves, slow to bolt.
- Bok Choy 'Dwarf White Stem' — Compact plant ideal for tight spaces and containers, harvests in 45 days.
- Bok Choy 'Toy Choy' — Miniature variety perfect for baby leaf production and small gardens.
Soil Preparation
Prepare soil with plenty of well-rotted compost or manure to retain moisture and fertility. Ideal pH is 6.0–7.5. Ensure good drainage to prevent root rot; raised beds help in heavy clay soils.
Growing Guide
Sow seeds directly 1 cm deep in well-drained, fertile soil in full sun to part shade. Space plants 20–30 cm apart in rows 30–40 cm apart. Keep soil consistently moist; water at the base to reduce leaf disease. In warm weather, use shade cloth to delay bolting. Succession sow every 3–4 weeks for continuous harvest.
Sowing
Sow seeds 1 cm deep, 2–3 seeds per spot, then thin to the strongest plant. Germinates in 5–7 days at 10–25°C. Direct sowing is easiest, but seedlings can be transplanted carefully to avoid root disturbance.
Care
Feed every 2–3 weeks with a balanced liquid fertiliser (e.g., seaweed or fish emulsion). Mulch around plants with straw or sugar cane to retain moisture and suppress weeds. Remove yellowing or damaged leaves promptly to improve airflow.
Companion Planting
Good companions include carrots, onions, lettuce, peas, and dill, which share similar moisture needs and deter pests. Avoid planting after or near other brassicas (cabbage, kale, broccoli) to reduce soilborne disease risk.
Common Pests & Risks
Cabbage white butterfly caterpillars chew large holes; control with Bacillus thuringiensis (BT) or fine netting. Aphids cluster on new growth; blast with water or use neem oil. Flea beetles cause pinhole damage; apply diatomaceous earth or grow under insect mesh.
Harvesting
Harvest whole plants when they reach 15–25 cm tall, typically 6–8 weeks from sowing. Alternatively, pick outer leaves individually from 4 weeks, allowing the centre to continue growing. Cut stems near the base with a clean knife.
In the Kitchen
Use fresh in stir-fries, soups, and salads. Leaves and stems are both edible; the thick stems have a mild, juicy crunch. Store in a plastic bag in the fridge for up to a week; avoid washing until ready to use.
Troubleshooting
Yellow lower leaves: usually nitrogen deficiency or overwatering. Feed with liquid fertiliser or reduce watering. Bolting (premature flowering): caused by heat or transplant stress. Plant in cool season and shade from hot sun. Holes in leaves: cabbage white caterpillars or flea beetles. Use netting or BT spray. Stunted growth: often due to poor soil fertility or root competition. Side-dress with compost. Leggy seedlings: insufficient light. Thin and ensure 6+ hours of sun.