Brassica rapa subsp. pekinensis

Sowing and spacing guidance

Brassica rapa subsp. pekinensis seeds prefer cool conditions and steady growth. Sow under cover for transplanting after last frost, or direct sow when soil is workable and temperatures are mild; a second sowing in late summer suits an autumn harvest, with autumn–winter sowing possible in mild climates. Choose full sun to light shade and fertile, well‑drained soil kept consistently moist. Sow shallowly, keep seedbeds evenly damp, and thin promptly to maintain generous spacing and good air flow as plants form medium-sized, dense heads. Avoid heat stress with light shade or fleece in warm spells. Mulch to stabilise moisture and reduce weed competition.

• Use fresh seed and sow in cool weather; protect early sowings and transplant after last frost.
• Thin in stages; maintain generous spacing and follow packet guidance for final plant distance.
• Keep soil evenly moist; mulch to conserve moisture and prevent checks to growth.
• Provide full sun to light shade; shelter from hot, drying winds to reduce bolting.
• Edible: grown for compact heads; harvest when firm and before leaves loosen.

When should I sow Chinese cabbage seeds?

Sow in cool weather. Start seeds under cover for transplanting after the last frost, or direct sow outdoors when soil is workable and temperatures are mild. A late-summer sowing often gives the most reliable autumn harvest; in mild climates, autumn–winter sowing is possible. Avoid the hottest, longest days to reduce bolting. Most cultivars mature in about 60–90 days from sowing, so time your sowing to allow heads to firm up before extreme heat or deep cold.

What is the ideal germination temperature for napa cabbage seeds?

Brassica rapa subsp. pekinensis seeds germinate best in cool to moderate soil, ideally 18–22°C, with a workable range of about 15–25°C. At these temperatures, seedlings usually emerge in 4–10 days. Sow 0.5–1 cm deep in evenly moist, well-prepared seedbeds or trays. Warmer than 25–27°C can lead to uneven germination and later stress, while cooler than 12–15°C slows germination significantly. Steady moisture and good air circulation help prevent damping-off.

Should I direct sow or transplant Chinese cabbage?

Both methods work, but direct sowing avoids transplant shock, which can trigger bolting. If transplanting, start seeds 3–4 weeks before set-out, grow in plugs or blocks to minimise root disturbance, and harden off for about a week. Plant out after the last frost when days are mild and stable. Set seedlings with 3–4 true leaves at the same depth they grew in the tray, water in well, and protect from sudden cold snaps. Use floating covers primarily for pest exclusion, removing or venting them during warm spells to prevent heat stress.

What spacing for Brassica rapa pekinensis, and how big do the heads get?

Allow generous spacing and good airflow; follow packet guidance for your cultivar. As a general guide, thin or plant 30–45 cm between plants with 45–60 cm between rows. For mini heads, 20–25 cm can work; for large, dense heads, 40–45 cm gives the best size and uniformity. Mature plants are medium-sized, often 25–35 cm tall, forming dense, elongated to barrel-shaped heads. Consistent moisture and mulching help heads fill tightly without splitting.

What are the soil requirements for Chinese cabbage, and how much sun does it need?

Grow in full sun to light shade; light shade can be helpful during warmer periods. Soil should be fertile, well-drained, and consistently moist, ideally with plenty of organic matter and a pH around 6.2–7.0. Prepare beds with compost and a balanced, moderate feed; avoid fresh, high-nitrogen inputs that can cause soft growth. Keep moisture steady with mulch and regular watering, avoiding both drought and waterlogging. In containers, use a deep, wide pot (around 20–30 litres per plant) filled with quality peat-free mix enriched with compost, and water carefully to maintain even moisture.

How do I prevent bolting in Chinese cabbage?

Sow at the right season and keep growth steady. Aim for cool, mild conditions; avoid heat spikes and prolonged cold that can vernalise seedlings. Maintain even moisture, provide light shade during warm spells, and do not overcrowd—good spacing and airflow reduce stress. Harden seedlings gradually and plant out only after danger of hard frost to prevent cold shock. Choose bolt-tolerant cultivars when available, feed modestly, and harvest promptly once heads are firm to prevent splitting and seedstalk formation.

Guidance is summarised from trusted horticultural sources and reflects general practice. Outcomes vary with microclimate, soil structure, and seasonal patterns; adjust to local cues such as sowing after last frost, when soil is workable, or in mild climates where autumn sowing may be possible. Where product information is available, product pages include specific instructions for sowing depth, spacing, and temperature ranges, which take precedence where details differ.

Growing Notes for Heading Brassicas

Heading brassicas thrive in cool conditions. Sow Brassica rapa subsp. pekinensis seeds when soil is workable and temperatures are steadily on the cool side. For spring (Northern Hemisphere) / autumn (Southern Hemisphere) heads, start after last frost; in mild climates autumn sowing may be possible for winter harvests. Provide fertile, well-drained soil with consistent moisture and even spacing to encourage tight, elongate heads. Sow shallowly and keep the surface evenly moist for uniform germination. Transplants shorten the window in short seasons, while direct sowing minimises disturbance to delicate roots. Mulch to moderate soil temperature; sudden warm spells can prompt bolting. Light netting or row covers help deter flea beetles and other leaf pests without sprays. Harvest when heads feel firm but before prolonged heat arrives. Succession sowing every two to three weeks extends the picking period and evens out supply. Good airflow and crop rotation support clean foliage and reliable hearting across varying climates.