When should I sow pak choi in the UK?

Main sowing window: late July to early September for autumn–winter cropping (best results in UK). Spring sowings (March–April) work but bolt fast as days lengthen towards mid-summer. Avoid May–July sowings — long summer days trigger bolting before heads form properly.

Why does my pak choi bolt before forming a head?

Long summer days (above 14 hours of daylight) trigger bolting in pak choi. UK summer day length is the wrong frame for it. Sow in late summer for autumn cropping when days shorten; that gives the heads time to form before flowering. Bolt-resistant cultivars (Joi Choi, Choko) help but don't eliminate the problem.

What's the difference between pak choi, tatsoi and bok choy?

Pak choi (also spelled bok choy in some regions): tall upright form with white or green stems and broad leaves. The classic Chinese stir-fry green. Tatsoi: dark green rosette form with spoon-shaped leaves; flatter habit, more cold-tolerant; same species, same general care. Joi Choi, Rosie, Joi Choi F1: cultivar names for pak choi types. All are Brassica rapa subsp. chinensis.

How do I stop flea beetle on pak choi?

The dominant young-plant pest. Cover with fleece or fine enviromesh for the first 4 weeks after sowing — the flea beetles can't reach the leaves. Yellow sticky traps catch a useful number. Established plants tolerate the damage and outgrow it; the first 4 weeks are the critical window.

Can I grow pak choi in containers in the UK?

Excellent for containers. A 30 cm pot grows 4–6 plants. Use peat-free compost; water daily in summer; net against cabbage white and flea beetle. Containers actually help with bolting because you can move them into shade in hot weather — useful for spring sowings.

When and how do I harvest pak choi?

5–6 weeks from sowing. Cut whole heads at ground level when 15–20 cm tall and firm. Or pick outer leaves continuously from 4 weeks after sowing for cut-and-come-again use. Eat fresh — pak choi doesn't store well, soft within a week of picking.

Pak choi / bok choy

Brassica rapa subsp. chinensis

Sow pak choi seed direct from late July to early September for autumn–winter cropping; spring sowings (March–April) work but bolt rapidly in long summer days. Pak choi is hardy (RHS H4–H5) and one of the fastest brassicas — 5–6 weeks from sowing to harvest. Plant 20 cm apart in moist fertile soil with sun for half the day. Net against cabbage white through summer and flea beetle on young leaves. Pick whole heads when 15–20 cm tall, or take outer leaves continuously for cut-and-come-again. The classic stir-fry green; juicier and milder than spring cabbage; tolerates light frost. Joi Choi, Choko, Tatsoi (a different cultivar group with darker rosette leaves), and Rosie F1 (red-stemmed) are reliable UK choices.

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