Growing Pak Choi in Scotland: The Complete Guide

Brassica rapa (Chinensis Group)

Pak choi is a fast, forgiving oriental brassicaThe cabbage family: cabbage, kale, broccoli, cauliflower, Brussels sprouts, kohlrabi, swede, turnip and more, sharing the same pests, diseases and rotation rules. Full definition →, and its one real weakness happens to be a risk our climate rarely supplies.

It's ready in as little as 30 days for baby leaves, or 45 to 75 days for a full, compact head, which makes it one of the fastest crops you can grow. Its main failure mode is boltingA plant switching early into flowering and seed production, usually triggered by stress, after which leaves, roots or bulbs turn bitter or unusable. Full page → in hot, dry weather, and that's a threshold a Scottish summer rarely reaches, which puts this crop's biggest weakness largely out of reach here. It also handles cold better than most fast leaf crops, so a late sowing under cover can keep going well past the point most quick salads have finished.

Sowing and raising plants

Sow February to October, in successive small batches rather than one big row, about 2cm deep, in rows at least 30cm apart.

Raise it in modulesA tray divided into small individual cells, each sown with its own seed or seedling, so each plant grows undisturbed roots until it's ready to plant out. Full definition → rather than a seedbed. Pak choi dislikes root disturbance, so direct-sowing and thinning it the way you would lettuce or rocket sets it back more than the same treatment would on a less sensitive crop.

Move plants out once they're established, hardening offGradually getting young plants raised indoors used to outdoor conditions over 7–14 days before planting out, so cold, wind and direct sun don't shock or damage them. Full definition → first.

Bolting: the one thing to watch, and why it matters less here

Hot, dry weather is what triggers bolting on this crop, which is why spring and autumn sowings are the safer default and summer sowings want a bolt-resistant variety. Partial shade and consistent watering help further on the rare properly warm spell.

Varieties

RHS also lists 'Choko F1The first-generation offspring of two specific, deliberately chosen parent plants, bred for a predictable, uniform result but not worth saving seed from. Full definition →' (warm-weather tolerant) and 'Red Choi' (purple-red leaves) with AGMThe RHS's Award of Garden Merit: a UK-wide trials award for reliable performance, not a Scotland-specific recommendation. Full definition →. The award is UK-wide, not a Scottish one.

Also worth considering

Best Pak Choi Varieties for Scotland → compares all named pak choi varieties head-to-head, with the practical detail that doesn't fit in a summary card.

Spacing and watering

Space 8-10cm apart for baby leaves, 20cm for semi-mature, or 25-30cm for full-sized plants. Keep the soil consistently moist, and water in the morning rather than the evening: damp soil left overnight is exactly what draws slugs and snails, the biggest pest risk to this crop.

Harvesting

Baby leaves are ready as a cut-and-come-again crop in about 30 days. Semi-mature or full-sized heads take 45 to 75 days, harvested while still compact and firm. Late sowings, given a little protection from a clocheA small, portable clear cover placed over an individual plant or short row to trap warmth and keep off wind, rain and pests. Full definition → or fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition →, can keep cropping into autumn and even winter.

Common problems

• Slugs and snails are the main risk to this crop, especially direct-sown seedlings. Water in the morning rather than the evening, and raise plants in modules.
• Bolting is triggered by hot, dry weather. Favour spring and autumn sowings, and use a bolt-resistant variety for a summer one.
• Cabbage caterpillars can strip a plant fast. Cover with insect-proof mesh from sowing.

Common questions

Sources