Brassicas
Pak choi
Brassica rapa subsp. chinensis
Timings for your region
Suggested: Moderate · Explained in the glossary
Sow outdoorsmid July – late August
Harvestearly September – early November
Practical tip
Reliable as a late-summer sowing; in spring it almost always bolts. Fast growing — six to eight weeks from sowing to harvest.
Origin & history
Pak choi has been grown in China for over a thousand years and botanically belongs not to the cabbage line but to the turnip one — the same species as Chinese cabbage and the May turnip. The name is Cantonese and simply means “white vegetable”, referring to the broad white leaf stalks. It only arrived in German gardens in recent decades, along with Asian cooking.
Varieties
There are white-stemmed types with broad, spoon-like stalks and the more delicate green-stemmed “Shanghai” types, which stay more compact and cook faster. For the summer and late-summer sowing variety choice hardly matters; anyone attempting a spring sowing despite the long days needs varieties explicitly sold as bolt-resistant. Baby or mini varieties are cut whole at around 15 cm tall and suit boxes and narrow beds well.
Care
Pak choi is sown direct and thinned to 25 cm once it is up — the thinnings are already salad. It takes root disturbance badly: pricking out and transplanting is the commonest reason for plants that throw a flower stalk instead of a rosette. Keep it evenly moist; a dry spell makes the leaves tough and bitter, and in such a short growing time the plant never catches up. From mid-October a fleece extends the harvest by two or three weeks.
What can go wrong
Flea beetles are the main problem of a summer sowing: they riddle the young leaves with tiny holes and like dry, warm surfaces — netting laid straight after sowing plus evenly moist, mulched soil takes that away from them. Slugs head for germinating pak choi rows first; collect them at dusk, water in the morning rather than the evening, and keep the bed edges short. And although it does not look like cabbage: pak choi belongs in the same rotation and must not follow other brassicas directly.
Harvest, storage & kitchen
Harvest the whole rosette with one cut just above soil level; leave the stump in place and in a mild autumn it will often push out a second tender flush. Pak choi wilts fast and keeps about a week in a bag in the fridge — there is no point storing it, but it takes well to lacto-fermenting. When cooking, separate stalks from leaves: the stalks need a few minutes, the leaves only seconds.
All timings are guide values for the given climate, not a guarantee. Weather, aspect and variety all have a say.