Pak choi

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.

Frequently asked questions

When do you sow pak choi?

From mid-July to the end of August, sown straight into the bed about 1 cm deep. The late date has a reason: spring sowings almost always bolt, because cool nights and long days switch the plant to flowering rather than to a solid rosette.

Why is my pak choi bolting?

Cold is usually behind it: nights below about 10 °C in the first weeks switch the plant over to flowering, and the long days of early summer add to that. A bolted plant is still usable — the stems and closed buds fry up nicely.

When is pak choi ready to harvest?

From the start of September to about 10 November, a good six to eight weeks after sowing. You can take individual outer leaves earlier without stopping the plant — it keeps bulking up from the centre.

Is pak choi frost hardy?

It comes through light night frosts, but it is only half hardy and no winter crop. Harvest therefore ends around 10 November, and when a prolonged freeze is forecast it is better to bring the whole lot in at once.