Pak choi (or bok choy, as it’s more often called in the US) is a type of Chinese cabbage. A sub-species of turnip, it’s part of the brassica family, along with broccoli, cauliflower, kale and other types of cabbage.
It’s commonly used lightly cooked in stir-fries or as a side dish. It can also be eaten raw as a salad leaf. The stems have a lovely crunchy texture, and the flavour is slightly mustardy.
Pak choi is a tidy, well-behaved vegetable that’s quite easy to grow and doesn’t take up a lot of space. It likes well-drained soil enriched with compost.
Pak choi doesn’t like the heat and the long days of mid-summer, and will tend to bolt at this time, so the best plan is to have two sowings: one in March/April and another in July/August.
Plant about 15 to 20 cm apart and keep well watered. For the March sowing, plant seeds in small individual pots of potting compost indoors. Keep them moist and when the plants are about 5cm tall they can be planted out into the vegetable patch, as long as the risk of severe frost has passed. For the July sowing this can be done outdoors, but it’s still advisable to start them off in little pots as slugs and snails love the little seedlings.
This year we have had brilliant weather so by the time we got to mid-June our pak choi started to bolt. This has not been a big problem for us as they’ve reached a reasonable size – still young enough to eat in salads but also substantial enough to use in stir fries. If you catch them before the bolting is too advanced there’s very little waste. The whole plant can be enjoyed raw or lightly cooked.
The second crop matures well with less risk of bolting, but the main problem this time is slugs (see pests below).
We use Vitax Organic Liquid Seaweed when planting out, and as a feed every fortnight at the height of the growing season. It’s rich in potassium, magnesium and trace elements. We’re also experimenting with Emiko EM-1 – a kind of probiotic for the soil. More about that at a later date.
You can either use the plants as cut-and-come-again – just taking the largest leaves from the outside – or leave entire heads to mature and pull them up whole. Baby leaf will be ready to pick within 3-4 weeks of planting out, and mature leaves within about 6 weeks.
The biggest danger for the early crop is greenfly. These can very quickly set up colonies on the underside of the leaves, so check carefully and frequently.
Slugs are a serious threat, especially later in the season. Pak choi has a lot of very cosy nooks and crannies between the leaves and little black slugs just curl up in there and munch away at the tender insides. You have to be diligent and carry tweezers around with you and look very carefully.
Another thing to watch out for is cabbage white caterpillars. The butterfly doesn’t lay eggs on pak choi but if your plants are near any brassicas the bright green caterpillars will be attracted to the lush leaves of the pak choi and are very hard to spot.
Downy mildew can be a problem when the weather is cool and damp. Make sure you give each plant enough space, so the air can circulate.