Growing Asian Vegetables: Pak Choi

This is the second installment in a series about my experiences growing Asian vegetables. You can find the other articles by clicking on the tag “Growing Asian Vegetables” at the bottom of this post.

Whether you call it pak choi, pac choi, or bok choy, this vegetable is an easy to grow and versatile member of the cabbage family. Known to have been cultivated in China since ancient times, its popularity has now spread throughout Asia and on to Europe and the Western world. In America, the white stemmed varieties are often seen in groceries and supermarkets, while Asian markets are also likely to have green stemmed and baby varieties available.

Home gardeners have quite a few varieties to choose from. Kitazawa Seeds, who specializes in Asian vegetable seeds, has fifteen different varieties listed this year. But pak choi is no specialty vegetable anymore. Even the more generalized seed purveyors like Johnny’s Selected Seeds and Nichols Garden Nursery each have five different varieties listed.

I’ve certainly not grown all of the varieties, but I’ve grown most of the different general types. Probably the most common are the white stem, green leaf varieties. Their sizes range from the 18” tall Joi Choi, to the miniature 5” tall Toy Choy, both of which are hybrids. Many of the open-pollinated varieties have names like “Medium Pak Choi” or “Extra Dwarf” that indicate the size of the mature plant.

I’m a little more partial myself to the green stem types, like the open pollinated Shanghai. Mei Qing was one of the first hybrids of this type and was bred for both cold and heat tolerance as well as resistance to bolting. I’ll talk more about the bolting issue later. Brisk Green and Black Summer hybrids are similar to Mei Qing, with slightly different heights and coloration.

There are also quite a few specialty pak chois that have been developed in recent times. Golden Yellow Hybrid lives up to its name with yellowish-green leaves and stems. Varieties like Purple Choi Hybrid, Violetta, and Red Choi add a touch of purplish-red to salad mixes when harvested at the baby leaf stage. The purple leaf varieties have been touted as being more nutritional, but be aware the color does fade when they are cooked.

One reason Pak Choi is so versatile is that it can be used at any stage of growth. Even large varieties like Joi Choi can be harvested when still small. And when the plant bolts to flower, the leaves remain edible, while the flowers and shoots are tasty as well.

In general, the various Pak Chois usually prefer cooler growing conditions, though some varieties have been adapted to hotter weather. Shanghai and Mei Qing do well in our hot summers here in zone 6, while Hanakan and San Fan are reported to tolerate hot conditions but not the cold. Many of the varieties do have good frost tolerance, and smaller plants frequently survive temperatures down to 20F here when protected. It does pay to read the catalog descriptions with all Pak Choi varieties, since some do better under specific growing conditions.

Pak choi is biennial in growth, but will run to seed sooner if stressed. The bolting problem is most apparent in spring. As with Chinese Cabbage, it is thought that exposure to temperatures below 50F may bring on flowering in some varieties, while other varieties may flower in response to the lengthening daylight. Heat or water stress may also cause bolting. The best defense is to plant bolt-resistant varieties, and keep the plants growing well and without being stressed.

Pak Choi may be grown from transplants or seed may be sown in place. One strategy is to sow seeds thickly, with some plants harvested at the baby stage and others left to mature. Like lettuce, Pak Choi has a fairly shallow root system, and appreciates a fertile soil with good moisture retention. It does well with dense plantings, which also serve to conserve moisture by shading the soil and reducing weed competition. Flea beetles, and cabbage caterpillars love to feast on the leaves. Floating row cover material will help to keep both pests under control. Slugs can also be a problem.

Individual leaves of Pak Choi may be harvested as needed, or the whole plant may be harvested. If cut just above the soil line, the plant will usually resprout and grow from the roots.  Several harvests can then be had from one planting.

Pak choi may be cooked in many ways: stir-fried, added to soups, grilled, or steamed. It can also be eaten raw. The leaf stalks are juicy and crisp, especially in the white stemmed varieties. The green stalks  tend to have more flavor than the white ones, and the leaves of all varieties have more flavor than the stalks.

If you’ve never grown pak choi, you might consider giving it a spot in your own garden. With so many varieties to choose from, there’s bound to be one that suits your tastes. I’ll be back again soon with another installment.