How to Plant, Grow, and Harvest Bok Choy

How to Plant Bok Choy

When to Plant

Bok choy is a fairly fast-growing vegetable usually planted from seeds, either directly into the garden immediately after the danger of frost has passed or indoors about four weeks before the last frost. You can also plant nursery seedlings in the garden after the danger of frost has passed.

Timing is crucial when sowing seeds. If sown too late, warm weather can force the immature bok choy to bolt or set flowers and seeds. Bok choy will send up flower stalks if the weather is too warm or if exposed to temperatures below 50 degrees when young.

In areas with a cool spring that quickly shifts to warm temps, it may be best to start seeds indoors and then transplant the seedlings outdoors when all danger of frost has passed. You may have better luck avoiding bolting if you plant bok choy in the late summer or early fall when temperatures are fairly steady.

Selecting a Planting Site

The planting site must have well-draining, rich, fertile soil where rain can saturate the ground. It should also have full sun for most of the day, especially if it’s a fall crop. A spring crop, which is trickier due to the plant’s tendency to bolt because of temperature changes, should have three to five hours of full sun and partial shade, especially in the afternoon. Bok choy can also be grown in a container garden.

Spacing, Depth, and Support

Seeds should be planted 12 inch apart about 14 inch deep. If planting seedlings, space them in the ground 6 to 12 inches apart for adequate growth. If you are growing more than one row of bok choy, ensure your rows are 18 to 30 inches apart. If you want a continuous harvest, add new plants every two weeks.

No support system is necessary for bok choy.

Bok Choy Care

Light

Bok choy grows best in full sun but tolerates some of the shade, especially in summer. It typically needs about six hours of direct sun each day.

Soil

You’ll need well-draining soil enriched with organic matter. Bok choy will grow in a soil pH from 6.0 to 7.5, although something in the 6.5 to 7.0 range is best.

Water

Bok choy needs fairly moist but never soggy soil conditions. Drought can cause it to bolt to seed too early. Your plants will need consistent watering, especially in the drier fall months. The best rule of thumb is to give bok choy 1 inch of water a week so the soil remains moist between waterings.

Temperature and Humidity

Bok choy grows annually in every hardiness zone in the U.S. It does best in cooler weather; dry and hot conditions can cause it to bolt prematurely. This vegetable is not as winter-hardy as smaller-leaved Asian greens, but it may be winter-hardy under cover in USDA hardiness zones 4 to 7 during mild winters. However, it may quickly bolt to seed the following spring.

Fertilizer

When planting bok choy, add compost and organic fertilizer to the soil. These plants are heavy feeders, preferring soil rich in potassium, nitrogen, and phosphorus. However, organic feeding should be done at the time of planting, and chemical fertilizers should not be used during the growth period.

Types of Bok Choy

Bok choy contains vitamins A, B6 (folate), C, and K and minerals such as calcium, iron, and potassium. Although there are dozens of varieties of bok choy, many seed packets do not have a variety name.

Small “baby” bok choy is also a popular choice. It is the same as the larger variety, only harvested sooner, when smaller, for a milder, sweeter taste.

• ‘Black Summer’ has very dark leaves. It is planted in the fall and harvested in late fall or winter.
• ‘Ching-Chiang’ is a quick-growing dwarf that can handle early spring weather.
• ‘Joi Choi’ is a medium-sized plant with good bolt resistance.
• ‘Mei Qing Choi’ is a dwarf variety that grows quickly (35 days).
• ‘Win-Win’ is a cultivar with extra-large, dense heads; It is slow to bolt.

Bok Choy vs. Napa Cabbage

Bok choy and napa cabbage are both types of Chinese cabbage and are often confused. The two vegetables look alike, each having fibrous, long, coarse green leaves. Bok choy is more flavorful (and more bitter) than napa cabbage. Napa cabbage is crispier and grows larger than bok choy.

Harvesting Bok Choy

Depending on the variety and the weather, bok choy should be ready to harvest in 45 to 60 days after seed germination. Harvest leaves from the outer part of the plant to allow the inner leaves to continue growing.

When you’ve harvested what seems like all the leaves from plants, slice the plants off about 1 inch above the ground. They should re-sprout for you, or you can propagate them in water. The re-sprouted plants will be smaller but still delicious. The young, tender seedlings culled out during thinning can be added to salads or stir-fry dishes.

How to Grow Bok Choy in Pots

Bok choy can be grown in containers made of any material; they only require ample drainage holes. A pot should measure at least 12 inches wide and 20 inches deep for one plant. Add another 12 inches of width to the pot for additional plants.

Fill the pot with a lightweight potting mix that is well-draining but does not use regular dense soil. A good potting mix can be a mixture of peat, compost, and hopped bark that drains well. Place the pot where it will receive at least 6 hours of sun. Water the container regularly without letting the soil become dry to the touch. Water as close to the soil as possible without allowing moisture to hit the leaves.

Propagating Bok Choy

Propagating bok choy is a great way to make the plant’s scraps useful; then, you can toss the rest into the compost bin. The easiest way to propagate bok choy is to soak scraps in a jar or water bowl. Here’s how to propagate bok choy in water.

1. Use a large, sharp knife to chop the base of bok choy off from any remaining leaves. (A few small remaining leaves are fine.) The base should be about 2 to 3 inches tall. You can use a bok choy you’ve grown yourself or a stalk purchased at the store.
2. Put the base of the bok choy, facing up, in a shallow bowl filled with about 1 inch of clean, warm water.
3. Place the bowl on a sunny windowsill.
4. Change the water every other day or when it gets cloudy. To keep the base moist, try misting it every other day using clean water in a spray bottle.
5. The base will look like it’s dying in about a week but don’t throw it out. It will turn yellow, but the center will turn pale green and darker green.
6. A week or so later, the center will show leafy new growth. At that point, you must transfer the base to a pot filled with well-draining potting mix. Make sure the pot (any material is fine) has drainage holes.
7. Bury the base in the pot so only the tips of the new leafy growth stick out slightly.
8. Water the newly potted bok choy generously, but do not overwater or make the soil soggy.
9. If the timing is right, you can remove the new leafy base from its water and plant it in a container or outdoors.

How to Grow Bok Choy From Seed

Bok choy is a biennial, completing its growth cycle in two years. The first year, it grows its edible leaves; the second year, it’s grown for its flowers and seed heads. After flowering, remove the plants at the end of their lifecycle. Here’s how to grow the plant from its seeds:

1. If sowing directly into the garden, begin planting a week before your last frost date. Seeds are quick to germinate, usually within four to eight days.
2. Plant seeds 12 inch deep, spaced 1 inch apart.
3. You can also start seed indoors about four to five weeks before your last frost date. If you’ve started the seeds indoors, harden them off before planting.
4. Hold off transplanting them until nighttime temperatures remain above 50 degrees, or be prepared to cover them with garden cloth. If exposed to prolonged cold temperatures, the seedlings might start flowering or bolting.
5. Thin and eat the plants when they are a couple of inches tall.
6. If growing full-sized plants, thin to at least a 6-inches between plants.

Overwintering

Bok choy can handle some light frost or protection with a garden cloth during a cold snap; however, for locations with steady below-freezing winter weather, grow it as an annual.

Common Pests and Diseases

Bok choy is not usually affected by the most common brassica diseases. However, it attracts many insect pests, including cabbage loopers and worms. Flea beetles can riddle the leaves. Slugs, whiteflies, and aphids can also harm the leaves. Use row covers, garden fabric, or netting for outdoor plants to minimize damage from insects.