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Bok Choy: How to Plant, Grow, and Harvest Bok Choy (Pac Choi) | Almanac.com

Bok Choy

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CreativeFire/Shutterstock
Botanical Name
Brassica rapa subsp. chinensis
Plant Type
Sun Exposure
Soil pH
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Learn how to plant, grow, and care for bok choy.

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Delicious and vibrant, bok choy (also known as “pak choi”) is a crisp, cool-season green harvested in spring and fall. It can easily tolerate a light frost, which improves its flavor! Learn how to plant, grow, and care for bok choy.

About Bok Choy

Bok choy are Brassicas, members of the cabbage family which also includes cauliflower, broccoli, and Brussels sprouts. Other common names include pak choi, pok choi, and Chinese cabbage. Their botanical name is Brassica rapa subsp. chinensis. They don’t form heads and grow stalks from a bulbous base, similar to celery. The stalks and the leaves are edible and are common ingredients in Asian-inspired cuisine. 

Bok choy is commonly purchased in the grocery or at the farmers’ market as full-sized or baby bok choy but they are the same plant. Baby bok choy is harvested when the plant is younger, giving it a tender and sweeter taste. Use baby bok choy in soups and salads and the larger, more sturdy plants in recipes like stir fry that require longer cooking.

These plants are biennials and can be prone to bolting. Bolting in the first year is commonly caused by cold weather followed by a period of rising temperatures, tricking the plant into thinking it has gone through a winter. Dry soil can also cause bolting, as can sustained hot summer weather. 

Planting

Bok choy is great news for gardeners who struggle to find enough sunny spots to plant all their veggies. While it grows well in full sunshine, bok choy will also grow well in partial sun, about 3-5 hours daily. 

In hot climates, planting in a spot with morning sun and afternoon shade helps to delay bolting. Save those super-sunny sites for your tomatoes or sweet corn!

Fertile, rich soil and a neutral pH is ideal for these heavy feeders. Work a generous amount of compost into the soil before planting. Leave space for succession plantings to extend your harvest. 

With its quick growing time and tolerance for light frosts, bok choy can be planted in your garden where earlier maturing crops are already finished.

When To Plant Bok Choy

Bok choy is not a fan of hot weather, so gardeners typically grow two crops, one in spring and another in fall. For spring plantings, start seeds indoors 4 to 6 weeks before your last spring frost date. For fall harvests, count backward 50 days from your first frost and direct seed.

If you garden in a frost-free or nearly frost-free zone, your bok choy growing season may be autumn, right through winter, and into the spring until high temperatures arrive. 

How To Plant Bok Choy

Bok choy is usually started from seed, but transplants can be bought in the spring at garden centers. Sow more every 2 weeks throughout spring and again in fall to achieve a long, continuous supply of these delicious plants.

To start bok choy indoors:
  • Sow 1-2 seeds per cell in standard trays or use soil blocks. 
  • Sow seeds about a ¼-½ inch deep. 
  • After germination, thin to one seedling per cell. 
  • Snip the extras, don’t pull them, or you might damage the roots of the remaining plants. 
  • Harden them off before transplanting them into the garden beds.
  • They can be transplanted outside once a set of true leaves has been established and soil temps outside are 50°F (10°C). 
To direct seed after the last frost in spring or in late summer:
  • Prepare the bed with compost.
  • Sow seeds ½ inch deep, about three inches apart, in rows 18 inches apart.
  • Once plants are 4 inches tall, thin to a spacing of 6-9 inches apart. Eat the ones you remove! 
Growing

Easy to grow and tolerant of partial sun, these plants are a surefire way to get some garden produce into your kitchen. 

  • Bok choy likes fertile, nitrogen-rich soil. Add lots of compost and organic matter.
  • Keep soil moisture even and slightly moist. Try to avoid extreme cycles of dry and wet.
  • Bok choy may bolt prematurely if exposed to cool night temperatures and the weather warms. Wait to transplant spring crops until the danger of frost has passed. 
  •  Bok choy likes an inch of water per week or more. Try to water in the morning. The plants will have water available during the hottest part of the day and be less stressed. If your mornings are hectic, consider a timer to turn your irrigation on and off.  
  • Mulch between plants after thinning to keep weeds down and moderate the soil moisture fluctuations.
Harvesting

Waiting too long to harvest is a common mistake. Start harvesting your bok choy when the plants are 12-15 inches tall. If you want baby bok choy, begin when they are smaller. Store harvested plants in a cool, dark place for up to a week.

Succession planting and harvesting of multiple-size plants can extend your bok choy harvest. With a bit of practice, you’ll enjoy fresh bok choy for many weeks every spring and fall. 
All above-ground parts are edible. Smaller plants are more tender. 

  • Use thinned plants in fresh salads, toss them into omelets and soups, or crunch on them for lunch. They are a sweet treat. 
  • Use a sharp knife and trim an inch or two above the soil. The remaining plant will likely sprout and grow a new, although smaller, bok choy.
  • Harvest a few plants for baby bok choy. The spacing created will allow the rest to keep growing larger. 
  • Baby bok choy can be harvested as soon as 30 days after planting, while others are left to grow to maturity. Some varieties will grow for 60-70 days in cool weather before reaching peak size. 
Wit and Wisdom
  • Bok choy can be protected from insects with row covers if they are eating your crop, but be sure to anchor it well, so it doesn’t flap in the wind and damage the plants.
  • Bok choy is low in calories but high in vitamins. It’s an excellent source of vitamins C, K, and A.
Pests/Diseases
Bok Choy Pests and Diseases
Pest/DiseaseTypeSymptomsControl/Prevention
AnthracnoseFungusYellow/brown/purple/black spots on leaves; sunken, dark spots on stems; spots may develop a salmon-pink, gelatinous mass; eventually, rotDestroy infected plants; choose resistant varieties; provide good drainage; avoid overhead watering; apply compost; use mulch; rotate crops
AphidsInsectMisshapen/yellow leaves; sticky “honeydew” (excrement); sooty, black moldGrow companion plants; knock off with water spray; apply insecticidal soap; put banana or orange peels around plants; wipe leaves with a 1 to 2 percent solution of dish soap (no additives) and water every 2 to 3 days for 2 weeks; add native plants to invite beneficial insects
Black rotFungusYellow, V-shape areas on leaf edges that brown and progress toward leaf center; leaves eventually collapse; stem cross sections reveal blackened veinsDestroy infected plants; choose resistant varieties; provide good drainage; remove plant debris; rotate crops
Cabbage loopersInsectLarge, ragged holes in leaves from larval feeding; defoliation; stunted or bored heads; excrementHandpick; add native plants to invite beneficial insects; spray larvae with insecticidal soap or Bt; use row covers; remove plant debris
Cabbage root maggotsInsectWilted/stunted plants; off-color leaves; larvae feeding on rootsUse collars around seedling stems; monitor adults with yellow sticky traps; use row covers; destroy crop residue; till soil in fall; rotate crops
CabbagewormsInsectLeaves have large, ragged holes or are skeletonized; heads bored; dark green excrement; yellowish eggs laid singly on leaf undersidesHandpick; use row covers; add native plants to invite beneficial insects; grow companion plants (especially thyme); spray Bacillus thuringiensis (Bt)
ClubrootFungusWilted/stunted plants; yellow leaves; roots appear swollen/distortedDestroy infected plants; solarize soil; maintain soil pH of around 7.2; disinfect tools; rotate crops
CutwormsInsectWilting; severed stems of seedlings and transplants just above or below soil line; whole seedlings disappearHandpick; in spring before planting, cultivate soil to reduce larvae; wrap a 4-inch-wide collar made from cardboard or newspaper around each stem, sinking 2 inches into soil; weed; use row covers; destroy crop residue
Downy mildewFungusYellow, angular spots on upper leaf surfaces that turn brown; white/purple/gray cottony growth on leaf undersides only; distorted leaves; defoliationRemove plant debris; choose resistant varieties; ensure good air circulation; avoid overhead watering
Flea beetlesInsectNumerous tiny holes in leavesUse row covers; mulch heavily; add native plants to invite beneficial insects
Powdery mildewFungusTypically, white spots on upper leaf surfaces expand to flour-like coating over entire leaves; foliage may yellow/die; distortion/stunting of leavesDestroy infected leaves or plants; choose resistant varieties; plant in full sun, if possible; ensure good air circulation; spray plants with 1 teaspoon baking soda dissolved in 1 quart water; destroy crop residue
Slugs/snailsMolluskIrregular holes in leaves; slimy secretion on plants/soil; seedlings “disappear”Handpick; avoid thick bark mulch; use copper plant collars; avoid overhead watering; lay boards on soil in evening, and in morning dispose of “hiding” pests in hot, soapy water; drown in deep container filled with 1/2 inch of beer, or sugar water and yeast, and sunk so that top edge is slightly above ground; apply 1-inch-wide strip of food-grade diatomaceous earth as barrier
StinkbugsInsectYellow/white blotches on leaves; eggs, often keg-shape, in clusters on leaf undersidesDestroy crop residue; handpick (bugs emit odor, wear gloves); destroy eggs; spray nymphs with insecticidal soap; use row covers; weed; till soil in fall
ThripsInsectLeaves, especially in folds near base, have white patches or silver streaks; brown leaf tips; blistering/bronzing on cabbage leaves; curling or scarringRemove plant debris; choose resistant varieties; add native plants to invite beneficial insects; use row covers; use straw mulch; monitor adults with yellow or white sticky traps; use sprinklers or other overhead watering
White moldFungusPale gray, “water-soaked” areas on stems, leaves, and other plant parts that enlarge and develop white, cottony growth, later with black particles; bleached areas; crowns rot; plants wilt/collapseDestroy infected plants; ensure good air circulation; water in morning; weed; destroy crop residue; rotating crops on 5-year or longer cycle may help