Bok Choy and Chinese Cabbage

Brassica rapa (pekinensis group) (Brassicaceae or cabbage family)

Production

---

Soil preparation

• Chinese cabbage planted in late summer does well after a spring seeding of bell beans and forage peas.
• Chinese cabbage shouldn’t follow other members of the Brassica family.
• Average nutrient uptake is 165 lbs. of N, 10 lbs. of P and 208 lbs. of K.
• Spread lime as needed to increase both the pH and Ca levels. Dolomite lime will also increase Mg levels. Spread gypsum when calcium levels are low but pH is correct.
• Apply compost and other amendments based on the results of a soil test.
• A fertilizer company can add OMRI-listed potassium sulfate to compost if it doesn’t have enough K to meet the crop’s needs. If this isn’t possible, spread the correct amount of fertilizer and incorporate it before planting. Alternatively, you can side-dress it during cultivation. Divide the recommended rate of the soil test in half if side-dressing. 
• Test for boron and apply only as recommended by the soil test. A fertilizer company can add boron to compost to optimize boron distribution. If this isn't an option, distribute soluble boron through a water solution with a sprayer directly on the soil. If applied directly on the crop, don't exceed more than 1 lb. of boron per acre to avoid leaf burn. 

Common recommended fertilizer rates¹

Nitrogen	Phosphorus	Potassium	pH
120	0-160	0-200	6.2-6.5
1Rates are for New York and are from Cornell University’s Nutrient Guidelines for Commercial Vegetable Production (2019). Check the Cornell website for updated guidelines, or consult with local experts for recommended rates outside New York.

Varieties

• Rubicon, Minuet, Bilko

Greenhouse guidelines

• EZ Seeder seeding plate # 16

Cell pack tray	Germination temp	Growth temp	Hardening off	Notes
72, 98 or 128	75°–90°	65°–75°	Reduce water	Put plug trays on a wire mesh bench to encourage air pruning. Take plants outside 1 week before planting in field.

Number of successions

• Spring: Chinese cabbage does poorly during hot and dry weather. Plant Chinese cabbage 2–4 weeks before the last frost date. Depending on your markets, plant each week for a continuous harvest in spring and early summer. In New York, this is limited to 2–3 successions.
• Fall: Chinese cabbage does better as a fall crop. In New York, seeding is resumed in July on a weekly basis until 4–5 weeks before the first frost, for a continuous harvest until November.

Transplanting in 5- or 6-foot beds

Rows	In-row spacing	Planting depth (inches)	Notes
2	12-15 inches	Don’t bury the plug; the top of the plug should be level with the soil to avoid leaves touching the soil.	Use a 12- or 15-inch sprocket or planting wheel. Irrigate after planting, and scout for flea beetles. When present, use row covers immediately.

Signs to watch for and what to do

• Harden plants off outside; plants that are lush don’t perform well in the field.

Transplant readiness indicators

• Plants are ready when they come easily out of the cell. Plants should generally not be older than 5 weeks.

Cultivation procedures (when transplanted)

• Use a basket weeder or wheel hoe when weeds are in the white thread stage, without burying the young crop. Weed control is more effective when you eliminate weeds before they emerge.
• Hand hoe in between plants.
• For a second cultivation use only sweeps or a hand hoe, and don’t hill. Slight hilling or aggressive cultivation can damage the shallow roots and affect growth.

Cultivation procedures (when direct seeded)

• Prepare the seedbed 1–2 weeks in advance, and shallowly stale seedbed before planting, to eradicate weeds if possible. Don’t disturb the soil too deeply, as this will bring new weed seeds up to the surface.
• Hand hoe in between plants. Thin when necessary.
• For a second cultivation, use only sweeps or a hand hoe, and don’t hill. Slight hilling or aggressive cultivation can damage the shallow roots and affect growth.

Insect protection

• Control black rot (Xanthomonas) by purchasing clean seeds, keeping the greenhouse clean and exposing seeds to hot water treatment. Some organic seed suppliers are hot treating their seeds these days, so check with them before applying your own treatment, as double treatment can affect germination.
• Flea beetles
  • Cover the crop with floating row covers or insect netting after transplanting to avoid flea beetle damage. Keep covered until harvest. Alternatively, use a spinosyn-based product like Entrust. 
  • If possible, follow Extension bulletins that publish the timing of each generation of flea beetles, or place yellow sticky cards at plant height to monitor their presence. Check the cards at least twice a week.
  • Spray beneficial nematodes on heavily infected land to control flea beetle grubs and avoid future generations. Flea beetles tend to overwinter in nearby hedgerows and grass strips.
• You can prevent cutworms by spraying the soil with the beneficial nematode Steinernema carpocapsae. Once the pest is in the crop, control the population by spraying the crop with Bacillus thuringiensis kurstaki, or spread a baited product containing spinosyn, like Seduce, around the plants.
• Cabbage maggots: To reduce infestation of cabbage maggots on young seedlings, cover seedlings with floating row covers or insect netting as you would for flea beetles. Maggots appear in 3–4 generations in the Northeast, starting in early spring.
• Scout for the eggs of imported cabbage worms or diamondback moths on the underside of leaves. When the small worm population is over 2 per plant, spray a Bacillus thuringiensis (Bt aizawai or Bt kurstaki) product, such as XenTari, or a spinosyn-based product, such as Entrust, every week until the population is under control. Alternate your spraying schedule by using Bt products along with a spinosyn-based product to avoid resistance buildup.
• To control cabbage leaf miners in a high tunnel, you can release a beneficial wasp (Diglyphus isaea), but in the field, only row covers or the use of a spinosyn-based product have proven to be effective.
• Basal stem rot (Erwinia carotovora), not to be confused with Rhizoctonia, is caused by insects eating at the basal stem. Damage from cultivation can also help bring this disease to the plant. Aggressive cultivation is not advised in Chinese cabbage production.
• Rhizoctonia, or bottom rot, can be an issue with Chinese cabbage and bok choy. Don’t allow lower parts of plants to be in contact with the soil, and plant it in a long rotation with other members of the brassica family. Transplanting when soil is at least 55F, reducing irrigation and dipping plants in Trichoderma harzianum, as in the product Rootshield, are good preventive measures.
• To avoid Alternaria leaf spot, plant far away or upwind from earlier planted cole crops and avoid overhead irrigation. Regular applications of Bacillus amyloliquefaciens, available as Double Nickel, have shown the best controls in research. Bacillus subtilis, available as Serenade, and mineral oil like JMS Stylet-Oil has shown some control for a few growers. Regular sprays with giant knotweed extract, such as Regalia, appear to reduce Alternaria as well, by activating the plant’s natural defenses against fungal and bacterial diseases.

Other cultural practices

• Irrigate frequently for optimum yield and plant health. Frequency depends on soil type, evaporation, precipitation and the particular needs of the crop. 

Double cropping and/or cover cropping

• You can plant a short-season, transplanted vegetable crop such as lettuce after early-planted Chinese cabbage.
• For later dates, work under any harvest remains to avoid insect or pathogen build up, and plant a cover crop. In the northern United States and Canada, you can follow summer- and early-fall-harvested Chinese cabbage with a cover crop of oats and peas in September, or rye and vetch planted at later dates. Adjust accordingly in other regions.

Production, Baby Bok Choy

---

Soil preparation and rotation

• Total nutrient uptake is 165 lbs. of N, 10 lbs. of P and 208 lbs. of K.
• Apply compost and other amendments based on the results of a soil test.
• Spread lime as needed to increase both the pH and Ca levels. Dolomite lime will also increase Mg levels. Spread gypsum when calcium levels are low but pH is correct.
• A fertilizer company can add OMRI-listed potassium sulfate to compost if it doesn’t have enough K to meet the crop’s needs. If this isn’t possible, spread the correct amount of fertilizer and incorporate it before planting. Alternatively, you can side-dress it during cultivation. Divide the recommended rate of the soil test in half if side-dressing. 
• Test for boron and apply only as recommended by the soil test. A fertilizer company can add boron to compost to optimize boron distribution. If this isn't an option, distribute soluble boron through a water solution with a sprayer directly on the soil. If applied directly on the crop, don't exceed more than 1 lb. of boron per acre to avoid leaf burn. 
• Incorporate compost and amendments, and plant Joi Choi or Mei Qing Choi in raised beds.

Common recommended fertilizer rates¹

Nitrogen	Phosphorus	Potassium	pH
120	0-160	0-200	6.2-6.5
1Rates are for New York and are from Cornell University’s Nutrient Guidelines for Commercial Vegetable Production (2019). Check the Cornell website for updated guidelines, or consult with local experts for recommended rates outside New York.

Varieties

• Li Ren Choi, Red Choi, Fujo Chomi, Mei Qing Choi, Win-Win Choi

Greenhouse guidelines

• EZ Seeder seeding plate #16

Cell pack tray	Germination temp	Growth temp	Hardening off	Cell pack tray
72, 98 or 128	65-85°	Cool	Withhold water	Put plug trays on a wire mesh bench to encourage air pruning. Take plants outside 1 week before planting in field.

Number of successions

• Spring: Baby bok choy doesn’t do well during hot and dry weather. Plant cabbage 4–5 weeks before the last frost date. Depending on your markets, plant each week for continuous harvest from spring to early summer. In New York, this is limited to 2–3 successions. 
• Fall: Baby bok choy does best as a fall crop. In New York, seeding is resumed in July on a weekly basis until 4–5 weeks before the first frost for continuous harvest until November.

Transplant readiness indicators

• Plants should easily come out of their cells. Plants should generally not be older than 5 weeks.
• Harden plants off outside; plants that are lush don't perform well in the field.

Transplanting in 5- or 6- foot raised beds

Rows	In-row spacing	Planting depth (inches)	Notes
3-4	10-12 inches	To avoid bottom rot, do not plant too deep	Bok choy does not like to be transplanted, so take great care of plants and plant in the afternoon.

Cultivation procedures

• Use a basket weeder or wheel hoe when weeds are in the white thread stage, without burying the young crop. Weed control is more effective when you eliminate weeds before they emerge. 
• Hand hoe or hand weed in between plants.
• For a second cultivation, only use side knives to avoid crop damage.

Frost, disease and insect protection

• Flea beetles
  • Cover the crop with floating row covers or insect netting after transplanting to avoid flea beetle damage. Keep covered until harvest. Alternatively, use a spinosyn-based product like Entrust. 
  • If possible, follow Extension bulletins that publish the timing of each generation of flea beetles, or place yellow sticky cards at plant height to monitor their presence. Check the cards at least twice a week.
  • Spray beneficial nematodes on heavily infected land to control flea beetle grubs and avoid future generations. Flea beetles tend to overwinter in nearby hedgerows and grass strips.
• You can prevent cutworms by spraying the soil with the beneficial nematode Steinernema carpocapsae. Once the pest is in the crop, control the population by spraying with Bacillus thuringiensis kurstaki, or spread a baited product containing spinosyn, like Seduce, around the plants.
• Cabbage maggots: To reduce infestation of cabbage maggots on young seedlings, cover seedlings with floating row covers or insect netting as you would for flea beetles. Maggots appear in 3–4 generations in the Northeast, starting in early spring.
• Scout for the eggs of imported cabbage worms or diamondback moths on the underside of leaves. When the small worm population is over 2 per plant, spray a Bacillus thuringiensis (Bt aizawai or Bt kurstaki) product, such as XenTari, or a spinosyn-based product, such as Entrust, every week until the population is under control. Alternate your spraying schedule by using Bt products in conjunction with a spinosyn-based product to avoid resistance buildup.
• Rhizoctonia, or bottom rot, can be an issue with Chinese cabbage and bok choy. Don’t allow lower parts of plants to be in contact with the soil, and apply long rotations that avoid other members of the Brassica family. Good preventive measures include transplanting when the soil is at least 55°, reducing irrigation, and dipping plants in Trichoderma harzianum, as in the product RootShield.
• Basal stem rot (Erwinia carotovora), not to be confused with Rhizoctonia, is caused by insects eating at the basal stem, but damage by cultivation can also help bring on this disease. Avoid aggressive cultivation in bok choy production.

Other cultural practices

• Irrigate frequently for optimum yield and plant health. Frequency depends on soil type, evaporation, precipitation and the particular needs of the crop. 

Double cropping and/or cover cropping

• You can transplant a short-season vegetable crop like lettuce after early-planted bok choy.
• For later dates, work under any harvest remains to avoid insect or pathogen buildup, and plant a cover crop. In the northern United States and Canada, you can follow summer- and early-fall-harvested bok choy with a cover crop of oats and peas in September, or rye and vetch planted at later dates. Adjust accordingly in other regions.

Harvest, Bok Choy and Chinese Cabbage

---

Ready-to-harvest and quality indicators

• Bok choy and joi choi heads are 8–12 inches tall and 2–3 lbs. each, depending on the variety.
• Mei qing choi heads are harvested at about 1 lb. each.
• Heads are free from damaged or yellow leaves.

Harvest and cleaning procedures

• Harvest in the morning to avoid field heat accumulation.
• Wash hands and sanitize knives before harvesting.
• Use different boxes in the field than the ones you use for distribution.
• Slide the knife under the head and cut it off where the root meets the stem. Be careful to leave the head intact.
• When you cut properly and straight, the bottom of the head is nice and smooth.
• If the lower leaves are damaged or yellow, cut just above the lower leaves to leave them on the ground. Re-trim if your first cut did not leave behind a nice, smooth surface on the bottom.
• It’s important to cut at the correct place so that all the excess leaves fall off. Stripping off leaves after cutting is incorrect. Cut a second time if you need to remove leaves.
• One person cuts the heads and another person counts and packs them.

Washing and storage procedures

• Wash hands and rinse boots before entering the wash-and-pack shed, and cover up field clothes with a bib. If a long-sleeve shirt contains soil, remove this as well.
• Wash this crop only once, preferable with a hose (use potable water). If dunking is necessary to remove field heat or dirt, use the second dunking to hydrocool the product by adding ice to the water or having it pre-cooled.
• Add a sanitizer to wash water if dunking. Use the guide How to Wash Produce Using a Peracetic Acid Solution to establish how much hydrogen peroxide and peracetic acid solution to add to water.
• Leave the heads in water until the core of the stems are properly cooled down.
• Pack them in sealed boxes to avoid having the product lose moisture during longer storage.

Additional resources

• Production Guide for Storage of Organic Fruits and Vegetables

Packing and storage summary for bok choy

Cleaning in the field	Remove dead and yellow leaves.
Packing in the field	12 heads per 1 ¾-bushel box
Packing for delivery	20 lbs. in 1 ¾-bushel boxes (for medium-sized heads) See the International Federation for Produce Standards for the correct PLU code. Add the prefix 9 for organic crops. Pack in any clean box of choice for CSA distribution or the farmers market
Storage	At 32°–41° and 95–100% humidity. Pack in closed containers or bags for storage that lasts longer than 5 days. Chinese cabbages are sensitive to ethylene exposure. Long-term exposure will turn green leaves yellow. Allow for good air exchange and don’t store with crops that release ethylene.

This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture through the Sustainable Agriculture Research and Education (SARE) program. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.