Skip to content.

Some features of this website require Javascript to be enabled for best usibility. Please enable Javascript to run.

Français

Ministry of Agriculture, Food and Rural Affairs

shanghai pak choy

Other Common Names Include:

Bok Choy, Shanghai Choy Sum, Chingensai

Latin Name: Brassica rapa subsp. chinenesis var. communis

Plant Family: Brassicaceae

Close Relatives: Bok Choy

Uses and Markets: Culinary (used in Asian cuisine e.g. edible leaves and stalks used in soups and stir-fries).  Pak Choy is a non-heading cabbage and is a green petiole version of Bok Choy.  The “Shanghai” type of Pak Choy is a lighter green colour than regular Pak Choy.

Shanghai Pak Choy seedling emerging from soil (Photo credit: Sean Westerveld, University of Guelph)Field grown Shanghai pak choy (Photo credit: Sean Westerveld, University of Guelph)
Agronomics
Production Life Cycle in Ontario

Annual

Hardiness Zone

N/A

Special Notes

Brassica crops are cool-season vegetables. They perform best at moderate temperatures and can withstand mild frosts.  Low temperatures early in the growing season may cause premature seedstalk development (bolting).  Extreme changes in temperature, poor soil conditions or low nutrient levels also induce bolting.  Shanghai Pak Choy is also sensitive to daylength and will bolt if exposed to long-day photoperiods, although bolting is not often a problem under Ontario conditions. 

Propagation method

Most commonly by direct seed, less commonly by transplants.

Greenhouse Seeding/Propagation Dates

March-April

Field Seeding Date:

April to August

Field Transplanting Dates

April to August approximately 4 weeks after seeding.

In-row spacing

15 cm

Between row spacing

45 cm

Optimal Soil temperature at planting

>5°C

Fertility

No current Ontario fertility recommendations exist. Research and recommendations from outside Ontario do not necessarily apply to Ontario growing conditions. Experience from Ontario field trials suggests that Shanghai Pak Choy requires 90-120 kg N/ha for each planting through the growing season.   Click here for phosphorus and potassium application guidelines and for more information on specialty crop fertility.

Soil type

All soil types with good drainage, growing best in muck soils.

Soil pH

6.0-7.5

Special requirements for growth habit

None

Optimal Temperature Range

15-18°C

Temperature sensitivity

Frost tolerant.

Irrigation requirements

Irrigation required under normal Ontario conditions.

Days to harvest

45-60

Specialized equipment

None

Harvest
Harvest Scheduling

Multiple harvests from the same planting; Successive plantings.  Multi-cropping possible.

Hand harvest or machine harvest

Hand harvest

Quality parameters/grades

No established grades. Quality is determined by the market.

Additional Harvest Notes

Harvest during cooler parts of the day to reduce moisture loss and cooling costs. Remove field heat as soon as possible after harvest.

Post harvest
Special handling/curing

None

Storage Conditions

Relative humidity (RH): 95-100 %

Temperature:  0°C

Air Exchange: N/A

Duration: 2-3 weeks

Pests
Specific pests observed on this crop in Ontario (observations based on limited experience with this crop)

Insects and Invertebrates: Cabbage maggot (Delia radicum), flea beetles, swede midge (Contarinia nasturtii), diamondback moth larvae (Plutella xylostella), imported cabbage worm (Artogeia rapae), cabbage looper (Trichoplusia ni), tarnished plant bug (Lygus lineolaris), cutworms, aphids, seedcorn maggot (Delia platura)

Diseases: Cabbage maggot (Delia radicum), flea beetles, swede midge (Contarinia nasturtii), diamondback moth larvae (Plutella xylostella), imported cabbage worm (Artogeia rapae), cabbage looper (Trichoplusia ni), tarnished plant bug (Lygus lineolaris), cutworms, leafminers (Liriomyza spp.), aphids

Other: None

Other Potential Pests: The following pests have not been observed on this crop in Ontario. However, they are either significant concerns for closely related plants in Ontario, or are reported on this crop in other production areas. This is not a comprehensive list of all potential pests. Not all of these pests will necessarily survive Ontario’s climate, but could potentially survive in a protected environment (e.g. greenhouse, storage facility).

Insects and Invertebrates: Earwigs, slugs, thrips, seedcorn maggot (Delia platura)

Diseases: Bacterial leaf spot (Pseudomonas syringae), black rot (Xanthomonas campestris), damping off (Pythium, Rhizoctonia spp.), Fusarium wilt (cabbage yellows)

Other: None

*Indicates pests commonly mentioned as causing significant damage or economic loss to this crop in other regions.

Comments

To date the following pests have been the most significant in Ontario: flea beetles, clubroot, downy mildew.  Flea beetles tend to prefer specialty crops (e.g. Chinese cabbage, bok choy, daikon) over traditional brassica crops.  Club root damage will be less when grown during cooler times of the year (e.g. April and Aug/Sept. plantings).  Many specialty Brassica crops are included in Crop Group 5:  Brassica (Cole) Leafy Vegetables.   A complete list of all crops included in Crop Group 5 can be found on Health Canada’s website .  For more information on Crop Groups, refer to the Pest section.  Always refer to product labels, and follow all directions specified on the label, before applying any pest control product.  For more information, consult an OMAFRA specialist. For pest control products registered on Brassicas, refer to OMAFRA Publication 838, Vegetable Crop Protection Guide.  For more information on pests of Brassica crops, refer to the Brassica module of Ontario CropIPM on the OMAFRA website.

Downy mildew on specialty brassicaFlea beetle and damage on specialty brassicaDiamond back moth on specialty brassicaImported cabbageworm and damage on specialty brassicaAlternaria on specialty brassicaSpecialty brassica showing symptoms of severe clubroot on the roots (Photo credit: Thomas Gludovacz, University of Guelph) Swede midge larvae on brassica plantSwede midge damage to broccoliCabbage maggot on brassicaCabbage looper larvae
Additional Notes

Due to problems with various diseases and pests, a rotation period of 3 to 4 years without any Brassica crops is recommended.

Ontario Research Projects Used to Create This Profile
  1. Loughton, A. et al.  1986.  Vegetable Cultivar Trials 1986.  Horticultural Experiment Station Simcoe, Ontario Ministry of Agriculture and Food, unpublished.
  2. McDonald, M. R., Janse, S., and K. Vander Kooi.  1999.  Muck Vegetable Cultivar Trial & Research Report 1999.  Department of Plant Agriculture, University of Guelph, unpublished.
  3. McDonald, M. R., Janse, S., and K. Vander Kooi.  2000.  Muck Vegetable Cultivar Trial & Research Report 2000.  Department of Plant Agriculture, University of Guelph, unpublished.
  4. McDonald, M. R., Janse, S., and K. Vander Kooi.  2001.  Muck Vegetable Cultivar Trial & Research Report 2001.  Department of Plant Agriculture, University of Guelph, unpublished.
  5. McDonald, M. R., Janse, S., and K. Vander Kooi.  2002.  Muck Vegetable Cultivar Trial & Research Report 2002.  Department of Plant Agriculture, University of Guelph, unpublished.
  6. Mcdonald, M.R., Kornatowska, B., and McKeown, A.W. 2004. Management of Clubroot of Asian Brassica Crops Grown on Organic Soils. ACTA Horticulture, 635:25-30.
  7. McDonald, M. R., Janse, S., and K. Vander Kooi.  2005.  Muck Vegetable Cultivar Trial & Research Report 2005.  Department of Plant Agriculture, University of Guelph, unpublished.
  8. McDonald, M. R., Janse, S., and K. Vander Kooi.  2008.  Muck Vegetable Cultivar Trial & Research Report 2008.  Department of Plant Agriculture, University of Guelph, unpublished.
  9. McDonald, M. R., Janse, S., and K. Vander Kooi.  2009.  Muck Vegetable Cultivar Trial & Research Report 2009.  Department of Plant Agriculture, University of Guelph, unpublished.
  10. McDonald, M. R., Janse, S., Riches, L., Tesfaendrais, M., and K. Vander Kooi.  2010.  Muck Vegetable Cultivar Trial & Research Report 2010.  Department of Plant Agriculture, University of Guelph, unpublished.
  11. Westerveld, S. M., Bakker, C. J., and A. W. McKeown.  2007.  Vegetable and Non-traditional Crops Research Report 2007.  Department of Plant Agriculture, University of Guelph, unpublished.
References
  1. Allen, J., Fraser, H. and R. Hallett.  2008.  The Swede Midge – A Pest of Crucifer Crops.  Factsheet 08-007, Ontario Ministry of Agriculture, Food and Rural Affairs. Queen’s Printer for Ontario. 
  2. Chaput, J. 1998. Asian Vegetables Grown in Ontario, Factsheet 98-033, Ontario Ministry of Agriculture, Food and Rural Affairs. Queen’s Printer for Ontario. 
  3. Chaput, J. and R. Cerkauskas. 2000. Insects, Diseases and Disorders of Asian Vegetables, Factsheet 00-095, Ontario Ministry of Agriculture, Food and Rural Affairs.  Queen’s Printer for Ontario.
  4. Chuang, Hsue-Yu., Tsao, Shing-Jy., Lin, Jaw-Neng., Chen, Kan-Shu., Liou, Tsung-Dao., and Chung, Mei-Chu. 2004. Genetic Diversity and relationship of non-heading Chinese cabbage in Taiwan. Botanical Bulletin of Academica Sinica, 45:331-337.
  5. Gossen, B.D, K.K.c. Adhikari, and M.R. McDonald. 2011. Temperature influences development of clubroot under controlled conditions. Plant Pathol. 60. Early view on line publication Doi: 10.1111/j.1365-3059.2011.02536.x.
  6. Hill, David E. 1990. Chinese cabbage and Pak Choi trials 1988-89. Connecticut Agricultural Experiment station, New Haven.
  7. McDonald, M.R, and S.M. Westerveld. 2008. Temperature prior to harvest influences the incidence and severity of clubroot on two Asian brassica vegetables. HortScience 43:1509-1513.
  8. Munro, D. B., and E. Small.  1997.  Vegetables of Canada.  NRC Research Press, Ottawa.
  9. Ontario Agricultural Value-Added Innovation Network. 2002. Alternative Agriculture.  Brantford.