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Ministry of Agriculture, Food and Rural Affairs

flowering edible rape

Other Common Names Include:

Yu Choy, Yow Choy, You Cai, Aburana, Cai Ngot, Yuchaeip

Latin Name: Brassica rapa subsp. chinensis var. oleifera

Plant Family: Brassicaceae

Close Relatives: Broccoli, cabbage, kohlrabi

Uses and Markets: Culinary (used predominantly in Asian cuisine e.g. leaves are steamed or boiled for use  in soups and stews or stir fried). 

Field production of flowering edible rape (Photo credit: Sean Westerveld and Cathy Bakker, University of Guelph)Flowering edible rape harvested and boxed for distribution (Photo credit: Mary Ruth Mcdonald, University of Guelph)
Production Life Cycle in Ontario


Hardiness Zone


Special Notes

Brassica crops are cool-season vegetables. They perform best at moderate temperatures and can withstand mild frosts.

Propagation method

Most commonly by direct seeding, less commonly by transplants from seeds.

Greenhouse Seeding/Propagation Dates:


Field Seeding Date:

Mid April to mid September.

Field Transplanting Dates

Late April to mid September.

In-row spacing

5-10 cm

Between row spacing

30-45 cm

Optimal Soil temperature at planting



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 Flowering Edible Rape requires 80-120 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, growing best in sandy loam soils.

Soil pH

5.5-7.5, lower pH may cause the prevalence of clubroot to increase.

Special requirements for growth habit


Optimal Temperature Range


Temperature sensitivity

Frost tolerant.

Irrigation requirements

Irrigation is beneficial under normal Ontario conditions.

Days to harvest

50-55 days after direct seeding.

Specialized equipment


Harvest Scheduling

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 when the lowest (most mature) buds are unopened, or starting to open into flowers, depending on the target market. 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


Storage Conditions

Relative humidity (RH):

Temperature:  0°C

Air Exchange: N/A

Duration: 10-14 days

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

Insects and Invertebrates: Flea beetles, cabbage maggot (Delia radicum), swede midge (Contarinia nasturtii), diamondback moth larvae (Plutella xylostella), imported cabbage worm (Artogeia rapae), cabbage looper (Trichoplusia ni), cutworms, leafminers (Liriomyza spp.), aphids

Diseases: Club root (Plasmidiophora brassicae), downy mildew (Peronospora parasitica), Alternaria leaf spot, turnip mosaic virus (TuMV), baceterial soft rots (Erwinia cartovera, Pseudomonas spp.)

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, tarnished plant bug (Lygus lineolaris) , 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.


To date the following pests have been the most significant in Ontario: flea beetles, club root, 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).  Flowering edible rape is less susceptible to clubroot than some other Brassica vegetables, such as Shanghai pak choy, but is not resistant to the disease.

 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 at the following link 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 this crop group 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


Ontario Research Projects Used to Create This Profile
  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. Westerveld, S. M., Bakker, C. J., and A. W. McKeown, A.W.  2007.  Vegetable and Non-traditional Crops Research Report 2007.  Department of Plant Agriculture, University of Guelph, unpublished.
  1. Adhikari, Kalpana, M.R. McDonald, and B.D. Gossen. 2012. Reaction to Plasmidiophora brassicae Pathotype 6 in Lines of Brassica Vegetables, Wisconsin Fast Plants, and Canola. HortScience. 47(3):374-377.
  2. 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.   
  3. Chaput, J. 1998. Asian Vegetables Grown in Ontario, Factsheet 98-033, Ontario Ministry of Agriculture, Food and Rural Affairs. Queen’s Printer for Ontario. 
  4. 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.  
  5. Kader, A. A. 1993.  Postharvest Handling, p. 353-377. In: Preece, J.E. and Read, P.E., The Biology of Horticulture- An Introductory Textbook. John Wiley & Sons, New York.
  6. Larkcom, J. 2007. Oriental Vegetables. Pan Macmillan Limited, London.
  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 43:1509-1513Munro, D. B., and E. Small.  1997.  Vegetables of Canada.  NRC Research Press, Ottawa.
  8. Ontario Agricultural Value-Added Innovation Network. 2002. Alternative Agriculture.  Brantford.
  9. Ontario Ministry of Agriculture, Food and Rural Affairs.  2010.  Publication 363 Vegetable Production Recommendations 2010-2011.  Queen’s Printer for Ontario, Toronto.
  10. Stephens, J. M. 1994.  Broccoli, Chinese - Brassica alboglabra L. Publication HS565, IFAS Extension, University of Florida. 
  11. University of California Division of Agriculture and Natural Resources.  1998.  Publication 3346 Specialty and Minor Crops Handbook, Second Edition.  University of California, Oakland.
  12. World Crops for the Northeastern United States. 2004. Yu Choi.