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Ministry of Agriculture, Food and Rural Affairs


Other Common Names Include:


Latin Name: Cannabis sativa L. subsp. sativa

Plant Family: Cannabaceae

Close Relatives: Marijuana (C. sativa L. subsp. indica), hops

Uses and Markets: Industrial (fibre, textile, biocomposites, paper, fuel); culinary (grain and oil); personal care products.

A hemp field in Ontario A hemp plant Hemp grain Self seeded stand of hemp

Late season stand of hemp

Production Life Cycle in Ontario


Hardiness Zone


Special Notes

Different cultivars are grown for fibre or seed. Industrial hemp is a controlled substance and may only be grown under licence from Health Canada.   Only varieties named in the “List of Approved Cultivars”, published by Health Canada, are approved for planting in Canada.  Information about varieties, licences and regulations may be obtained on Health Canada’s website or by contacting Health Canada’s  Office of Controlled Substances at: Tel. (613) 954-6524 E-mail:

Propagation method


Greenhouse Seeding/Propagation Dates


Field Seeding Date:

Mid-spring.  Early planting produces taller plants with higher fibre yields.

Field Transplanting Dates


Seeding/ Planting rate - Plant Density
Fibre: 200-250 plants/m2, grain: 100-150 plants/m2.

Between row spacing

15-18 cm

Optimal Soil temperature at planting

>6-10°C at a soil depth of 3 cm.


No current Ontario fertility recommendations exist. Research and recommendations from outside Ontario do not necessarily apply to Ontario growing conditions. Hemp requires approximately the same fertility as a high-yielding crop of wheat. Research is continuing to define the exact nutrient requirements. Apply up to 110 kg/ha of nitrogen, depending on soil fertility and past cropping history. Click here for phosphorus and potassium application guidelines and for more information on specialty crop fertility.

Soil type

Well drained soils. Avoid extremely heavy or light soils.

Soil pH


Special requirements for growth habit

Small seeded crops require good seed to soil contact and finely prepared seedbeds.

Optimal Temperature Range

25-28 °C

Temperature sensitivity

Frost tolerant; seedlings are frost sensitive.

Irrigation requirements

Grain hemp requires significant water (125 to 175 mm) during flowering and seed set. While beneficial, irrigation is not normally used in hemp production.

Days to harvest

Depends on end use. Textile fibre: harvest at flowering approximately 70-90 days after seeding; Industrial fibre: harvest any time after flowering. Grain: harvest when approximately 70% of the seed is ripe (22-30% moisture content), 100-120 days after seeding.

Specialized equipment


Harvest Scheduling

Single harvest

Hand harvest or machine harvest

Machine harvest; Standard field-crop equipment including sickle mowers, haybines, round balers and combines.

Quality parameters/grades:

No established grades. Quality is determined by the market.

Additional Harvest Notes


Post harvest
Special handling/curing

Retting to separate the bast fibres from the hurds or other plant tissues is usually done in the field.  For storage, stalk moisture should be less than 15% at time of baling, and should continue to dry to about 10%.  Grain hemp should be dried to 12 % moisture for storage.

Storage Conditions

Relative humidity (RH): Store in a cool/dry environment.

Temperature: Any temperature (fibre); Cool temperatures will extend storage life (grain).

Air Exchange: N/A

Duration: Indefinitely (fibre); 1 or more years under good storage conditions (grain).

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

Insects and Invertebrates: European corn borer* (Ostrinia nubilalis), grasshoppers (Melanoplus spp.)

Diseases: White mold/hemp canker* (Sclerotinia sclerotiorum) botrytis head blight* (Botrytis spp.), , damping off/root rot (Fusarium, Pythium)

Other: Birds*

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: Stem borers (e.g. Ostrinia nubilalis*, Grapholita delineana*), cutworms, slugs, white grubs, mites, caterpillar defoliators

Diseases: Gray mold *(Botrytis cinerea), root knot nematodes (e.g. Meloidogyne incognita, M. hapla)

Other: Parasitic plants attacking roots - broom rape* (Orobanche ramose)

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


More than 50 different viruses, bacteria, fungi and insect pests are known to affect the hemp crop. However, hemp's rapid growth rate and vigorous nature allow it to overcome the attack of most diseases and pests. Bird damage has been severe in some areas of Ontario and Manitoba. Significant losses in grain yields up to the entire crop have been reported. Crop rotation would appear to be a good cultural practice to avoid disease build-up until more is known about hemp's susceptibility to disease organisms. A 4-year rotation is recommended. Do not grow hemp on the same fields following canola, edible beans, soybeans or sunflowers. There are few to no pest control products registered on this crop in Ontario.

Additional Notes

Police checks must be completed for a commercial licence to grow hemp and must be renewed annually. Licensing is done by the Industrial Hemp Regulations and the Therapeutic Products Directorate of Health Canada.

Click here for a more comprehensive production guide.

Ontario Research Projects Used to Create This Profile

  1. Asbil, W, L. Bell, and L. MacGregor.  2008. Assessments of agronomic methods to improve the processing quality of hemp grown for fiber in eastern Ontario. Kemptville College, University of Guelph
  2. Baillie, C . 2004. Development of plant fibre composites for structural applications. OMAFRA - New Directions Program
  3. Baker, J. 2006. Biofibre genetic profiling and breeding program. OMAFRA - New Directions program
  4. Ontario hemp alliance. 2008. Hemp breeding and national hemp grain variety characterization/ development project
  5. Ontario Hemp Alliance. 2009. Canadian Hemp Industry Review Project (CHIRP). AAFC- ACAAF funding.
  6. Sain, M. 2003. Bioconversion of Ontario agricultural fibre crops. OMAFRA- New Directions Program
  7. Scheifele, G.  1999. Determining the feasibility and potential of field production of low THC industrial hemp (Cannabis sativa) for fibre and seed grain in northern Ontario.  OMAFRA/University of Guelph Program. 
  8. Thamae, TM. 2008. Developing and characterizing new materials based on natural fibres and waste plastic. Graduate Research, Queens University. x
  1. Agriculture and Agri-FoodCanada. 1994. Bi-weekly Bulletin. Volume 7 (23). Agriculture and Agri-FoodCanada.
  2. Baxter, B. and G. Scheifele. 2000. Growing Industrial Hemp in Ontario. Ontario Ministry of Agriculture, Food and Rural Affairs.
  3. Clarke, R. 1999. Botany of the Genus Cannabis, pp. 1-18. In: P. Ranalli (ed.). Advances in Hemp Research. The Haworth Press, BinghamptonNY.
  4. Hanks, A.  Canadian Hemp: A Plant with Opportunity. Agriculture and Agri-foodCanada. Canada Hemp Trade Alliance.
  5. McPartland, J. 1999. A Survey on Hemp Diseases and Pests, pp. 109-132. In: P. Ranalli (ed.). Advances in Hemp Research. The Haworth Press, BinghamptonNY.
  6. McPartland, J., R. Clarke and D. Watson.  2000.  Hemp Diseases and Pests: Management and Biological Control.  CABI Publishing, Oxfordshire UK.
  7. Robinson, B. 1935. Hemp. United States Department of Agriculture