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Ministry of Agriculture, Food and Rural Affairs


Other Common Names Include:

Field Gromwell, Bastard Alkanet

Latin Name: Lithospermum arvense (syn. Buglossoides arvensis)

Plant Family: Boraginaceae

Close Relatives: Borage

Uses and Markets: Culinary/Medicinal: oil is an excellent source of stearidonic acid which is converted in the body to omega-3 fatty acids.

Corn Gromwell flowers.
Production Life Cycle in Ontario


Hardiness Zone


Special Notes

Little agronomic information is available for this plant.  Corm gromwell is native to Europe and Asia, and is known in North America and Australia as an introduced species.  It is a common weed in arable fields.

Propagation method

Seeds.  Plant at a depth of 2.5cm.

Greenhouse Seeding/Propagation Dates


Field Seeding Date:

Mid to late spring.

Field Transplanting Dates


In-row spacing

Adjust to compensate for germination rate and 1000 seed weight.

Between row spacing


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. Research from other jurisdictions indicates a nitrogen (N) requirement of 50 kg N/ha. Corn gromwell is not related to any traditional crops with established phosphorus (P) and potassium (K) recommendations in Ontario. Start with average requirements for traditional field crops and adjust over time based on on-farm research trials.

Soil type

Medium to light well-drained soils.

Soil pH

Acidic to alkaline, pH 5-8.

Special requirements for growth habit


Optimal Temperature Range


Temperature sensitivity

Frost tolerant.

Irrigation requirements

Irrigation not usually required.

Days to harvest

100 days (estimated).

Specialized equipment


Harvest Scheduling

Single harvest.

Hand harvest or machine harvest

Mechanical harvest.        

Quality parameters/grades

No established grades. Quality is determined by the market.

Additional Harvest Notes

Corn gromwell retains its seed well and can be direct combined.

Post harvest
Special handling/curing


Storage Conditions

Relative humidity (RH): N/A

Temperature: N/A

Air Exchange: N/A

Duration: N/A

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

Unknown – limited to no production of this crop in Ontario to date.

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).

See comments.

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


There is minimal information on the pests that attack this crop. No specific pests have been reported in the available literature. This crop is not in a crop group. For more information on Crop Groups, refer to the Pest section.  There are few to no pest control products registered on this crop. 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.

Additional Notes


Ontario Research Projects Used to Create This Profile
  1. Todd, J. and E. Elford. 2014. Southwestern Ontario industrial crop demonstration trials. Ontario Ministry of Agriculture, Food and Rural Affairs, unpublished.
  1. Abram, M. 2011.  Corn gromwell: a weed no longer: an arable weed could become an omega-3 oil-producing spring crop option.  Crops 12 (4): 4.
  2. Bently, S.  Corn Gromwell. A new oil crop for UK farmers, containing stearidonic acid (SDA), an omega-3 fatty acid from plants with the health benefit of fish oils