Canola Grower FAQs

Canola input costs can be similar to, or higher than wheat depending on several factors. Nitrogen and sulfur requirements and seed costs are typically higher, while herbicide and insecticide costs can be lower or higher than wheat. Seed costs are lower for winter canola than spring canola, and can vary by whether the seed is open-pollinated or hybrid, and conventional vs herbicide tolerant. Herbicide costs can be less for canola than wheat depending on the resistance trait(s). Canola may also require insecticide applications when pest thresholds are reached.

Canola typically requires more nitrogen than wheat. Current recommendations for the PNW are 7 pounds of nitrogen per 100 pounds of expected canola yield, including nitrogen already available in the soil before seeding. Soil testing is important because residual nitrogen can significantly affect fertilizer needs. PNW-specific fertility research and publications are available in the Research Library.

Sulfur is especially important, and a nitrogen-to-sulfur ratio of 7:1 is recommended when both N and S are deficient. Canola also uses phosphorus, potassium, and micronutrients such as boron. Because nutrient availability varies by soil type, rainfall, rotation, and field history, routine soil testing is the best way to determine what a specific field needs. Additional fertility guidance is available on the Production Strategies page.

Fertilizer placement is important because canola seed is sensitive to fertilizer injury. Fertilizer should not be placed directly with the seed. A separation of at least one inch, and preferably two inches, between seed and fertilizer is recommended. Growers should review PNW-specific fertilizer management resources in the Research Library before finalizing fertility plans.

Knowing the herbicide history of a field is critical when planning to grow canola as canola is particularly sensitive to Group 2 herbicides. Select spring or winter canola varieties with Group 2 herbicide tolerance if those products have been applied in previous years. In-season weed control options include labeled grass herbicides for all varieties, and specific broadleaf herbicides in herbicide-tolerant varieties such as glyphosate for glyphosate-tolerant canola, and glufosinate for glufosinate-tolerant canola. Growers should always follow current labels and review the herbicide plant-back information on the Production Strategies page.

Winter and spring canola can be produced with as little as 10–12 inches of available water, including growing-season precipitation and stored soil water. Yield potential increases with higher water availability and adequate fertility. Irrigated canola may require roughly 11–18 inches of supplemental irrigation, depending on rainfall, soil type, and evapotranspiration. Regional production guidance is available on the Production Strategies page.

Canola emergence through crusted soil depends on crust thickness, seed depth, soil uniformity, and moisture beneath the surface. If the soil is uniform from the seed to the surface, canola seedlings may push through successfully. If the soil is soft below a hard crust, cotyledons may follow the path of least resistance instead of breaking through. A coil packer or similar tool may help break crust with minimal soil disturbance when timed correctly.

Commercial canola fields do not require managed pollination because canola is primarily self-pollinated. However, studies have shown pollinators such as honey bees and native bees can shorten the flowering period and improve yield. Canola is a valuable forage source for bees during bloom, and beekeepers often collaborate with growers to place hives near canola fields. Canola can also be a valuable forage source for bees during bloom. When insecticide applications are needed, growers should coordinate with nearby beekeepers and follow pollinator protection best practices. Pollinator resources are available in the Research Library and through the Honey Bee Health Coalition.

Canola pest and disease pressure in the Pacific Northwest varies by region, season, rotation, and field history. Common insect pests include cabbage aphid, cabbage seedpod weevil, flea beetle, and diamondback moth. Regular scouting is important because populations can change quickly and treatment decisions depend on timing and thresholds. Diseases such as blackleg, Rhizoctonia, and sclerotinia have been observed in some areas, although disease pressure has generally been limited by environment, rotation intervals, and seed treatments. Pest and disease management resources are available in the Research Library.

Winter canola can be managed as a dual-purpose crop in some systems. It is seeded in early summer, grazed or harvested for forage or silage in late summer or early fall, allowed to regrow before winter, and then harvested for grain the following summer. Dual-purpose canola requires careful planning around planting date, grazing timing, stand recovery, and winter survival. Research and production resources are available in the Research Library.