How late is too late to seed canola?

Factors in this decision are maturity of the variety, average date of first fall frost, crop insurance deadlines and profit potential of alternative crops.

Maturity of the variety. Ask for the days to maturity of the variety you plan to seed. Note that maturity differences between varieties narrow as you get into warmer climates, such as southern Manitoba, and as you seed later into May and June. Total days required to mature a variety also go down with later seeding. For example, a variety rated at 100 days to maturity may only take 95 days to mature if seeded the end of May. That’s because the plant has more rapid accumulation of heat units in those warmer days. Seeding in June could perhaps knock 5-10 days off posted maturity.

Average date of first fall frost. This will tell you how much growing season you have left — on average. Fall frost risk is a key factor in determining crop insurance seeding deadlines. Click your province for a map showing average dates for first fall frost: Alberta Saskatchewan Manitoba. (Click here for frost probabilities for each station on Alberta’s AgroClimatic Information Service (ACIS) website.) Most fall frosts occur within two weeks either side of the average date for your area. For example, if the first fall frost is between August 31 and September 6, on average, then a variety with 100 days to maturity should be seeded this week to be on the lower risk side for fall frost losses. Deeper dive: One consideration is that fall frosts have been getting later and that long-term averages may not reflect recent trends. Growers in Alberta can try to verify these changes.

Profit potential of other crops. Yield potential for all crops drops with late seeding. Will a lower-yielding canola crop provide a better return than a lower-yielding wheat or barley crop? Take time to pencil out the economics. Also consider quality. Grade (particularly green seed) is often a bigger issue than yield for later canola crops.

Crop insurance deadlines. ALBERTA: AFSC in Alberta has extended its recommended seeding date deadlines for yield and quality coverage to June 5 for Argentine canola and June 15 for Polish canola. The original deadline was May 31. Yield-only insurance deadline is still June 20. Read more. SASKATCHEWAN: For seeding deadlines in Saskatchewan contact your local SCIC office. Find office contacts and more information here. MANITOBA: Seeding deadlines for Manitoba are June 15 for Argentine canola in risk area 1, June 10 for Argentine canola in risk area 2 and June 20 for Polish. Read more.

Further reading:

Late seeding? Tips to help canola mature faster
Alberta Agriculture data on canola yield by seeding date