Frost dates are averages, not guarantees. The "last spring frost" is the date after which frost is unlikely in a typical year — but a cold snap can still happen a week or two later, so keep row cover handy.

Why both dates matter

The gap between your last spring frost and first fall frost is your frost-free period — the length of your growing season. In much of the Prairies that's about 100 days; on the southern coast it can exceed 200. Choose varieties whose days-to-maturity fit comfortably inside that window.

Play it safe

  • Harden off transplants for a week before setting them out.
  • Watch the local forecast, not just the calendar, around your frost dates.
  • Low spots and clear, still nights frost first — site tender crops accordingly.

See your city's exact frost dates by selecting it on the homepage.