Lawn Calendar
First mow, overseed window, last feed, last cut, and snow-mold watch. Computed for your exact place from the 30-year climate record at your nearest station.
Showing Toronto. Search for your own town, or use your location.
Lawn dates for your place, with reminders.
Weekend work window: Check the live forecast and task windows for your place on the Weather page before you head outside.
Lawn dates for major cities
Computed from each city's own station normals. Your town's dates may differ; use the planner above for your exact place.
| City | First mow | Overseed | Last mow | |
|---|---|---|---|---|
| Victoria | BC | April 25 | September 10 - October 8 | October 22 |
| Vancouver | BC | April 20 | September 15 - October 13 | October 27 |
| Kelowna | BC | April 26 | August 3 - August 31 | September 14 |
| Calgary | AB | May 17 | July 22 - August 19 | September 2 |
| Edmonton | AB | May 14 | July 18 - August 15 | August 29 |
| Saskatoon Diefenbaker | SK | May 9 | July 21 - August 18 | September 1 |
| Regina | SK | May 9 | July 18 - August 15 | August 29 |
| Winnipeg Richardson | MB | May 8 | July 28 - August 25 | September 8 |
| Sudbury | ON | May 10 | August 6 - September 3 | September 17 |
| Ottawa Cda | ON | April 30 | August 11 - September 8 | September 22 |
| Toronto Lester B. Pearson | ON | April 30 | August 21 - September 18 | October 2 |
| Windsor | ON | April 20 | September 4 - October 2 | October 16 |
| Montreal/Pierre Elliott Trudeau | QC | April 30 | August 17 - September 14 | September 28 |
| Quebec/Jean Lesage | QC | May 10 | August 9 - September 6 | September 20 |
| Fredericton | NB | May 10 | July 31 - August 28 | September 11 |
| Halifax Stanfield | NS | May 15 | August 23 - September 20 | October 4 |
| Charlottetown | PE | May 20 | August 22 - September 19 | October 3 |
| Whitehorse | YT | June 1 | June 30 - July 28 | August 11 |
| Yellowknife | NT | June 3 | July 24 - August 21 | September 4 |
Method: monthly mean temperature normals anchored mid-month, linear interpolation across 10 C (first mow) and 7 C (growth slowdown). Frost offsets use the station's average first fall frost. Read the full methodology.
Questions, answered plainly
When should I mow my lawn for the first time in spring?
Wait until the soil has warmed enough that grass is actively growing, roughly when the monthly mean temperature crosses 10 C. In Toronto that is mid to late April; in Ottawa or Montreal, late April to early May; in Calgary or Edmonton, early to mid May. Mowing too early on cold, wet soil compacts the root zone.
When should I overseed my lawn in Canada?
Late summer, four to eight weeks before the average first frost. The soil is still warm for fast germination, but nights are cool enough that the new grass hardens off before winter. In Toronto that means mid August to mid September; in Halifax, mid August to early September; in Winnipeg, mid August.
When is the last fertilizer application?
About six weeks before the first frost. Any later and the nitrogen pushes soft, sappy growth that is vulnerable to winter injury. The tool above computes the date from your station normals.
Why is the last mow important for snow mold?
Long grass matting under heavy, wet snow is the main snow-mold habitat. The final cut should be slightly shorter than summer height, but never scalped, and timed before the ground freezes and snow settles.