When to Plant Grass Seed in Quebec
Fall seeding dates for Montreal, Laval, Gatineau, Trois-Rivières, Quebec City and Sherbrooke, counted from each city’s own first frost.
When to plant grass seed in Quebec is mid to late August for most lawns. Around Montreal and Laval you can seed until late August; in Quebec City the deadline is mid-August; in the Eastern Townships it comes in early August.
If the summer slips by, spring is the fallback: once the soil is above 10°C, usually a few weeks after the last frost in May.
Quebec grass seeding at a glance: Montreal, Laval, Gatineau: by late August. Trois-Rivières: by late August. Quebec City: by mid-August. Sherbrooke: by early August. In spring, wait until the soil is above 10°C.
Seeding somewhere else in Canada? See When to Plant Grass Seed in Canada for every region in one table.
Quebec Grass Seeding Dates by City
| City | Zone | Avg last spring frost | Avg first fall frost | Fall: seed by |
|---|---|---|---|---|
| Laval | 5b | Apr 28 | Oct 10 | Aug 29 |
| Montreal | 5b | May 9 | Oct 7 | Aug 26 |
| Gatineau | 5a | Apr 30 | Oct 6 | Aug 25 |
| Trois-Rivières | 4b | May 15 | Oct 5 | Aug 24 |
| Quebec City | 5a | May 17 | Sep 28 | Aug 17 |
| Sherbrooke | 4b | May 28 | Sep 17 | Aug 6 |
The fall dates use this site’s rule for every lawn page: seed at least six weeks before the average first fall frost, so the grass has time to root before winter. The frost dates are Environment and Climate Change Canada normals; every date in the table is counted from them, not typed.
Montreal and the Outaouais: Late August
Montreal, Laval and Gatineau share a first frost in early October, which puts the seeding deadline in the last week of August. Seeding right after an aeration, while the soil is warm and evenings are cooler, gives the best start. See aerating and overseeding by city.
Quebec City and the Eastern Townships: Earlier
Sherbrooke has the earliest average first frost of these six cities, in mid-September, so its seeding deadline comes in early August. Quebec City follows in mid-August. In both, a spring seeding is a sound alternative if you cannot water through August.
Spring Seeding
In spring, the University of Saskatchewan says grass seed germinates best once the soil is above 10°C. Soil lags behind the air, so it suggests waiting for daytime temperatures of about 15°C. That usually means two to four weeks after the last spring frost.
Getting the Seed to Take
Keep the seed moist until it comes up: the University of Saskatchewan says to water daily, or even twice a day, and that new grass takes about two weeks to germinate and be ready to walk on. Press the seed into the soil so it makes good contact; seed sitting on top of thatch rarely takes.
For Quebec mixes, see the best grass seed for Quebec. For the rest of the year, see the lawn care calendar.
Shade
Shaded lawns are the exception to fall seeding. The University of Massachusetts recommends overseeding thin, shaded turf in early to mid spring, as soon as the soil reaches about 10°C, because more light reaches the ground through bare or young tree canopies than in late summer. See grass seed for shade.
Frequently Asked Questions
When should I plant grass seed in Quebec?
Mid to late August for most lawns: late August around Montreal, mid-August in Quebec City, early August in Sherbrooke. Or in spring once the soil is above 10°C.
When should I plant grass seed in Montreal?
By the last week of August, about six weeks before Montreal's early-October first frost.
Is September too late to seed a lawn in Quebec?
For most of the province, yes. Even around Montreal the six-week deadline falls in late August.
Can I plant grass seed in spring instead?
Yes. Seed once the soil is above 10°C, which the University of Saskatchewan says usually means daytime temperatures of about 15°C. Spring-seeded grass needs regular watering through its first summer.
What if I miss the fall deadline?
Wait for spring rather than seeding late into fall. Seed sown too close to freeze-up comes up tender and often does not survive the winter.
How long does grass seed take to come up?
About two weeks, if it is kept moist.
Sources
- University of Saskatchewan, Gardening at USask — Lawns
- University of Massachusetts Amherst Extension — Growing Turf Under Shaded Conditions
- Environment and Climate Change Canada — Canadian Climate Normals (the frost dates in the tables, read from this site’s frost data)