When to Plant Grass Seed in Alberta
Alberta’s first frost comes in September, so the fall seeding window closes in August. Spring is a real option here, not just a fallback.
When to plant grass seed in Alberta is early August for a fall seeding, or late spring once the soil has warmed. Calgary and Edmonton reach their first fall frost in September, so the six-week deadline lands in August.
The University of Saskatchewan, writing for Prairie lawns, calls both spring and late summer to early fall good seeding times. In Alberta, spring often wins, because August is hot and dry.
Alberta grass seeding at a glance: Calgary, Edmonton and Medicine Hat: by about August 10–12. Red Deer: by early August. Lethbridge: a little later, mid-August. Spring: once the soil is above 10°C, with daytime highs near 15°C. Without irrigation, time seeding for when rain is forecast.
Seeding somewhere else in Canada? See When to Plant Grass Seed in Canada for every region in one table.
Alberta Grass Seeding Dates by City
| City | Zone | Avg last spring frost | Avg first fall frost | Fall: seed by |
|---|---|---|---|---|
| Medicine Hat | 4b | May 15 | Sep 22 | Aug 11 |
| Lethbridge | 4b | May 14 | Sep 27 | Aug 16 |
| Calgary | 3b | May 23 | Sep 21 | Aug 10 |
| Red Deer | 3b | May 19 | Sep 13 | Aug 2 |
| Edmonton | 4a | May 14 | Sep 23 | Aug 12 |
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.
Spring or August?
August seeding gives grass a cool fall to root in, but it means watering through the hottest weeks. Spring seeding gives a full season of growth before winter, but the grass meets summer heat young. On the Prairies either can work. If you cannot water through August, choose spring.
For small repairs, the University of Saskatchewan prefers spring, so weeds do not move into bare spots first.
Dry-Land Lawns
For lawns that will not be watered, the University of Saskatchewan suggests sowing seed more thickly and timing the sowing for when rain is expected. It recommends Canada No. 1 grass seed, since cheaper blends may carry more weed seed.
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 cold-climate mixes, see grass seed for cold climates. For the rest of the year, see the lawn care calendar.
Further east: when to plant grass seed in Quebec · in Atlantic Canada.
Frequently Asked Questions
When should I plant grass seed in Alberta?
By about August 10 to 12 for a fall seeding in Calgary and Edmonton, or in late spring once the soil is above 10°C.
When should I plant grass seed in Calgary?
By about August 10, six weeks before Calgary's late-September first frost, or in late spring.
When should I plant grass seed in Edmonton?
By about August 12, or in late spring once daytime temperatures are about 15°C.
Is spring or fall better for grass seed in Alberta?
Both can work on the Prairies. Spring suits lawns you cannot water through a hot August; fall suits lawns you can.
How do I seed a lawn I will not water?
Sow more seed than usual and time it for when rain is expected, as the University of Saskatchewan suggests.
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.
Sources
- University of Saskatchewan, Gardening at USask — Lawns
- Environment and Climate Change Canada — Canadian Climate Normals (the frost dates in the tables, read from this site’s frost data)