Français If your summer is short and your autumn turns cold and wet early, the strain you choose matters more than almost anything else you do. This page collects the early finishing outdoor strains for Canada that Quebec Cannabis Seeds sells, with what growers really reported: harvest dates, frost, mould and the years it did not work out. Every number below comes from the grower reports in What 400+ Grower Reports Told Us: reviews on our strain pages, harvested GrowDiaries logs and posts from growers on Instagram and X.
Two things to know first. No cannabis strain is frost proof: a hard frost damages any plant, and early finishers simply give you a better chance of harvesting before it arrives. And "mould resistant" means mould tolerant: less prone to mould, never immune. See the full explanation in our guide to strains bred for the North American climate.
Early finishing strains: what growers reported
These are real, dated reports, including the ones that did not finish on time. Where a strain finished a month late at a high latitude, we say so.
| Strain | What growers reported |
|---|---|
| M 39 Granddaddy | Early September in Northern Ontario (2023); one 2020 plant was not done on October 21 |
| Quebec Early Bud | Mid-September, twice (2023, 2024); a month late at 49.5° latitude in 2025 |
| Quebec White | September 29, last week of September, first week of October (2024) |
| God Kush | September 22 in Virginia (2025); mid-October in Ontario (2024) |
| Cinderella 99 | September 20 (2024); October 19 in Cape Breton (2025) |
| Black Runtz | 17 oz by the third week of September (2024); another plant not ready on October 20 |
| Durban Poison | Late September in Ontario (2020); another grower saw finishes spread from October 1 to 31 |
| Quebec CBD 20-1 | Mid-September and late September in Edmonton; one Ontario plant was not ready at the October 30 frost |
Big outdoor harvests in northern Canada
Two GrowDiaries logs from a grower in northern Canada, where hard frosts arrive in mid-October: Hash Bud gave 740 g dry from a single plant, harvested in rounds from October 3 to 16, and the grower called it "super robust against bud rot". Bubble OG gave 690 g dry from an 8-foot plant with 16 colas, taken down on October 24; it fell over in a windstorm and was fine. The grower noted it would ideally have had another two weeks, which is a useful reminder that even good short-season genetics are working against the calendar.
Mould and mildew reports
Early finishing helps you beat the wet weather, but it is worth knowing how each strain behaved in damp conditions. These counts are from reviews on our strain pages, and none were removed:
| Strain | Clean reports | Mould or mildew reports | Total reviews |
|---|---|---|---|
| Quebec White | 5 | 0 | 8 |
| Grape Skunk | 6 | 1 | 10 |
| Quebec Black Gold | 2 | 0 | 13 |
| Quebec Early Bud | 2 | 0 | 5 |
| Quebec Blue | 9 | 6 | 21 |
Reviews that do not mention mould are counted in the total but not in either column. The full 11-strain table is in the grower reports article.
Fast Version strains for the shortest seasons
If your window is tighter still, look at our Fast Version cannabis seeds: photoperiod strains bred for a much shorter flowering phase. Popular early finishers searched by Canadian growers include Early Skunk, Early Hash Skunk, Bay Burger Fast Version and Appalachian Kush Fast Version. Browse the full outdoor cannabis seeds category for other strains suited to cooler climates.
How to give an early finisher the best chance
- Start on time. Germinate and start seedlings indoors in spring so plants go outside strong rather than late.
- Choose the site carefully. A spot with full sun, good airflow and shelter from wind makes the most of a short season and reduces mould risk.
- Watch the forecast in September. Know your first-frost window and have a plan to cover or move plants for a few cold nights.
- Harvest in rounds if needed. Growers in our reports took the ripest colas first and let the rest finish.
Every seed is tested, and every order is guaranteed
All 337 strains are germination-tested at 98 to 100%, with results published by strain on our seed testing page. Delivery is guaranteed at 100% and germination at 80%, and replacements ship the same day or the next day at the latest. Read the Trust & Guarantees page for how to make a claim.
Frequently asked questions
What are the best early finishing outdoor strains for Canada?
In grower reports, Quebec Early Bud, Quebec White and M 39 Granddaddy were harvested from early to late September in Ontario and Alberta, while Hash Bud and Bubble OG produced large harvests in northern Canada before mid to late October. Results depend on latitude, site and weather.
Are QCS strains frost resistant?
No cannabis strain is frost proof. QCS strains are selected to finish before the cold and rain typically arrive, but a hard frost damages any plant. Choosing an early finisher, starting seeds on time and covering plants on cold nights improve your odds.
When do early finishing strains finish outdoors in Canada?
Grower reports range from early to late September in Ontario and Alberta to mid-October in the north. A few plants were not ready until late October, so treat finish dates as ranges, not promises.
Do early finishing strains resist mould?
Early finishing helps you harvest before the wettest weather, and some strains reported few mould problems, but no strain is mould proof. Good airflow and a sunny, sheltered site matter as much as the strain.
What are Fast Version cannabis seeds?
Fast Version seeds are photoperiod strains bred for a much shorter flowering phase, which suits growers with short seasons or cool nights.
Are the seeds germination-tested?
Yes. Every strain QCS sells is germination-tested at 98 to 100%, and germination is guaranteed at 80%. Results are published by strain on the seed testing page.
