Français Outdoor growers in Quebec work with a short season. In much of the province, cold, wet weather arrives between late September and mid-October, and a plant that is still flowering then is at risk of mould and a lost harvest. The most useful thing to know about any strain is when it actually finishes outdoors here, and how it copes with a damp fall.
This list answers that with grower reports rather than seed-pack numbers. We went through 236 reviews left on our strain pages between 2017 and 2026, by growers in Quebec, Ontario, Nova Scotia, British Columbia, Alberta and the northern United States, and kept only the strains with real outdoor reports. They are listed from the earliest finisher to the latest. Where growers disagreed, we say so.
A note on the numbers in this article: harvest dates, flowering times and yields are ranges, not promises. They vary depending on growing conditions: the grower, the method and the season's weather. "Mold resistant" means mold tolerant: less prone to mold and slower to be affected. No strain is 100% mold resistant. How we set these numbers →
Quick comparison
| Strain | Outdoor finish reported by growers | Mould reports (clean / problems) | Outdoor reports |
|---|---|---|---|
| M 39 Granddaddy | Early September (one plant not done October 21) | 0 / 0 | 2 |
| Quebec Early Bud | Mid-September; later at 49° latitude | 2 / 0 | 5 |
| God Kush | September 22 to mid-October | 1 / 0 | 2 |
| Cinderella 99 | September 20 to October 19 | 1 / 0 | 2 |
| Black Runtz | Third week of September to late October | 1 / 0 | 2 |
| Quebec White | Last week of September to first week of October | 5 / 0 | 8 |
| Lemon Kush | Early October | 2 / 0 | 3 |
| Quebec Black Gold | Late September to mid-October, varies by plant | 2 / 0 | 13 |
| Grape Skunk | Early to late October | 6 / 1 | 10 |
| Animal Gelato | Mid-October | 1 / 1 | 7 |
| Quebec Blue | Second week of October to early November | 9 / 6 | 21 |
“Clean” means the grower said the plant had no mould, mildew or bud rot. “Problems” means they reported some. Reports with no comment either way are not counted in those two columns.
The strains, from earliest to latest
1. M 39 Granddaddy
The fastest finisher in our reports. A Northern Ontario grower harvested in early September 2023 and called it the fastest-flowering plant he had grown. The original M 39, which this line comes from, finished mid-September outdoors for a grower who had grown it twenty years earlier.
Where to be careful: one 2020 report was not ready on October 21 and the grower doubted it would finish before the freeze. Start it on time and do not count on every plant finishing in September.
2. Quebec Early Bud
Two growers confirmed the mid-September finish, in 2023 and 2024, and one of them harvested “as promised” and called it extremely mould resistant. Another 2024 report had no mould, rot or mildew after storms and a frost.
Where to be careful: two 2025 reports disagreed. A grower at 49.5° latitude in Ontario still had a month to go on September 26, and a grower in New York State had several weeks to go in mid-September. Further north, or in a cold summer, plan for late September rather than mid.
3. God Kush
A grower in Virginia harvested on September 22, 2025 and described it as very resistant to mould, pests and mildew. An Ontario grower took about 500 g from one plant by mid-October 2024. Only two outdoor reports so far, both positive.
4. Cinderella 99
One grower harvested on September 20, 2024. In Cape Breton, Nova Scotia, another picked on October 19, 2025 with no pest or fungal issues at all, in one of the dampest climates in the country. A good choice if you want a sativa effect without a November harvest.
5. Black Runtz
One grower took 17 oz from a plant by the third week of September 2024. Another, in early 2025, called it very resistant with no mould or bud rot, but a slow finisher that was not ready on October 20.
Where to be careful: two reports, two very different finish dates. Treat it as a late September to late October strain depending on your plant and your season.
6. Quebec White
The best-documented strain on this list, with eight outdoor reports and not one mould problem. One grower harvested on September 29, 2024 and wrote that his Quebec Whites got no white powdery mildew while the other strains around them did. Others finished in the last week of September and the first week of October, one of them with 800 g and no mould or mildew. Five reports specifically praised its mould resistance.
Where to be careful: one 2022 grower harvested in the first week of November with a low yield. If a plant is late, it is late; do not wait on it in a wet fall.
7. Lemon Kush
Three reports, all five stars. A BC grower who was worried about mould found it “really resistant” on a 7-foot plant. An indoor grower saw it resist powdery mildew while a plant in the same tent had it. Outdoors, a 2024 grower was still a few weeks out in late September, so plan for early October.
8. Quebec Black Gold
Our most-reviewed early strain, with thirteen reports, and the one where honesty matters most. Growers who had it finish in September said our dates were accurate (2023), and one 2020 grower rated its mould resistance A+ after it stayed clean while the skunks beside it got mildew. In 2025 a grower at 49.5° latitude harvested on October 18 and called the mould resistance really good.
Where to be careful: finish dates vary from plant to plant. Growers reported October 1, the second week of October and October 18, and one in Southern Ontario found the flowering times inconsistent, with the late plants not finishing. Two plants, in 2019 and 2020, never formed buds before frost. Expect late September to mid-October, not September, and start seeds early.
9. Grape Skunk
Ten reports, and one of the strongest mould records we have. A Southern Ontario grower cut on October 2, 2025 with no insects, powdery mould or mildew. Earlier growers called its resistance to powdery mildew outdoors excellent (2022), and another dried it beside a mouldy batch without it catching anything (2024). It grows very tall, very fast; one plant reached 11 feet.
Where to be careful: that 11-foot plant had minor powdery mildew, and two growers reported low yields. One harvested as late as October 30. Yield and finish both depend heavily on how it is grown.
10. Animal Gelato
An Ontario grower in 2024 said it matured about ten days earlier than his Jack Herer and Blue Dream, untouched by powdery mildew and clear of bud rot. Another harvested in mid-October 2023 and lost only about 15 g to rot.
Where to be careful: a Nova Scotia grower had minimal yield outdoors from April to the end of October and found indoor clones did better. It is a mid-October strain and rewards a warm season.
11. Quebec Blue
Our most-grown outdoor strain, with 21 reports, and the one that needs the plainest description. Harvests came in on October 8, the second week of October, mid-October and, for one patient grower, early November with close to a kilo. Nine growers reported no mould or rot, including one on the Pacific coast, one in rainy, foggy Nova Scotia, and one who lost 25% to mould while the strains next to it lost 80%.
Where to be careful: six growers did report powdery mildew or some rot, and one called it weak against mildew. Quebec Blue holds up better than most in a wet fall, but it is a mid-October finisher and it is not immune. Give it air, keep an eye on the leaves in late summer, and harvest when it is ready rather than when the calendar says.
Bred for the north, waiting on your reports
Three of our strains were bred for a September finish but do not yet have outdoor harvest reports from growers: Quebec Gold Express, Critical Fast Version and Northern Lights Fast Version. We have left them off the ranked list until growers confirm the dates. If you have grown one of them outdoors, a review on the strain page is the most useful thing you can give the next grower.
Three things the reports agree on
Start early. Almost every late or unfinished plant in these reports was started late or force-flowered too late. Start seeds indoors in April and move them out after the last frost.
Airflow beats genetics. The growers with the cleanest plants, on every strain, mentioned spacing, air movement and harvesting on time. The growers with mould on “resistant” strains usually had dense buds in a wet October.
Read the plant, not the pack. The same strain finished three weeks apart for growers in the same province. Check trichomes from mid-September and be ready to harvest early if the weather turns.
Frequently asked questions
Which outdoor strains finish earliest?
The guide lists M 39 Granddaddy and Quebec Early Bud first, from earliest to latest.
How many strains are compared?
Eleven, in a quick comparison table covering outdoor finish and mould reports from growers.
Are the finish dates guaranteed?
No. They come from grower reports and vary with season, site and method.
Is any strain fully mould proof?
No strain is 100% mould resistant; good airflow and site choice still matter.
