Français M 39 is an original QCS strain: a feminized, indica-type cross of Skunk No.1 and Northern Lights lineage (F2), listed at 18.5% THC and a very quick 39 to 43 days of flowering. This M 39 strain review covers the QCS specs, what 15 customer reviews tell us and what growers commonly say about this old-school, fast and discreet plant.
M 39 strain at a glance
| Genetics | Skunk No.1 and Northern Lights lineage (F2) |
| Type | Feminized, indica |
| THC | 18.5% |
| Flowering time | 39 to 43 days indoors |
| Outdoor harvest | Early to mid-October |
| Yield | 350 to 450 g indoors, about 500 g outdoors |
| Flavour | Old-school, classic skunk-style |
| Growing level | Easy to grow |
| Pack | 5 feminized seeds |
| Breeder | Quebec Cannabis Seeds (original QCS genetics) |
What is the M 39 strain?
M 39 is an original QCS strain: Quebec Cannabis Seeds presents it as its own genetics, bred in Quebec by a grower with more than 35 years of experience.
M 39 is a feminized indica-type strain built on Skunk No.1 and Northern Lights lineage, two of the most influential names in the history of modern cannabis. Skunk No.1 gave growers speed, vigour and a pungent character; Northern Lights added resin, compact structure and a calm, heavy finish. Put them together and you get a plant that stays low, branches well and finishes remarkably quickly.
The QCS version is an F2, which matters to experienced growers. With an F2 you can see some variation between seeds, and the product page notes that Skunk, Northern Lights and M-39 phenotypes can all show up. That makes it a good option if you enjoy pheno-hunting and picking the plant you like best for your next run.
A word on history: the M-39 name has been around for years and is linked to older, now-retired seed catalogues, so you may find other descriptions online. The figures on this page are for the QCS version only, and other versions may differ.
Is M 39 indica or sativa?
QCS lists M 39 as an indica and does not publish an exact percentage. Its behaviour in the garden fits: low and discreet, bushy side branching and a short flowering time are all typical of indica-leaning plants. The Skunk and Northern Lights parents are both usually described as indica-dominant or hybrid, so the label is consistent with the lineage.
If you want to know what to expect from this side of the family, our guide to what indica does to you is a good place to start.
M 39 smell and flavour
QCS describes an old-school flavour, and that is a fair way to read the lineage. Skunk-family plants are commonly described as pungent, earthy and a little sweet, while Northern Lights lines are often described as sweet, spicy and pine-like. Many growers who run this kind of cross report a strong, classic aroma by the end of flowering.
Because the aroma can be noticeable, carbon filtration is worth considering for indoor grows even though the plant itself stays small. As always, what you smell and taste depends on phenotype, curing and drying.
M 39 effects
The QCS page describes a clean high with a relaxing body buzz. Consumers of Skunk and Northern Lights crosses commonly report a calm, settled feeling with a mellow mood, which many people prefer for evenings. Effects vary from person to person.
At 18.5% THC it is moderate by today’s standards, which many people see as an advantage: easier to enjoy without overdoing it. If you are new to cannabis, still start low and go slow.
How strong is M 39? THC content
QCS lists M 39 at 18.5% THC. That is lower than many of the strains in our catalogue, and a good fit for people who want something classic rather than extreme. The page does not list a CBD figure, so we will not guess one. THC always depends on the grow and the cure.
If you would rather go stronger, compare it with our cannabis seeds over 25% THC.
Growing M 39: flowering time and yield
This is where M 39 shines. Indoors it flowers in just 39 to 43 days, roughly six weeks, which is exceptionally quick for a photoperiod plant. Expect 350 to 450 g indoors, and about 500 g outdoors. Outdoors it is ready in early to mid-October.
It grows quickly, branches well and has an easy-to-trim finish. It stays low and discreet, and QCS says it handles short, harsh northern seasons, which is why it has a following in Quebec and Ontario. Since it finishes so early, it is also a sensible choice if autumn frost comes early where you live.
The product page does not state the indoor yield per square metre, only the totals above, so treat them as ranges depending on pot size, training and space. No strain is 100% mold resistant, so keep airflow up in the last weeks.
What customers report
M 39 has 15 reviews on our site and is shown with a five-star rating. The text of the individual reviews was not available to us when writing this page, so rather than paraphrase what we could not read, here is what we can say honestly:
- Popular with repeat growers: a staple in Quebec and Ontario, according to the product page.
- What growers like on paper: speed, an easy trim and a plant that stays low.
- Our commitment: if a pack under-performs, our 80% germination guarantee and delivery guarantee apply.
You can read the full reviews on the product page.
Is M 39 right for you?
Choose M 39 if you want a fast, low, discreet plant with a classic skunky character and a mellow, clean effect, or if you enjoy selecting phenotypes from an F2. It is also a smart pick for short northern seasons.
If you prefer a stronger or fruitier profile, browse our feminized seeds, read our Fat Bastard review for a very high THC option, or see the fast version seeds.
Why grow M 39 from Quebec Cannabis Seeds?
- Bred in Quebec by the original breeder. Quebec Cannabis Seeds (QCS) is the original breeder of M 39, one of our own QCS Originals, bred here since 2015 by a grower with 35+ years of experience.
- Guaranteed. 80% germination guarantee with replacements, and delivery guaranteed. If a pack under-performs, email us and we make it right.
- Free seeds with every order, and free shipping on orders over $200.
- Fast, discreet shipping. Ships from Quebec within 24 hours Monday to Friday in plain, unbranded packaging, to Canada (Canada Post) and to the USA (1–2 business days by Express).
- Real support. Every email answered within 24 hours.
M 39: frequently asked questions
What is the M 39 strain?
M 39 is an original QCS feminized indica built on Skunk No.1 and Northern Lights lineage (F2), listed at 18.5% THC.
Is M 39 indica or sativa?
QCS lists it as an indica. It stays low, branches well and flowers quickly.
How strong is M 39?
QCS lists 18.5% THC, a moderate level that suits a classic, mellow effect.
How long does M 39 take to flower?
Only 39 to 43 days indoors. Outdoors it is ready in early to mid-October. These are ranges, not promises.
How much does M 39 yield?
350 to 450 g indoors and about 500 g outdoors, depending on the grow.
Is M 39 easy to grow?
Yes. It grows quickly, branches well, trims easily and handles short northern seasons. As an F2, some plant-to-plant variation is normal.
What does M 39 taste and smell like?
An old-school, classic profile in the Skunk and Northern Lights tradition.
Where can I buy M 39 seeds in Canada and the USA?
M 39 seeds are sold at Quebec Cannabis Seeds in packs of 5 feminized seeds, shipped from Quebec across Canada and to the USA, with germination and delivery guaranteed.
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. No strain is 100% mold resistant. How we set these numbers →
About this article
Published by the Quebec Cannabis Seeds team. QCS was founded in 2015 by Trent LaPierre, a Quebec breeder with more than 35 years of hands-on growing experience. Genetics we bred ourselves are described from our own breeding work; when a strain comes from another breeder, we say so and credit them. How we work. Last updated: November 6, 2026.
Sources and further reading: Cannabis Act (Justice Laws, Government of Canada) · Cannabis Regulations (SOR/2018-144). Rules on cannabis seeds differ by province and state; check your local regulations before ordering.
