Français Double Jack is an original QCS strain: a 50/50 autoflower bred from Jack Herer and Northern Lights #5 and crossed with Ruderalis, listed at 22% THC. This Double Jack strain review covers our specs, the one real customer review so far, and what growers and consumers commonly report about its famous parents.
Double Jack strain at a glance
| Genetics | (Jack Herer × Northern Lights #5) × Ruderalis |
| Type | Autoflower, feminized, 50% indica / 50% sativa |
| THC | 22% |
| Flowering time | 9 to 10 weeks indoors |
| Yield | 350 to 400 g/m² indoors, up to 200 g per plant outdoors |
| Flavour | Earthy, woody, skunk, pine |
| Growing level | Beginner-friendly, compact |
| Pack | 5 feminized autoflowering seeds (10 and 20 also available) |
| Breeder | Quebec Cannabis Seeds (original QCS genetics) |
What is the Double Jack strain?
Double Jack is an original QCS strain: Quebec Cannabis Seeds is its original breeder, and these are our own genetics bred in Quebec.
Double Jack Autoflower takes two legends and puts them in a plant that runs on its own timer. Quebec Cannabis Seeds bred it from Jack Herer and Northern Lights #5, then added Ruderalis so it flowers automatically with no change in light hours. It is feminized and compact, which makes it practical for tents, closets and balconies.
Jack Herer is a famous sativa-leaning line with a piney, spicy character, and Northern Lights is a classic indica known for resin and a relaxing reputation. Seed companies sell many Jack-based autoflowers, and their lineages, THC figures and timings differ, so remember that the numbers here are for the QCS version only.
Is Double Jack indica or sativa?
The answer is both, in equal measure: QCS lists Double Jack at 50% indica and 50% sativa. That fits the parents, with Jack Herer pulling toward the sativa side and Northern Lights toward the indica side. Expect a plant that is neither a stretchy giant nor a squat bush, though autoflowers stay modest in size either way.
If you are weighing the two sides, remember these labels describe plant shape more reliably than they predict the feeling. Our guide to what indica does to you explains what people usually mean by the indica side.
Smell and flavour: earthy, woody, skunk and pine
The QCS taste profile is earthy, woody, skunk and pine, with the product page adding skunky undertones. That is a very recognisable combination. Pine is the classic Jack Herer calling card, while earthy and skunky notes are what many people associate with Northern Lights.
Our one reviewer said the flower tastes very good after only three days of curing, which is a pleasant hint that the profile shows up early. As a rule, a longer, slower cure rounds off the edges and lets the woody and pine notes come forward, so be patient with the jars.
Double Jack effects
QCS describes the effect as ranging from uplifting to deeply relaxing. That matches the general reputation of the parents: consumers often describe Jack Herer as clear and energetic, and Northern Lights as heavy and calming. A 50/50 hybrid will often sit in between, with a bright start and a steadier, easier landing.
As always, effects depend on dose, tolerance and setting. Dry mouth and dry eyes are commonly reported with high-THC flower. If strong cannabis is new to you, start low and go slow.
How strong is Double Jack? THC content
QCS lists Double Jack at 22% THC, a solid mid-to-upper level that sits below the very high figures in our THC over 25% seeds category. It should feel clearly strong to people with limited tolerance, and satisfying rather than extreme to regular users.
The final number in your jar depends on genetics, light, feeding, drying and curing. The product page does not list a CBD figure.
Growing Double Jack: flowering time and yield
As an autoflower, Double Jack does not need a light schedule. Indoors it takes 9 to 10 weeks of flowering and yields 350 to 400 g/m². Outdoors QCS lists up to 200 g per plant but gives no fixed harvest date, so plan your planting around your local frost date and give it a sunny spot.
Growing tips
Sow straight into its final pot, which QCS suggests should be 15 to 20 litres. Keep conditions steady, use gentle low-stress training instead of topping, and feed lightly early on. The heads get dense, so the product page recommends running a fan in the last three weeks to reduce the risk of mould. Our reviewer agreed that resistance is good as long as the airflow is.
Harvest by looking at the trichomes rather than counting days. For the full autoflower method, see our autoflower seeds guide.
What customers report
Double Jack is a newer listing with one review on our site so far: 4 out of 5 stars from April 2025. We would rather be upfront about that than pad the section.
- Big producer: the grower called it a very big producer with enormous heads.
- Mould: they found it resists mould as long as there is enough airflow, in line with the product page.
- Flavour: very good taste after three days of curing.
- Why not five stars? The review does not give a complaint, so we cannot say what cost the missing star. With a single review, treat our specs as your main guide.
Is Double Jack right for you?
Choose Double Jack if you like piney, earthy, skunky flower, want a balanced hybrid effect and prefer an autoflower that is easy to run. It asks a little more patience than the shortest autos, at 9 to 10 weeks of flowering. If you would like something with a different structure, see our autoflower seeds or read our Fat Bastard review if you want to see another QCS original.
Why grow Double Jack from Quebec Cannabis Seeds?
- Bred in Quebec by the original breeder. Quebec Cannabis Seeds (QCS) is the original breeder of Double Jack, 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.
Double Jack: frequently asked questions
What is the Double Jack strain?
Double Jack Autoflower is a QCS original: a feminized 50/50 autoflower bred from Jack Herer and Northern Lights #5 and crossed with Ruderalis, with 22% THC.
Is Double Jack indica or sativa?
It is a balanced hybrid: 50% indica and 50% sativa. Its effects are described as ranging from uplifting to deeply relaxing.
How strong is Double Jack?
QCS lists it at 22% THC, a solid mid-to-upper level. Effects vary by person, so start low and go slow.
How long does Double Jack take to flower?
About 9 to 10 weeks of flowering indoors. These are ranges, not promises.
How much does Double Jack yield?
350 to 400 g/m² indoors and up to 200 g per plant outdoors. Real results depend on your light, pot size and method.
Is Double Jack easy to grow?
Yes. QCS calls it beginner-friendly and easy to grow. It stays compact and suits a 15 to 20 litre balcony pot. Run a fan during the last three weeks to keep the dense heads dry.
What does Double Jack taste and smell like?
Earthy, woody, skunk and pine, with skunky undertones.
Where can I buy Double Jack seeds in Canada and the USA?
Double Jack seeds are sold at Quebec Cannabis Seeds in packs of 5, 10 and 20, shipped from Quebec across Canada and to the USA. Germination (80% guarantee, with replacements) and delivery are 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.
