Français Big Jack is an original QCS strain: a fast, heavy-yielding, mostly indica feminized hybrid with 19 to 21% THC, 55 to 60 days of flowering and a mid to late September outdoor harvest. This Big Jack strain review pulls together our own specs, the real reviews on our site and what growers commonly report, so you can decide whether it belongs in your garden.
Big Jack strain at a glance
| Genetics | QCS original (parents not published) |
| Type | Feminized, mostly indica hybrid |
| THC | 19 to 21% |
| Flowering time | 55 to 60 days indoors |
| Outdoor harvest | Mid to late September (mid-October in a cool year) |
| Yield | Up to 800 g/m² indoors, up to 700 g per plant outdoors |
| Outdoor height | 200 to 250 cm |
| Flavour | Citrus, lemon, herbal |
| Growing level | Beginner-friendly |
| Pack | 5 feminized seeds |
| Breeder | Quebec Cannabis Seeds (original QCS genetics) |
What is the Big Jack strain?
Big Jack is an original QCS strain: Quebec Cannabis Seeds is its original breeder, and these are our own genetics, bred in Quebec since 2015 by a grower with more than 35 years of experience.
The Big Jack strain is one of the quickest and most productive plants in the QCS Originals catalogue. QCS describes it as a fast, heavy-yielding, mostly indica hybrid, selected from indica-dominant genetics, with a lemon-led aroma and a balanced, manageable effect. It carries a "harvest from September" badge on our product page, and it is one of our Featured Strains.
We keep the exact parentage private, so you will not find a long lineage string here. The name suggests a Jack-style plant, and growers who know the family often expect vigorous growth and a citrus-herbal profile, but treat that as a hint rather than a fact. What matters for the buyer is that the plant is a QCS original and has been selected for speed, vigour and yield.
A caution when you search around: other seed companies sell a Big Jack of their own, and their genetics, flowering times and numbers can be quite different. Other seed companies' versions may differ; the figures on this page are for the QCS version only.
Is Big Jack indica or sativa?
Big Jack is a mostly indica hybrid. QCS does not publish an exact percentage. In practice, that means a plant that flowers fast, builds fluffy, well-spaced colas and delivers an effect that is strong but balanced rather than sedating.
Do not take "indica" to mean "small", though. Outdoors, the plant can reach 200 to 250 cm, and one reviewer who let a plant go grew it to about 8 feet. If you want to understand the typical indica experience, read our guide to what indica does to you.
Smell and flavour
Big Jack is all about citrus and herbal notes. QCS describes a sweet, lemon-dominant fragrance that gets stronger when you break the buds apart, with a mild herbal background. Many consumers enjoy lemony strains for exactly this reason: the smell is bright and clean rather than heavy and skunky.
The practical good news is discretion. Reviewers describe the plant as relatively discreet in the grow, and one wrote that the smell was low-key. That is not the same as odourless, so plan for a carbon filter if you grow close to neighbours, but it is an advantage if you garden in a shared space.
Big Jack effects
QCS describes the effects as strong but balanced: clear-headed at first, followed by body relaxation. Newer users generally find the intensity moderate and manageable. A reviewer who rated the strain gave the buzz 7 out of 10, which suggests a solid, rather than overwhelming, result.
That arc, a clear start and a gradual settling, is something consumers often report from lemon-forward, mostly indica hybrids. Effects vary by person and dose, and nothing here is medical advice. As always, start low and go slow, particularly if you are new to cannabis.
How strong is Big Jack? THC content
QCS lists Big Jack at 19 to 21% THC. CBD is not listed on the product page. That is a moderate-to-strong range, which makes this a friendly choice for people who want a real effect without chasing the very highest numbers. If you are after higher THC, browse our THC over 25% seeds.
Remember that the final potency depends on how you grow, dry and cure the plant. The number on the page is a guide, not a guarantee.
Growing Big Jack: flowering time and yield
Speed and quantity are the point. Indoors Big Jack flowers in 55 to 60 days and can yield up to 800 g/m², which is high for the QCS catalogue. Outdoors it is usually ready in mid to late September, and a cool year can push it to mid-October. Plants can reach 200 to 250 cm and yield up to 700 g each. These are ranges, not promises.
QCS labels the strain beginner-friendly. It clones easily, vegetates quickly, responds well to topping and netting, and grows what reviewers call "like a weed". The buds are described as fluffy, which helps them dry evenly and resist rot, and reviewers report no mildew or bud rot. Our page reminds buyers that "mold resistant" really means mold tolerant, since no strain is fully mold resistant.
Two practical points. First, it needs full sun and good feeding: height without light and nutrients gives you leaves rather than buds. Second, because it grows so vigorously, train it early. Topping and a net keep the canopy even and make the most of the yield figures above.
What customers report
Big Jack has seven reviews on our site and averages 4.3 out of 5. Here is what they say, including the one unhappy report.
- Easy cloning and fast veg: a grower called it an excellent clone strain that is quick to veg.
- First grow: a first-time grower ran it next to our Quebec Blast, saw no mildew or bud rot on either, found Big Jack buds fluffier and a week slower to flower, and expected harvest from mid-October to the end of October, weather permitting.
- Yield and speed: reviewers wrote "lots of weed, quick to harvest" and "very impressive yield". Another says it "grows like a weed", topped well and made large colas with a discreet smell, scoring yield 10 out of 10, appearance 7 and buzz 7.
- Service: a grower in northern Ontario praised customer service after a germination problem that he attributed to his own method.
- The honest complaint: one grower was not impressed. His plant reached 8 feet but, by his count, produced only about 2 ounces. Big plants without enough light, space or feeding can disappoint, and our page says as much. If a pack of seeds under-performs, contact us: seeds are guaranteed and we will make it right.
Is Big Jack right for you?
Choose Big Jack if you want a quick finish, a high-yield plant and a moderate-to-strong effect with a bright lemon aroma. It suits beginners, outdoor growers who need to be done by late September, and anyone who wants to take clones. It is less suitable if you need a very small plant or a very high-THC strain.
Looking at alternatives? Browse our feminized seeds or our fast version collection. If you want to go much stronger, read our review of Fat Bastard, one of the highest-THC strains we sell.
Why grow Big Jack from Quebec Cannabis Seeds?
- Bred in Quebec by the original breeder. Quebec Cannabis Seeds (QCS) is the original breeder of Big 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.
Big Jack: frequently asked questions
What is the Big Jack strain?
Big Jack is an original QCS feminized hybrid, mostly indica, that is fast to flower and heavy-yielding, with 19 to 21% THC.
Is Big Jack indica or sativa?
It is a mostly indica hybrid selected from indica-dominant genetics. QCS does not publish an exact percentage.
How strong is Big Jack?
QCS lists it at 19 to 21% THC, with a strong but balanced effect. Newer users should start low.
How long does Big Jack take to flower?
About 55 to 60 days indoors. Outdoors it is usually ready in mid to late September, and mid-October in a cool year.
How much does Big Jack yield?
Up to 800 g/m² indoors and up to 700 g per plant outdoors. These are ranges, not promises.
Is Big Jack easy to grow?
QCS labels it beginner-friendly. It clones easily, vegetates quickly and responds well to topping and netting, but it needs full sun and good feeding.
What does Big Jack taste and smell like?
Citrus and herbal, with a sweet lemon-dominant aroma that gets stronger when the buds are broken apart.
Where can I buy Big Jack seeds in Canada and the USA?
Directly from Quebec Cannabis Seeds. Orders ship within 24 hours Monday to Friday in plain packaging, 3 to 7 days in Canada (2 to 3 with Express) and 1 to 2 business days to the USA with Express. Shipping is free over $200, with an 80% germination guarantee and free seeds with every order.
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.
