Sir Jack by Exotic Seeds
1 other breeder's version of Sir Jack — compare flowering times side by side →
Everybody knows Jack Herer, but Exotic Seed took that legendary lineage and completely dialed it in for the modern era with Sir Jack. Around the year 2000, they hunted through a massive pool of Jack genetics and found a specific, unicorn phenotype that stood head and shoulders above the rest. Instead of muddying the waters with an outcross, they took that elite female clone and self-pollinated her to create an S1 generation. The result? A stabilized, feminized version that captures everything we love about the old-school Jack but cranks the reliability up to eleven. Growers who remember the early days of hunting through unstable sativa packs instantly recognized this as a godsend.
In the garden, Sir Jack demands respect. She’s a 70% sativa-dominant beast that will stretch hard if you don't keep her canopy in check. Old heads recommend aggressive training and scrogging early on to manage her height, otherwise she'll easily outgrow your lights. But the payoff is ridiculous. By the time you hit late flower, the room absolutely reeks of that classic, sharp lemon-incense aroma. It's a complex, piercing smell that instantly takes you back to the early 2000s Amsterdam coffee shop scene. The buds stack up chunky and heavy, coated in a greasy layer of resin that makes trimming a total scissor-hash nightmare in the best way possible.
The high is exactly what you want from a proper Jack selection—pure, soaring cerebral energy. It hits right behind the eyes and keeps you functional, creative, and buzzing for hours. Exotic Seed didn't stop there, either. They eventually took this stabilized S1 and crossed it with Auto Skunk to drop Sir Jack Auto, giving outdoor guys and closet growers a way to pull that heavy lemon-incense fire in just 12 weeks from seed. But whether you're running the auto or the photoperiod, finding that heavy incense pheno is the ticket. When you get it dialed in, there’s nothing else quite like it in the stash jar.
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Similar strains
| Breeder | Exotic Seeds |
|---|---|
| Type | mostly sativa |
| Flowering time | ±63 days |
| Environment | Outdoors |
| Lineage | Jack Herer |
| Descendants | Sir Jack Auto, Devil Kush, Exotic Colours, Sir Jack Auto, Exotic Colours, Devil Kush |
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🧬 Explore the family: Jack Herer · Sir Jack Auto · Devil Kush · Exotic Colours · Sir Jack Auto · Exotic Colours · Devil Kush
Ancestry Pedigree
Sensi Seeds
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Unknown or Legendary
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Growing Sir Jack: what to expect
As a sativa-leaning plant, plan for a big stretch after the flip (often 100–200%) — flip earlier than feels natural and keep training options ready. Sativa-leaning plants also generally prefer a lighter feed than heavy indicas. Growers familiar with Jack Herer will recognize much of its behavior. Whatever the listing says, the cut in YOUR tent is the ground truth: log feedings, readings, and photos, and let the trends — not the label — drive decisions.
Sir Jack FAQ
How long does Sir Jack take to flower?
Sir Jack typically flowers in around 63 days after switching to a 12/12 light schedule. Individual phenotypes vary, so judge harvest readiness by trichome color, not the calendar.
Is Sir Jack an indica or a sativa?
Sir Jack is listed as mostly sativa.
What are the parents of Sir Jack?
Sir Jack was bred from Jack Herer by Exotic Seeds.
What environment does Sir Jack like?
Standard cannabis bands work well: VPD 0.8–1.1 kPa in veg and 1.0–1.4 kPa in flower, with humidity stepping down from 65–75% as a seedling to 40–50% in late flower. See the stage-by-stage table on this page.
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