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The Official Cannabis collection · sheet 10No 10 · Critical JackGenetics

Genetics

Critical Jack genetics: Critical+ × Jack Herer

Critical Jack is a cross of Critical+, Dinafem’s Big Bud × Skunk that finishes in 45–50 days indoors, with Jack Herer, the Sensi Seeds sativa hybrid from the Netherlands.1,2,3 Dinafem says the cross carries Skunk #1, Northern Lights and Haze genetics, and sources agree on the parents but not on where Critical+ itself came from.4,5

Family tree

  • Critical+ (Dinafem)Big Bud × Skunk per Dinafem; released 2005; a Critical Mass selection per SeedFinder
  • Jack Herer (Sensi Seeds)Haze hybrid × Northern Lights #5 × Shiva Skunk; Netherlands, mid-1990s

Critical Jack

  • Pai GowSuper Silver Haze × Critical Jack
  • Baccarat (Symbiotic Genetics)Bred from Critical Jack (SeedFinder)
  • Birrie Jack (Amaranta Seeds)Bred from Critical Jack (SeedFinder)
  • Killer Critical Jack (MadCat’s Backyard Stash)Bred from Critical Jack (SeedFinder)
  • Critical Jack (Fatbush Seeds)Bred from Critical Jack (SeedFinder)
  • Critical Jack Autoflowering (Growers Choice)Bred from Critical Jack (SeedFinder)
Parents as stated by Dinafem; offspring as listed by Leafly and SeedFinder.1,6,7

The two parents

Critical+ is Dinafem’s own strain: "created by crossing Big Bud x Skunk", released in 2005, slightly indica-dominant, finishing in 45–50 days indoors with a strong lemon scent.2 Leafly gives the same parents, credits Dinafem Seeds and says it "won the first Highlife Cup in Barcelona".8

Jack Herer is Sensi Seeds’ sativa-dominant hybrid, created in the Netherlands in the mid-1990s from a Haze hybrid, Northern Lights #5 and Shiva Skunk, named after the activist and author of The Emperor Wears No Clothes and, Leafly says, distributed by Dutch pharmacies as a recognized medical-grade strain.3 Sensi Seeds itself calls the line 50% sativa and 50% indica and says it is one of the few strains sold in pharmacies in the Netherlands.9 Weedmaps says Dinafem pollinated its Critical+ with a Jack Herer male from Sensi Seeds.10

Where Critical+ comes from: two accounts

Sources agree that Critical Jack is Critical+ × Jack Herer, but the Critical side has two origin stories, and one database swaps in a different Critical altogether.

AccountWho says so
Critical+ = Big Bud × Skunk, bred by DinafemDinafem; Leafly2,8
Critical+ is a selection (S1) descending through Critical Bilbo from Critical Mass, Mr. Nice’s Afghani × Skunk #1SeedFinder’s genealogy; Leafly’s Critical Mass page for the Mr. Nice parentage7,11
Critical Jack = Jack Herer × Critical MassAllBud12
Critical Jack Herer = Critical Mass × Jack Herer (a different, Valencia-bred cross that shares most of the name; SeedFinder writes its mother as Critical Bilbo)Delicious Seeds; SeedFinder13,14

How sativa is it?

Mostly, by label. Dinafem’s genotype field says 40% indica / 60% sativa, Silent Seeds repeats it, AllBud calls it a 60% sativa-dominant hybrid and Wikileaf a 55% sativa hybrid; Leafly and Weedmaps file it as a hybrid without a split.1,10,12,15,16,17 SeedFinder classes it indica/sativa and its growers report two phenotypes, one sativa-dominant, long and stretched, the other indica-dominant, short and compact.5 Delicious Seeds’ Critical Jack Herer is labelled 80% sativa.13

One name, several seed lines

SeedFinder lists four strains called Critical Jack, from Dinafem, Silent Seeds, Dr. Blaze and Fatbush Seeds.18 Silent Seeds, which describes itself as "the sole heir to DINAFEM SEEDS", publishes the same cross and almost the same specifications as Dinafem, and SeedFinder says its version "was developed using the same clones that created Critical Jack by Dinafem".15,19,20

Two autoflowering lines borrow the name without being bred from Critical Jack. Dinafem’s Critical Jack Autoflowering is "born from the cross between our Critical + 2.0 elite clone and our Haze 2.0 Autoflowering", 60% indica, with 10–15% THC.21 Critical+ 2.0 is Dinafem’s moisture-resistant rework of Critical+.22 Delicious Seeds’ Critical Jack Herer Auto is Critical Mass Auto × Jack Herer Auto.23

What our lab data adds

Little, with only eight tests. Strict name matching found 8 flower tests of plain Critical Jack against 14 results under near-miss names, 12 of them flower, led by "Nature's Critical Jack #3" (10 results) and 3 products labelled "Critical Jack Herer"; 7 results whose strain field and product name disagreed were also left out.24 Leafly’s "Critical Jack Herer" alias and Delicious Seeds’ cross of that name mean a label with "Herer" in it may be either strain.13,17

Strains bred from Critical Jack

StrainCrossSource
Pai GowSuper Silver Haze × Critical Jack; sativa-dominant, terpinolene-led per LeaflyLeafly6
BaccaratBred from Critical Jack (Symbiotic Genetics); other parent not listedSeedFinder7
Birrie JackBred from Critical Jack (Amaranta Seeds); other parent not listedSeedFinder7
Killer Critical JackBred from Critical Jack (MadCat’s Backyard Stash); other parent not listedSeedFinder7
Critical Jack (Fatbush Seeds)Listed by SeedFinder as a descendant of Dinafem’s lineSeedFinder7
Critical Jack Autoflowering (Growers Choice)Listed by SeedFinder as a descendant of Dinafem’s lineSeedFinder7

SeedFinder also files Dinafem’s Critical Jack Automatic under the descendants, but Dinafem’s own page gives its parents as Critical+ 2.0 × Haze 2.0 Autoflowering.7,21

Sources

  1. Dinafem Seeds, Critical Jack: feminized seeds, specifications, lab analysis and awards. Accessed Oct 3, 2026.
  2. Dinafem Seeds, Critical+ feminized seeds. Accessed Oct 3, 2026.
  3. Leafly, Jack Herer strain information. Accessed Oct 3, 2026.
  4. Dinafem Seeds, Critical Jack feminised marijuana strain (Dinafem TV). Accessed Oct 3, 2026.
  5. SeedFinder, Critical Jack (Dinafem): strain info, breeder description and grow reports. Accessed Oct 3, 2026.
  6. Leafly, Pai Gow strain information. Accessed Oct 3, 2026.
  7. SeedFinder, Critical Jack (Dinafem): genealogy and hybrids. Accessed Oct 3, 2026.
  8. Leafly, Critical Plus aka Critical +, Cr+ strain information. Accessed Oct 3, 2026.
  9. Sensi Seeds, Jack Herer regular seeds. Accessed Oct 3, 2026.
  10. Weedmaps, Critical Jack strain page. Accessed Oct 3, 2026.
  11. Leafly, Critical Mass strain information. Accessed Oct 3, 2026.
  12. AllBud, Critical Jack marijuana strain information and reviews. Accessed Oct 3, 2026.
  13. Delicious Seeds, Critical Jack Herer feminized seeds. Accessed Oct 3, 2026.
  14. SeedFinder, Critical Jack Herer (Delicious Seeds): strain info. Accessed Oct 3, 2026.
  15. Silent Seeds, Critical Jack feminized seeds. Accessed Oct 3, 2026.
  16. Wikileaf, Critical Jack strain. Accessed Oct 3, 2026.
  17. Leafly, Critical Jack aka Critical Jack Herer strain information. Accessed Oct 3, 2026.
  18. SeedFinder, All Critical Jack strains. Accessed Oct 3, 2026.
  19. Silent Seeds, Silent Seeds, the sole heir to Dinafem Seeds (home page). Accessed Oct 3, 2026.
  20. SeedFinder, Critical Jack (Silent Seeds): strain info. Accessed Oct 3, 2026.
  21. Dinafem Seeds, Critical Jack Autoflowering. Accessed Oct 3, 2026.
  22. Dinafem Seeds, Critical+ 2.0 feminized seeds. Accessed Oct 3, 2026.
  23. Delicious Seeds, Critical Jack Herer Auto. Accessed Oct 3, 2026.
  24. Cannlytics (CC BY 4.0), cannabis_results: public state lab results (filtered and aggregated by Official Cannabis). Accessed Oct 3, 2026.