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The Official Cannabis collection · sheet 10No 10 · Critical Jackvs Jack Herer

Comparison

Critical Jack vs Jack Herer

Jack Herer is Critical Jack’s father, a Sensi Seeds sativa hybrid from the mid-1990s; Dinafem crossed it with its faster-flowering Critical+, and Leafly users give both strains the same two leading effects, focused and energetic.1,2,3,4 In state labs Jack Herer tests higher: 19.59% median THC across 910 tests, against 15.01% for Critical Jack from only eight tests, a small sample.5

Side by side

Critical JackJack Herer
TypeSativa-leaning hybrid; Dinafem lists 60% sativa / 40% indica2,4Sativa-dominant hybrid (55% sativa per Leafly; 50/50 per Sensi Seeds)1,6
LineageCritical+ × Jack Herer (Dinafem Seeds, Spain)2,7Haze hybrid × Northern Lights #5 × Shiva Skunk (Sensi Seeds, Netherlands)1
Median THC (state lab tests)15.01% (only eight tests, a small sample)19.59% (910 tests)
Middle half of THC results13.41%–20.68%17.13%–22.00%
Top terpenes (median)Too few tests for a profile (1 of 8 with terpene values)Terpinolene, β-Caryophyllene, α-Humulene (413 tests)
Leafly top effectsFocused, energetic, uplifted4Focused, energetic, creative1
FlavorPine, citrus, lemon4Pine, woody, earthy1
Flowering60 days indoors (Dinafem’s spec)250–70 days per Leafly; 10–12 weeks per Sensi Seeds1,6

Lab rows come from the same state lab dataset and matching rules for both strains.5

Lab-tested THC: Critical Jack vs Jack Herer

12% 14% 16% 18% 20% 22% Jack Herer Jack Herer: median 19.59%, middle half 17.13%–22.00%, 910 tests 19.6% n=910 Critical Jack Critical Jack: median 15.01%, middle half 13.41%–20.68%, 8 tests 15.0% n=8 Median total THC (dot) and middle half of tests (bar)
Median and middle half of total THC in state lab tests. Small sample: Critical Jack has only 8 tests.5

Why the cross exists

Silent Seeds, which sells the Dinafem line today, sums up the idea as "Critical+’s fast and profuse flowering and Jack Herer’s vigour and Haze character"; Dinafem’s Critical+ finishes in 45–50 days against Jack Herer’s 10–12 weeks in Sensi Seeds’ own description.3,6,8 Delicious Seeds made the same move with Critical Mass and called the result Critical Jack Herer, which is why Leafly lists that name as an alias of Critical Jack.4,9

More comparisons

Sources

  1. Leafly, Jack Herer strain information. Accessed Oct 3, 2026.
  2. Dinafem Seeds, Critical Jack: feminized seeds, specifications, lab analysis and awards. Accessed Oct 3, 2026.
  3. SeedFinder, Critical Jack (Silent Seeds): strain info. Accessed Oct 3, 2026.
  4. Leafly, Critical Jack aka Critical Jack Herer strain information. Accessed Oct 3, 2026.
  5. Cannlytics (CC BY 4.0), cannabis_results: public state lab results (filtered and aggregated by Official Cannabis). Accessed Oct 3, 2026.
  6. Sensi Seeds, Jack Herer regular seeds. Accessed Oct 3, 2026.
  7. Weedmaps, Critical Jack strain page. Accessed Oct 3, 2026.
  8. Dinafem Seeds, Critical+ feminized seeds. Accessed Oct 3, 2026.
  9. Delicious Seeds, Critical Jack Herer feminized seeds. Accessed Oct 3, 2026.