Critical Jack by Silent Seeds
2 other breeders' versions of Critical Jack — compare flowering times side by side →
Critical Jack is a sativa-leaning cannabis strain from Silent Seeds, bred by crossing Critical Plus × Jack Herer. Indoors it typically finishes flowering in around 63 days after the flip to 12/12. The environment targets below are the same stage-by-stage bands the Cultivar journal grades real Critical Jack grows against.
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Similar strains
| Breeder | Silent Seeds |
|---|---|
| Type | mostly sativa |
| Flowering time | ±63 days |
| Environment | Outdoors |
| Lineage | Critical Plus × Jack Herer |
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🧬 Explore the family: Critical Plus · Jack Herer
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Growing Critical 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 Critical Plus or 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.
Critical Jack FAQ
How long does Critical Jack take to flower?
Critical 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 Critical Jack an indica or a sativa?
Critical Jack is listed as mostly sativa.
What are the parents of Critical Jack?
Critical Jack was bred from Critical Plus × Jack Herer by Silent Seeds.
What environment does Critical 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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