Critical Jack cannabis seeds packaging — Royal King Seeds Ireland
Hybrid
THC 20%
🎨 Creative
HybridFeminisedIn Stock

Critical Jack Feminised

Critical Jack Feminised cannabis seeds for Irish growers. Hybrid strain · 20% THC · focused, relaxed, uplifted. Discreet packaging, nationwide delivery, sourced grow figures.

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Royal King Genetics — first-party test batch

Figures below are from our internal seed-lot QC and verified Irish grower submissions, not breeder marketing. Determined from a single batch tested 2026-09-08 on 100 seeds at 21-24°C.

Germination rate: 97.4% (n=100)
Last QC test date: 2026-09-08
Indoor yield: 409-580 g/m² (avg across 9 verified grower reports)
Outdoor yield, Ireland: 461-670 g/plant (avg across 8 verified grower reports)

About Critical Jack Feminised

Does Critical Jack finish outdoors in Ireland? It does, planted out at the end of May and cut by early October. The 50/50 balance handles an Irish season without special treatment, which is most of the reason to choose it. Bloom takes 60 days, so the harvest date is set by the calendar far more than by your technique.

What should I expect to take off it? 625 g/m2 indoors and 1200 g/plant outdoors are the published figures, and both assume a full light or a full season plus a root run to match. A tunnel gets you most of the way to the outdoor number; a windowsill will not. At 20% THC the effort is well spent either way.

Is it a sensible first grow? Reasonably. Anyone who has finished one grow will manage this one; it asks for consistency rather than expertise.

Other questions that come up about Critical Jack

Soil or coco? Coco with fertigation at EC 1.4-1.8 through bloom if you are there daily and want speed. Peat-free soil with slow amendments — fish, blood and bone, seaweed meal, rock phosphate — if you are not, and want flavour. Both suit this hybrid; the deciding factor is your week, not the plant.

How does it handle the weather here? Hybrid vigour covers most of what an Irish summer does. Keep the root zone under 28°C and do not transplant into a warm spell.

When does bloom feed start? Within a week of the first pistils. The 50/50 balance shifts demand quickly at the transition — phosphorus and potassium up, nitrogen down. Soil growers top-dress; coco and hydro switch formula immediately.

Tunnel, outdoors or indoors? A tunnel is the best value of the three here. Indoors you own the 60 days of bloom completely; outdoors the plant gets light no lamp matches and can reach 1200 g/plant, and pays for it in rain. Flowering: 60 days. Indoor yield: 625 g/m2. Outdoor yield: 1200 g/plant. Plant height: Medium. Rated medium difficulty.

Flavour, aroma and effect

Critical Jack arrives in order. The first draw at 20% THC gives citrus with a bitter edge that lifts off the palate. The focused, relaxed, uplifted character follows in minutes, as head and body together. Thinking stays clear while the muscles let go by degrees, which is what makes the dose, rather than the genetics, the thing that decides the evening. Caryophyllene underneath contributes warmth that keeps it anchored.

Terpene breakdown

Primary: Limonene · Secondary: Caryophyllene · Tertiary: Linalool. Temperature decides how much of this profile survives. Low vaporisation at 180-188°C keeps caryophyllene and linalool audible over the limonene; run it hotter, or burn it, and all three collapse into one note that is pleasant enough and tells you nothing.

Who it suits

Who does well with Critical Jack? Indoor growers who want to choose their own timeline. Tunnel growers who want to decide when flowering starts rather than letting August decide it. Anyone with the space to veg it properly first. Rated medium, which means a moderate learning curve that rewards attention without needing specialist kit.

Effects

🧠Focused
76% of people reported feeling Focused
😌Relaxed
65% of people reported feeling Relaxed
😎Uplifted
58% of people reported feeling Uplifted
😊Happy
51% of people reported feeling Happy
🤩Creative
50% of people reported feeling Creative
🤗Euphoric
40% of people reported feeling Euphoric
🤤Hungry
34% of people reported feeling Hungry
😴Sleepy
31% of people reported feeling Sleepy
😆Giggly
24% of people reported feeling Giggly

Best For

✦ Daytime
✦ Depression
✦ Fatigue
✦ Stress

Strain Type

Indica 50%Sativa 50%

Strain Data Sheet

🧬THC20% - 25% (High)
🌿LineageCritical Plus × Jack Herer
🔬TypeFeminised Hybrid
🌡ClimateTemperate, adaptable
📅HarvestSept – Nov, S. hemisphere (typical)
📏HeightMedium
⚖️YieldHigh
🏠Yield Indoor625 g/m2
🌳Yield Outdoor1200 g/plant
⏱Flowering Time60 days

Packaging

Resealable +
RK
Royal King Seeds
Photoperiod
Feminised Premium
Seeds
Premium Genetics
Protective vial
Resealable +
Royal King Seeds supplies seeds as adult novelty collectibles and for genetic preservation. Purchasers are responsible for complying with the law where they live.
1
Critical Jack Feminised
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💧Waterproof coating
🛡️Aluminium interior lining
🏷️Protective sticker
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🔢Scratchable serial number

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Critical Jack Feminised — Breeder Information

Royal King Genetics

Bred and stabilised in-house by Royal King Genetics — our internal breeding team. Every batch is QC'd and germ-tested above 99% before it ships. Read the full breeding process and about page.

Stabilisation Level
F5 IBL
Generations
5+
Breeding Programme
Inbred Line (IBL) — multi-generation inbred selection
Stabilisation Notes — What This Means for Your Grow

Five generations of inbred selection on the original early-2000s legacy Critical Jack cuts. We were not chasing a redesign — we locked the pack-to-pack uniformity that earned this cultivar its reputation. Whatever the next pack throws is what the last pack threw.

Breeding Goal

Restabilise a early-2000s legacy cultivar to contemporary uniformity standards.

Selection Focus

Chosen for terpene profile, vigour, structure and finish-time consistency.

Pollen / Mother Source

Royal King Genetics select-mother programme — pollen drawn from an internally maintained reversed-female line.

Last Batch QC Verified
9 September 2026· 99%+ germination