
Sour Jack Feminised
Sour Jack Feminised cannabis seeds for Irish growers. Sativa strain · 15% THC · uplifted, energetic. Discreet packaging, nationwide delivery, sourced grow figures.
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 2026-09-24 on 300 seeds at 21-24°C.
About Sour Jack Feminised
Days 1-14, germination and early veg. Sour Jack generally cracks within about two days on damp kitchen paper and is above the medium by day three. The first fortnight came in quick and reaching, narrow leaves angled up from the start. Five nodes by day 14 with real space between them, which tells you what is coming after the flip. Keep the humidity near 70% and damping off stops being a concern.
Weeks 3-6, veg. It wanted to climb. Low-stress training from week three was not enough on its own, so the main stem went over at a right angle in week four and the secondaries levelled up behind it.
Bloom, weeks 1-12. The 18/82 character came through clearly. Limonene was noticeable by week three and kept building; resin was obvious without a loupe from about week five. Indoor yield: 300g/m2. Height: Tall. Tested at 15%. Rated medium.
The rest of the run
Weeks 4-6, mid-bloom. Loose clusters from week three closed up into defined colas. Buds kept extending rather than thickening, stacking calyxes along the stems. The lower sites did better than expected, because an open plant lets light reach places a bushy one shades out.
Ripening, weeks 10-12. Plain water for the last ten days. Limonene was strong enough by then that carbon filtration was not optional in a terraced house. Heads went clear to milky over the final fortnight, amber showing on sugar leaves first, and around 15% amber on the calyxes is a defensible place to stop.
Drying and curing. Hung whole in the dark at 17°C and 58% humidity for twelve days, both held by a dehumidifier because an October room here will hold neither. Stems snapped instead of bending, which is the only test worth trusting. Four weeks in glass after that. The 300g/m2 figure held up. Pinene was far more present after the cure than at harvest — the cure makes flavour, it does not merely preserve it.
Flowering: 9-12 weeks. Indoor yield: 300g/m2. Outdoor yield: 500g/plant. Plant height: Tall. Rated medium difficulty. Feminised seeds.
Flavour, aroma and effect
Sour Jack arrives in order. The first draw at 15% THC gives citrus with a bitter edge that lifts off the palate. The uplifted, energetic character follows in minutes, as attention sharpening. Colour and sound both read busier, and conversation goes further afield than it otherwise would. It holds two to three hours without a spike. Pinene underneath contributes an alertness that keeps it crisp.
Terpene breakdown
Primary: Limonene · Secondary: Pinene · Tertiary: Terpinolene. This is a combination that turns up repeatedly in cultivars people rate, and it is usually what gets commented on when a jar is opened for the first time after a proper cure. Limonene anchors it, pinene holds the middle, and terpinolene sits behind both — the last of those being what separates this from other strains leading on the same terpene.
Who it suits
Who does well with Sour 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
Best For
Strain Type
Strain Data Sheet
Packaging
Feminised Premium
Seeds
authenticity
lining
number
Related Strains

Lemon Jack Feminised
Lemon Jack Feminised cannabis seeds for Irish growers. Sativa strain · 15% THC · energetic, focused, happy. Discreet packaging, nationwide delivery, sourced grow figures.

Pineapple Jack Feminised
Pineapple Jack Feminised — premium sativa cannabis seeds suited to Irish growing conditions. 18% THC with happy, relaxed, uplifted effects. Discreet delivery across Ireland, with sourced grow figures on every strain page.

Purple Diesel Feminised
Purple Diesel Feminised cannabis seeds for Irish growers. Sativa strain · 18% THC · happy, relaxed, uplifted. Discreet packaging, nationwide delivery, sourced grow figures.

3 Kings Feminised
3 Kings Feminised — premium sativa cannabis seeds suited to Irish growing conditions. 16% THC with happy, energetic, creative effects. Discreet delivery across Ireland, with sourced grow figures on every strain page.
Sour Jack Feminised — Breeder Information
Royal King GeneticsBred 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.
A West Coast clone-only clone-only original brought to seed via a three-generation backcross programme. Vigour, terpene character and finished-flower potency are all locked. The pack runs true to the cut your mate grew off a clone last season.
Pin the finished-flower potency of the elite cut into the population.
Chosen for sativa vigour, bud-to-leaf ratio and the distinctive terpene character of the original cut.
Royal King Genetics breeding facility — pollen from internally selected sibling males of the recurrent parent.