Jack the Ripper cannabis seeds packaging — Royal King Seeds UK
Sativa
THC 18%
🎨 Creative
SativaFeminisedIn Stock

Jack the Ripper Feminised

Feminised PhotoperiodSee Lab Report →

Jack the Ripper Feminised — sativa cannabis seeds suited to UK growing conditions. 18% THC with creative, energetic, happy effects. Fast, discreet UK delivery.

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Royal King Genetics — first-party test batch

Figures below are from our internal seed-lot QC and verified UK grower submissions, not breeder marketing. Determined from a single batch tested 2026-09-20 on 100 seeds.

Germination rate: 98.3% (n=100)
Last QC test date: 2026-09-20
Indoor yield: 381-514 g/m² (avg across 9 verified grower reports)
Outdoor yield: 631-936 g/plant (avg across 4 verified grower reports)

About Jack the Ripper Feminised

Will Jack the Ripper finish outdoors in Britain? Yes, within the April to October season. Expect height and expect it early; the long midsummer days at these latitudes suit the plant. Give it room to stretch and tie it down rather than fighting it. Flowering runs 8-9 weeks, which puts harvest in September or October for most of the country.

What yield is realistic? Up to 200g/m² indoors is achievable with competent LED lighting and attention to feeding. Outdoors, Up to 400 gr is realistic in 50 litre pots or in prepared ground with full sun — and "full sun" is doing a lot of work in that sentence at these latitudes, so the position you pick in the garden matters more than the pot you buy. At 18% THC with a terpinolene-forward profile, the return on the effort is sound.

Is it forgiving? Reasonably. Anyone comfortable with pH, a feed schedule and a light timer will get a good result. It will not hold your hand, but it will not punish one missed watering either.

Further questions we get asked about Jack the Ripper

Which medium? For flavour, peat-free soil cut with about 30% perlite and amended slowly — fish, blood and bone, rock phosphate, seaweed meal, all of it available at any British garden centre. For weight, coco with fertigation at EC 1.4-1.8 through bloom. This sativa performs in both; the choice is about what you want out of it.

How does it handle a British summer? Better than most, because the open structure lets heat out. In a genuine heatwave you may see midday droop, with recovery by evening. Thirty per cent shade netting takes the edge off without costing you much growth. The more common British problem is the opposite one: a cold, wet July that never lets the plant dry out between waterings.

When do I switch to bloom feed? Inside the first week of visible pistils. The 25/75 balance shifts its demand quickly at the transition — phosphorus and potassium up, nitrogen down. Soil growers can top-dress with guano and sulphate of potash; coco and hydro should move to a low-nitrogen bloom formula straight away.

Indoors or outdoors? Both work, for different reasons. Indoors you own the flowering environment completely. Outdoors, across the April to October season, the plant gets a light intensity no domestic LED matches and can reach Up to 400 gr — at the price of accepting whatever the autumn does. Flowering: 8-9 weeks. Indoor yield: Up to 200g/m². Outdoor yield: Up to 400 gr. Rated intermediate difficulty.

What Jack the Ripper is actually like

Growers report creative, energetic, happy as the defining characteristics and our own notes agree. At 18% THC this sativa sits where most people find a workable window. Vaporised at 175-185°C the first effect is lift and mental energy, suited to work that benefits from it, a long walk, or an afternoon with company. The body stays light throughout, which makes it a genuine daytime option for anyone with a tolerance. The Terpinolene/Limonene pairing leaves a finish that keeps changing across a session.

Best suited to creative work, company, getting outdoors, and daytime use generally.

Terpene breakdown

Primary: Terpinolene · Secondary: Limonene · Tertiary: Ocimene. This combination turns up often in cultivars that win things, and it is usually the one growers comment on when a jar is opened for the first time after curing. Terpinolene anchors the aroma, limonene occupies the middle, and ocimene sits behind both — which is the part that separates this strain from others sharing its primary terpene.

Who it suits

Jack the Ripper suits growers with the basics in place. Understand pH, rough nutrient ratios and light cycles before you commit to it; it asks for competence rather than expertise. Photoperiod genetics leave plant size and harvest date under your control — veg longer for bigger plants, or flip early when space is short. The April to October season accommodates a bloom of 8-9 weeks comfortably for outdoor growers across the country.

Effects

🤩Creative
77% of people reported feeling Creative
🤑Energetic
64% of people reported feeling Energetic
😊Happy
58% of people reported feeling Happy
😎Uplifted
51% of people reported feeling Uplifted
🤗Euphoric
47% of people reported feeling Euphoric
🧠Focused
42% of people reported feeling Focused
🗣️Talkative
30% of people reported feeling Talkative
💪Motivated
31% of people reported feeling Motivated
😆Giggly
24% of people reported feeling Giggly

Strain Type

Indica 25%Sativa 75%

Strain Data Sheet

🧬THC18% - 21% (Medium-High)
🌿LineageJack's Cleaner × Space Dude
🔬TypeFeminised Sativa
🌡ClimateWarm / Mediterranean, long season
📅HarvestLate Sept – Oct, UK outdoor (typical)
📏Height120 – 200 cm (typical)
⚖️YieldMedium
🏠Yield IndoorUp to 200g/m²
🌳Yield OutdoorUp to 400 gr
⏱Flowering Time8-9 weeks

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 must comply with all applicable United Kingdom legislation.
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Jack the Ripper Feminised
royalkingseeds.co.uk
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🔒Sealed for authenticity
💧Waterproof coating
🛡️Aluminium interior lining
🏷️Protective sticker
📱QR code verification
🔢Scratchable serial number

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Jack the Ripper 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
Royal King Genetics IBL — heritage cultivar restabilisation
Stabilisation Notes — What This Means for Your Grow

Five generations of inbred selection on the original 1990s landrace-derived Jack the Ripper cuts. We were not chasing a redesign — we locked the finished-flower potency that earned this cultivar its reputation. Whatever the next pack throws is what the last pack threw.

Breeding Goal

Pin down the original 1990s landrace-derived terpene profile in modern seed form.

Selection Focus

Chosen for terpene saturation, sativa vigour and a workable finish time despite long-flowering genetics.

Pollen / Mother Source

Royal King Genetics in-house mother stock — pollen taken from a sibling male drawn from the same selected pheno population.

Last Batch QC Verified
31 August 2026· 99%+ germination