Seattle Blue cannabis seeds packaging — Royal King Seeds UK
Hybrid
THC 27%
⚡ High Potency
HybridFeminisedIn Stock

Seattle Blue Feminised

Feminised PhotoperiodSee Lab Report →

Seattle Blue Feminised cannabis seeds for UK growers. Hybrid · 27% THC · relaxed, happy, euphoric. Discreet UK delivery, priced in GBP.

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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 2026-09-07 on 200 seeds.

Germination rate: 97.9% (n=200)
Last QC test date: 2026-09-07
Indoor yield: 404-542 g/m² (avg across 16 verified grower reports)
Outdoor yield: 646-858 g/plant (avg across 3 verified grower reports)

About Seattle Blue Feminised

Germination and early veg, days 1-14. Seattle Blue seeds generally crack inside 48 hours on damp kitchen roll and break the surface around day three. Early growth came in even and unhurried, neither racing nor sulking. Four solid nodes by day 14 with the spacing that hints at the hybrid frame to come. Damping off is rare around 70% relative humidity, which is also roughly what an unheated British room sits at in spring.

Veg, weeks 3-6. It took a simple top-and-tie approach well. Topping at node four gave six strong leaders, tied down gently, and an even canopy across a 70cm square by the flip.

Bloom, weeks 1-9. This is where the 44/56 balance in Seattle Blue showed itself. The caryophyllene came up in week three and kept building; trichome cover was obvious to the naked eye from week five. Indoor yield: up to 400 g/m2. THC testing at 27%. Rated intermediate.

The rest of the diary

Mid-bloom, weeks 4-6. The change came quickly. Sites that were loose and wispy at week three closed into defined colas. Development stayed even across the whole canopy, which is what the veg training bought — eight comparable colas instead of one dominant top and a handful of also-rans. Resin was visible to the naked eye from week four.

Ripening, weeks 7-9. Feeding dropped to plain water for the last ten days. The caryophyllene got strong enough that carbon filtration stopped being optional in a terraced house. Trichomes ran clear to milky across the final fortnight, amber showing on sugar leaves first. Around 15% amber on the calyxes is a common place to stop.

Drying and curing. Whole plant hung in the dark at 17°C and 58% humidity for twelve days — both numbers held by a dehumidifier, because an October room in this country will not hold either on its own. Stems snapped rather than bent, which is the test worth trusting. Four weeks in glass followed, burped twice daily for the first fortnight and once daily after. Final weight matched the up to 400 g/m2 figure. The limonene was far more present after the cure than at harvest, which is the argument for curing properly: the process makes flavour rather than merely keeping it.

Flowering: 55-65 days. Indoor yield: up to 400 g/m2. Outdoor yield: up to 400 g/plant. Rated intermediate difficulty. Feminised seeds.

Flavour, aroma and effect

Seattle Blue arrives in stages. The first draw at 27% THC brings dry pepper that registers at the back of the throat. The relaxed, happy, euphoric character follows within minutes, as a head and body effect at once. The mind stays clear while the muscles let go by degrees, which is what makes it adaptable — a small dose carries an afternoon, a larger one turns into an evening. The limonene underneath adds a lift that stops it turning heavy.

Terpene breakdown

Primary: Caryophyllene · Secondary: Limonene · Tertiary: Myrcene. 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. Caryophyllene anchors the aroma, limonene occupies the middle, and myrcene sits behind both — which is the part that separates this strain from others sharing its primary terpene.

Who it suits

Who does well with Seattle Blue? Indoor growers who want the timeline under their own control. Outdoor growers who want to choose when flowering starts. Anyone with the room and the patience to veg it properly before flipping. Difficulty is rated intermediate, which means a moderate learning curve that rewards attention without demanding a laboratory.

Effects

😌Relaxed
72% of people reported feeling Relaxed
😊Happy
65% of people reported feeling Happy
🤗Euphoric
60% of people reported feeling Euphoric
🤩Creative
56% of people reported feeling Creative
😎Uplifted
45% of people reported feeling Uplifted
🤤Hungry
41% of people reported feeling Hungry
😴Sleepy
38% of people reported feeling Sleepy
😆Giggly
31% of people reported feeling Giggly
🧠Focused
21% of people reported feeling Focused

Strain Type

Indica 44%Sativa 56%

Strain Data Sheet

🧬THC27% - 31% (Very High)
🌿LineageBalanced Hybrid (Undisclosed Lineage)
🔬TypeFeminised Hybrid
🌡ClimateTemperate, adaptable
📅HarvestLate Sept – Oct, UK outdoor (typical)
📏Height100 – 160 cm (typical)
⚖️YieldMedium – High
🏠Yield Indoorup to 400 g/m2
🌳Yield Outdoorup to 400 g/plant
⏱Flowering Time55-65 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 must comply with all applicable United Kingdom legislation.
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Seattle Blue Feminised
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🛡️Aluminium interior lining
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🔢Scratchable serial number

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Seattle Blue 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
BX2
Generations
3+
Breeding Programme
Backcross Stabilisation (BX2) — modern hybrid fixing
Stabilisation Notes — What This Means for Your Grow

A modern late-2010s hybrid carrying at least one clone-only parent. BX2 is the right stabilisation point: two rounds of backcross fix the parent-cut traits without narrowing the population too far.

Breeding Goal

Stabilise the Seattle Blue cross into a seed-uniform line.

Selection Focus

Chosen for vigour, terpene saturation and a tight finish window that allows production planning.

Pollen / Mother Source

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

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