Black Demon OG cannabis seeds packaging — Royal King Seeds UK
Indica
THC 20%
🎨 Creative
IndicaFeminisedIn Stock

Black Demon OG Feminised

Feminised PhotoperiodSee Lab Report →

Black Demon OG Feminised seeds. A indica cultivar at 20% THC delivering creative, calm. Grow figures from named sources.

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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 2026-09-18 on 475 seeds.

Germination rate: 96.9% (n=475)
Last QC test date: 2026-09-18
Indoor yield: 449-628 g/m² (avg across 17 verified grower reports)
Outdoor yield: 489-758 g/plant (avg across 4 verified grower reports)

About Black Demon OG Feminised

Read Black Demon OG backwards from the harvest: 400-450 g/m2 under lights, 500 g/plant outdoors, with resin filling out towards 20% THC. Most of the final weight lands between weeks five and eight, when the 72/28 genetics stack calyxes quickly and the trichome cover goes from scattered to solid. Outdoors you want that stage falling in late August and early September while the light is still long, so count back to it from the first frost your own area usually sees rather than from a date on a packet.

Getting the weight out of this plant

Three stretches of the 8-10 weeks of bloom decide whether you reach the top of this strain's range (400-450 g/m2 indoors, 500 g/plant outdoors). The rest is maintenance.

The first ten days of flower. What the plant does during the stretch sets canopy height, and canopy height sets how evenly the light lands. Expect 20-30%, which is manageable; stripping the lowest fans around day seven sends the energy up to the sites that will actually finish.

Weeks three to five. Linalool production climbs through here, and it responds to a day-night temperature gap of 6-8°C. British autumn nights hand that to outdoor growers for free from September; indoors you have to build it, at roughly 25-26°C lights-on and 18-20°C lights-off. Bloom feed goes potassium-heavy around EC 1.6-1.8.

The last ten to fourteen days. Stop feeding and run pH-corrected water. Check trichomes daily under a 60x loupe — cut at 15-20% amber for the weight of effect this genetics is bought for. Outdoors that lands between late September and mid-October across most of Britain, and the weather forecast should get a vote.

Flowering: 8-10 weeks. Indoor yield: 400-450 g/m2. Outdoor yield: 500 g/plant. Plant height: 150 cm. Rated intermediate difficulty.

What Black Demon OG is actually like

Growers report creative, calm as the defining characteristics and our own notes agree. At 20% THC this indica sits where dose control starts to matter. A single bowl through a vaporiser at 185°C gives a manageable physical ease with the head still working, which is what most people want at the end of a day. Push the dose and it moves firmly towards sedation — the reason it tends to become a winter evening cultivar rather than an all-year one. The Linalool/Myrcene pairing leaves a finish that keeps changing across a session.

Best suited to quiet evenings, a film, recovery after exercise, and the hour before sleep.

Terpene breakdown

Primary: Linalool · Secondary: Myrcene · Tertiary: Caryophyllene. How this profile survives the journey from flower to vapour depends on temperature. Low vaporisation, 180-188°C, keeps the myrcene and caryophyllene audible over the linalool base. Run it hotter, or burn it, and the three collapse into one note — pleasant enough, but none of the complexity that made it worth choosing.

Who it suits

Black Demon OG 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 8-10 weeks comfortably for outdoor growers across the country.

Effects

🤩Creative
77% of people reported feeling Creative
🧘Calm
67% of people reported feeling Calm
😌Relaxed
58% of people reported feeling Relaxed
😴Sleepy
58% of people reported feeling Sleepy
😊Happy
45% of people reported feeling Happy
🤤Hungry
41% of people reported feeling Hungry
🤗Euphoric
33% of people reported feeling Euphoric
🌿Stress Relief
20% of people reported feeling Stress Relief
💆Body High
17% of people reported feeling Body High

Strain Type

Indica 72%Sativa 28%

Strain Data Sheet

🧬THC20% - 23% (High)
🌿LineageIndica-Dominant Hybrid (Undisclosed Lineage)
🔬TypeFeminised Indica
🌡ClimateCool–temperate / continental
📅HarvestLate Sept – Oct, UK outdoor (typical)
📏Height150 cm
⚖️YieldMedium – High
🏠Yield Indoor400-450 g/m2
🌳Yield Outdoor500 g/plant
⏱Flowering Time8-10 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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Black Demon OG Feminised
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Black Demon OG 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
BX3
Generations
4+
Breeding Programme
Royal King Genetics Backcross Line — BX3 clone-only restabilisation
Stabilisation Notes — What This Means for Your Grow

BX3 is the credible stabilisation point for a clone-only 2010s production cultivar. We worked Black Demon OG through three backcross generations to recreate the elite cut in seed form. A sibling male pollinates the mother each cycle to drive trait fixation.

Breeding Goal

Recreate the Black Demon OG clone-only cut in stable seed form.

Selection Focus

Chosen for trichome coverage, stout structure and consistent flowering time across the pack.

Pollen / Mother Source

Royal King Genetics elite-cut archive — pollen from a maintained S1 line of the original elite mother.

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