Grimace cannabis seeds packaging — Royal King Seeds UK
Indica
THC 19%
🎨 Creative
IndicaFeminisedIn Stock

Grimace Feminised

Feminised PhotoperiodSee Lab Report →

Grimace Feminised seeds. A indica cultivar at 19% THC delivering euphoric, 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 2026-09-15 on 325 seeds.

Germination rate: 97.9% (n=325)
Last QC test date: 2026-09-15
Indoor yield: 495-634 g/m² (avg across 15 verified grower reports)
Outdoor yield: 483-810 g/plant (avg across 10 verified grower reports)

About Grimace Feminised

Read Grimace backwards from the harvest: 350 gr/m² under lights, 450 g/plant outdoors, with resin filling out towards 19% THC. Most of the final weight lands between weeks five and eight, when the 79/21 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 56-63 days of bloom decide whether you reach the top of this strain's range (350 gr/m² indoors, 450 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. Myrcene 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: 56-63 days. Indoor yield: 350 gr/m². Outdoor yield: 450 g/plant. Rated intermediate difficulty.

What Grimace is actually like

Growers report euphoric, creative, calm as the defining characteristics and our own notes agree. At 19% 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 Myrcene/Humulene pairing leaves earth and faint sweetness on the palate, with fruit at the end.

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

Terpene breakdown

Primary: Myrcene · Secondary: Humulene · Tertiary: Linalool. These three build an aroma that keeps moving through the cure. Fresh off the dry it leads with myrcene; after three or four weeks sealed in glass at 16-18°C the linalool underneath comes up and the whole thing gains a layer. Vaporising between 180°C and 195°C catches the widest span of them, since the lighter linalool molecules are the first thing heat destroys.

Who it suits

Grimace 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 56-63 days comfortably for outdoor growers across the country.

Effects

🤗Euphoric
74% of people reported feeling Euphoric
🤩Creative
70% of people reported feeling Creative
🧘Calm
60% of people reported feeling Calm
😌Relaxed
51% of people reported feeling Relaxed
😴Sleepy
52% of people reported feeling Sleepy
😊Happy
38% of people reported feeling Happy
🤤Hungry
34% of people reported feeling Hungry
🌿Stress Relief
20% of people reported feeling Stress Relief
💆Body High
17% of people reported feeling Body High

Strain Type

Indica 79%Sativa 21%

Strain Data Sheet

🧬THC19% - 24% (Medium-High)
🌿LineageIndica-Dominant Hybrid (Undisclosed Lineage)
🔬TypeFeminised Indica
🌡ClimateCool–temperate / continental
📅HarvestLate Sept – Oct, UK outdoor (typical)
📏Height90 – 120 cm (typical)
⚖️YieldTypical for type
🏠Yield Indoor350 gr/m²
🌳Yield Outdoor450 g/plant
⏱Flowering Time56-63 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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Grimace Feminised
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🛡️Aluminium interior lining
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Grimace 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
Two-Generation Backcross Programme — recurrent-parent fixing
Stabilisation Notes — What This Means for Your Grow

A modern mid-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

Fix parent-cut traits in Grimace without narrowing the population too far.

Selection Focus

Chosen for purple/dark expression where it shows, dense bud structure and a true indica relaxation profile.

Pollen / Mother Source

Royal King Genetics in-house breeder room — pollen taken from a generation-tracked sibling-male line.

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