
Grandpa Larry OG Feminised
Grandpa Larry OG Feminised cannabis seeds for UK growers. Indica · 18% THC · euphoric, creative, calm. Discreet UK delivery, priced in GBP.
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 2026-09-12 on 400 seeds.
About Grandpa Larry OG Feminised
Read Grandpa Larry OG backwards from the harvest: up to 350 g/m2 under lights, up to 400 g/plant outdoors, with resin filling out towards 18% THC. Most of the final weight lands between weeks five and eight, when the 76/24 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 60-70 days of bloom decide whether you reach the top of this strain's range (up to 350 g/m2 indoors, up to 400 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. Caryophyllene 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: 60-70 days. Indoor yield: up to 350 g/m2. Outdoor yield: up to 400 g/plant. Rated intermediate difficulty.
Flavour, aroma and effect
Grandpa Larry OG arrives in stages. The first draw at 18% THC brings dry pepper that registers at the back of the throat. The euphoric, creative, calm character follows within minutes, starting as weight behind the eyes and working down through the shoulders and chest. By about a quarter of an hour it has become a physical stillness — not sedation so much as a strong disinclination to get up. Two to three hours at a moderate dose. The myrcene underneath adds body and depth beneath the rest.
Terpene breakdown
Primary: Caryophyllene · Secondary: Myrcene · Tertiary: Bisabolol. These three build an aroma that keeps moving through the cure. Fresh off the dry it leads with caryophyllene; after three or four weeks sealed in glass at 16-18°C the bisabolol 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 bisabolol molecules are the first thing heat destroys.
Who it suits
Who does well with Grandpa Larry OG? 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
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Strain Data Sheet
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Feminised Premium
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Grandpa Larry OG 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.
Grandpa Larry OG has been the target of countless seed-bank backcross programmes. Ours is BX3 — three rounds of crossing the elite cut back to the parental line until trait expression evened out. The pack grows true to the mother cut.
Translate a clone-only West Coast clone-only cultivar to seed without losing the mother profile.
Chosen for resin density, indica-leaning frame and tight internodes that suit indoor production.
Royal King Genetics in-house breeder room — pollen taken from a generation-tracked sibling-male line.