
Rockstar Feminised
Grow Rockstar Feminised in the UK. Hybrid genetics at 18% THC, known for happy, relaxed, sleepy effects.
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 2026-09-02 on 475 seeds.
About Rockstar Feminised
Where you grow Rockstar in Britain matters less than when you start it. This is one temperate maritime climate with a real north-south gradient: the south coast opens and closes its season around a fortnight either side of the central belt or upland Wales. Heat is almost never the constraint here. The wet finish is — rain sitting in dense flower through late September and October is what starts botrytis, and it ends more British outdoor crops than every insect on the plot combined. That puts the 56-63 days flowering window and the bud structure ahead of everything else on this page. Under lights none of it applies: daylength, temperature and humidity are yours to set, and Rockstar can be run anywhere in the country on its merits.
The pressures on a British grow are fairly predictable. Damp is the first of them: botrytis in dense flower from September on, answered with open bud structure and moving air rather than with a spray. Indoors it is spider mite and thrips that arrive, and humidity above 60% in late bloom is what turns a contained problem into a lost room. Outdoors in a wet spring the slugs take more seedlings than every insect put together, and they do it overnight.
Flavour, aroma and effect
Rockstar arrives in stages. The first draw at 18% THC brings dry pepper that registers at the back of the throat. The happy, relaxed, sleepy 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. 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 myrcene 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 myrcene molecules are the first thing heat destroys.
Who it suits
Who does well with Rockstar? 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
Strain Type
Strain Data Sheet
Packaging
Feminised Premium
Seeds
authenticity
lining
number
Related Strains

American Strains Pack
Grow American Strains Pack in the UK. Hybrid genetics at 22% THC, known for energizing, happy, creative effects.

Charlie Sheen Auto
Charlie Sheen Auto seeds. A hybrid cultivar at 19% THC delivering euphoric, happy, relaxed. Grow figures from named sources.

OG Chem Feminised
OG Chem Feminised — sativa cannabis seeds suited to UK growing conditions. 20% THC with euphoric, happy, uplifted effects. Fast, discreet UK delivery.

Marcosus Marshmellow Feminised
Grow Marcosus Marshmellow Feminised in the UK. Indica genetics at 14% THC, known for euphoric, creative, focused effects.
Rockstar 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.
A late-2010s cross stabilised over four generations of selection. Rockstar grows true-to-type with the cross-derived trait balance that defines the cultivar.
Cull off-type phenos in Rockstar through filial selection.
Chosen for hybrid frame, clean terpene expression and consistent yield across the population.
Royal King Genetics breeding facility — pollen from internally selected sibling males of the recurrent parent.