
Yumboldt Auto
Yumboldt Auto seeds. A indica cultivar at 15% THC delivering relaxed, sleepy, happy. Grow figures from named sources.
Royal King Genetics β 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 2026-09-19 on 475 seeds.
About Yumboldt Auto
Where you grow Yumboldt 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 β 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 50-60 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 Yumboldt 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.
What Yumboldt is actually like
Growers report relaxed, sleepy, happy as the defining characteristics and our own notes agree. At 15% THC this indica sits where dose control starts to matter. A single bowl through a vaporiser at 185Β°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 β 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 Β· Secondary: Myrcene Β· Tertiary: Caryophyllene. 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. Linalool anchors the aroma, myrcene occupies the middle, and caryophyllene sits behind both β which is the part that separates this strain from others sharing its primary terpene.
Who it suits
Yumboldt 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. Autoflowering genetics take the light cycle out of the equation, which suits balcony growers, anyone working around British daylight hours, and anyone who wants the whole thing over quickly. The April to October season accommodates a bloom of 50-60 days comfortably for outdoor growers across the country.
Effects
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Strain Data Sheet
Packaging
Regular
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Yumboldt Auto β Breeder Information
Royal King GeneticsBred and stabilised in-house by Royal King Genetics β 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.
Yumboldt is our F5 autoflower line. Five rounds of selection have fixed both the autoflower trigger and the indica relaxation profile the cultivar is known for. The recessive ruderalis trait demands this depth of work to express uniformly.
Stabilise the recessive ruderalis trait in Yumboldt for uniform auto-trigger.
Chosen for trichome coverage, stout structure and consistent flowering time across the pack.
Royal King Genetics elite-cut archive β pollen from a maintained S1 line of the original elite mother.