Sirius BlackStrain, Effects, Genetics, Grow Guide & Where to Buy
Sirius Black is one of the most-searched cannabis strains in the United States, with a profile that holds up under scrutiny. It is a indica-dominant (83% indica / 17% sativa) testing at roughly 24% THC, with a flowering window of 9-10 weeks under a 12/12 photoperiod. This guide pulls together the lineage, the effects, the grow data, and the practical answer to "where can I buy Sirius Black seeds in the USA" in one place.
Sirius Black Quick Stats
THC
24%
Indica
83%
Sativa
17%
Autoflower
No
Flowering
9-10 weeks
Difficulty
intermediate
Indoor Yield
400-500 g/m2
Outdoor Yield
400-500 g/plant
Plant Height
Medium
Sirius BlackEffects & Experience
The dominant effects of Sirius Black are euphoric, creative, and the experience is more nuanced than a simple high/low/sedating label would suggest. Onset is gradual rather than abrupt, the peak holds for roughly an hour, and the comedown is smooth, which is why this strain shows up in so many "daily driver" lists from experienced consumers.
Growing Sirius Black
Growing Sirius Black fits shorter outdoor seasons, Pacific Northwest, New England, Great Lakes, where 7-9 week flowering finishes ahead of October rains. Sirius Black is photoperiod, which means you control when it flowers by switching from 18/6 (vegetative) to 12/12 (flowering). Most indoor growers veg for 4-6 weeks before the flip. Indoor yields land around 400-500 g/m2 under quality LED, and outdoor plants given full sun and 5-7 gallon containers reliably produce 400-500 g/plant. Expected plant height is Medium, with intermediate cultivation difficulty. Practical tips that move the needle: apply low-stress training in week 2 of veg, bend the main stem horizontally and tie down to expose lower nodes; and maintain canopy airflow with an oscillating fan moving air through the leaves, not just above them, to prevent powdery mildew. The most common challenge growers report is over-feeding nitrogen past week 1 of flower, switch to bloom nutrients within 7 days of seeing pistils.
Sirius BlackLineage & Genetics
Sirius Black is offered in the Royal King Seeds catalog. Read the description on this page as a general profile rather than a guarantee of your specific pack; expect some phenotype variation between packs.
Where to Buy Sirius Black Seeds in the USA
Sirius Black seeds ship from Royal King Seeds from within the United States. Estimated delivery is approximately 5-7 business days; actual timing varies by destination and carrier.
Sirius Black FAQ
Is Sirius Black indica or sativa?+
Sirius Black is a indica-dominant with a 83% indica / 17% sativa split. The effects lean toward physical relaxation and a calm, settled headspace.
How long does Sirius Black take to flower?+
Sirius Black flowers in 9-10 weeks once you flip to 12/12 light cycle. Outdoor harvest typically lands in late September to mid-October across most US zones.
What is the THC content of Sirius Black?+
Sirius Black tests at approximately 24% THC when grown to its potential. Real-world numbers depend on grow conditions, harvest timing, and curing, well-grown phenotypes can land at the high end of that range, while poorly cured flower tests lower.
Is Sirius Black good for beginner growers?+
Sirius Black is rated intermediate difficulty. Photoperiod genetics give you control over plant size and harvest timing, which means a bit more responsibility for getting the schedule right. Most growers with one harvest behind them handle this strain without difficulty.
Where can I buy Sirius Black seeds in the USA?+
Royal King Seeds ships Sirius Black seeds from within the United States, with estimated delivery in approximately 5-7 business days. The product page is at https://royalkingseeds.us/sirius-black-feminized.