Sour JackStrain, Effects, Genetics, Grow Guide & Where to Buy
Among the strains American growers consistently come back to, Sour Jack sits near the top of the list, but the data behind the hype is what holds growers' attention. It is a sativa-dominant (18% indica / 82% sativa) testing at roughly 15% THC, with a flowering window of 8-10 weeks under a 12/12 photoperiod. On this page we cover the effects, the lineage, the grow profile, and where to buy Sour Jack seeds in the United States with discreet shipping and a 95% germination guarantee.
Sour Jack Quick Stats
THC
15%
Indica
18%
Sativa
82%
Autoflower
No
Flowering
8-10 weeks
Difficulty
intermediate
Indoor Yield
450-550 g/m²
Outdoor Yield
500-700 g/plant
Plant Height
120-180 cm
Sour JackEffects & Experience
Reported effects center on uplifted, energetic. Sour Jack pulls toward mental clarity, conversation, and a light, mobile body feel, a profile that holds up across phenotypes when the seeds are grown to their potential.
Growing Sour Jack
Growing Sour Jack fits subtropical and Mediterranean climates with dry late-summer weather to support the longer flower window. Sour Jack 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 450-550 g/m² under quality LED, and outdoor plants given full sun and 5-7 gallon containers reliably produce 500-700 g/plant. Expected plant height is 120-180 cm, 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 feed cal-mag from week 2 onward at 2-3 mL per gallon, most reverse-osmosis and soft tap water setups need it. The most common challenge growers report is calcium and magnesium supplementation under bright LED lighting; cal-mag at 2-3 mL/gal from week 2 prevents the most common deficiency.
Sour JackLineage & Genetics
Sour Jack is a Royal King Genetics in-house cross. The parental selection was chosen for cerebral effects and aromatic complexity, then stabilized over multiple generations to lock in phenotype expression. Seeds run true to the description on this page rather than spreading across a wide range of expressions.
Where to Buy Sour Jack Seeds in the USA
Sour Jack seeds ship from Royal King Seeds to all 50 US states with discreet packaging and a 95% germination guarantee. Average delivery is 3-5 business days, with the fastest routes typically reaching Alaska, Arizona, Arkansas, California, Colorado.
Sour Jack FAQ
Is Sour Jack indica or sativa?+
Sour Jack is a sativa-dominant with a 18% indica / 82% sativa split. The effects lean toward mental clarity, mood lift, and conversation.
How long does Sour Jack take to flower?+
Sour Jack flowers in 8-10 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 Sour Jack?+
Sour Jack tests at approximately 15% 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 Sour Jack good for beginner growers?+
Sour Jack 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 Sour Jack seeds in the USA?+
Royal King Seeds ships Sour Jack seeds to all 50 US states with discreet packaging, 3-5 day delivery, and a 95% germination guarantee. The product page is at https://royalkingseeds.us/sour-jack-feminized, checkout accepts standard cards, Apple Pay, and crypto.