GrapefruitStrain, Effects, Genetics, Grow Guide & Where to Buy
Grapefruit is one of the most-searched cannabis strains in the United States, with a profile that holds up under scrutiny. It is a sativa-dominant (30% indica / 70% sativa) testing at roughly 21% THC, with a flowering window of 8-10 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 Grapefruit seeds in the USA" in one place.
Grapefruit Quick Stats
THC
21%
Indica
30%
Sativa
70%
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
GrapefruitEffects & Experience
The dominant effects of Grapefruit are energetic, happy, uplifted, 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 Grapefruit
Growing Grapefruit fits long-season outdoor zones, Southern California, Arizona, Texas, and Florida, where the extra 2-3 weeks of finishing time is available. Grapefruit 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 defoliate strategically on day 21 of flower; remove fan leaves blocking interior bud sites without stripping the plant. 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.
GrapefruitLineage & Genetics
Grapefruit 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 Grapefruit Seeds in the USA
Grapefruit 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.
Grapefruit FAQ
Is Grapefruit indica or sativa?+
Grapefruit is a sativa-dominant with a 30% indica / 70% sativa split. The effects lean toward mental clarity, mood lift, and conversation.
How long does Grapefruit take to flower?+
Grapefruit 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 Grapefruit?+
Grapefruit tests at approximately 21% 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 Grapefruit good for beginner growers?+
Grapefruit 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 Grapefruit seeds in the USA?+
Royal King Seeds ships Grapefruit 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/grapefruit-feminized, checkout accepts standard cards, Apple Pay, and crypto.