Purple Arrow Auto

We have run Purple Arrow across multiple environments now, and what stands out is the consistency. Whether in a 3x3 tent under LED or a 4x4 with HPS, this indica delivers a myrcene-forward flower at 21% THC that matches the genetic promise. The 79/21 profile shows in how the plant structures itself, bushy, compact, eager to fill lateral space. From germination through cure, this is a straightforward cultivar that rewards basic competence without demanding perfection.

The vegetative phase is unremarkable in the best possible way, steady, consistent growth with no drama in published cultivation reports. After topping at node 4, plants commonly bush out aggressively and fill a 3x3 space by week 5 of veg. The stretch after flipping is minimal, typically a 25-30% height increase.

Flowering completes in 50-60 days. Trichome development typically accelerates in weeks 5-6, and the myrcene aroma becomes unmistakable by week 7. Typical indoor yield: up to 300 g/m2 under LED. Height at harvest: 70–110 cm. Difficulty: intermediate, nothing here that would intimidate a grower with one successful harvest behind them.

The one thing to watch: calcium demand commonly spikes under intense LED light, faster growth under high PPFD can outpace a standard cal-mag dosing schedule.

Purple Arrow at 21% THC produces creative, calm sensations that users consistently describe as physically comforting without being immobilizing at moderate doses. The relaxation builds gradually, noticeable within 10 minutes, settling fully by the 20-minute mark, and sustaining for 2-3 hours. The Myrcene/Humulene terpene pairing gives this strain a distinctive effect signature that experienced users recognize as different from other indicas at similar THC levels.

Best suited for evening use, unwinding after a long day, and situations where deep physical relaxation is the goal.

Dominant terpenes: Myrcene (primary), Humulene (secondary), Linalool (tertiary). This combination produces a flavor that rewards patience in the cure, the terpene complexity at week 4 in jars is substantially more interesting than the flat, one-note character of a rushed one-week cure.

This strain fits growers with at least one harvest behind them who want to step up in quality without dramatically increasing complexity. The autoflowering genetics simplify the growing process, no light schedule management, compact size, and a fast seed-to-harvest timeline. Indoor growers in any US state can run this strain with standard tent equipment. Outdoor growers should match the 50-60 days flowering period to their frost-free window.