Photoperiod Cultivar

Photoperiod cultivars are cannabis plants that require specific light-cycle triggers to transition from vegetative to flowering growth phases. These plants remain in vegetative development under continuous or long-day light conditions (typically 18+ hours daily) and initiate flowering only when exposed to shorter photoperiods, usually 12 hours of uninterrupted darkness. This family represents the majority of traditional cannabis genetics and includes most named cultivars developed over decades of breeding. Photoperiod plants generally allow extended vegetative periods for larger plant development, cloning, and phenotype selection before flowering is initiated. The extended timeline compared to autoflowering varieties requires active light management but offers breeders greater control over plant structure and cannabinoid/terpene expression timing.

Breeders working with photoperiod genetics can maintain mother plants indefinitely under vegetative lighting, preserve elite genetics through cloning, and deliberately time flowering to optimize environmental conditions. This family forms the foundation of most modern breeding programs, allowing controlled crosses, backcrossing projects, and stable line development through multiple generations.