Photoperiod

Photoperiod is not a terpene but rather a plant biology mechanism—the flowering trigger based on light exposure duration. Cannabis plants are classified as short-day organisms, typically initiating flower when receiving approximately 12 hours or less of uninterrupted darkness. This trait is fundamental to cannabis cultivation and breeding programs, as it determines whether a plant is photoperiod-dependent (requiring light-cycle manipulation) or autonomous (autoflowering). Understanding photoperiod response is essential for indoor growers managing bloom cycles and for breeders developing cultivars suited to specific growing regions and seasons.

Breeders leverage photoperiod genetics to create regionally adapted varieties—long-day photoperiods for high-latitude grows, and photoperiod-independent autoflowering lines through Cannabis ruderalis introgression. Photoperiod stability and sensitivity are key selection criteria when developing reproducible cultivars for commercial or regional cultivation.