Light Cycles

Light cycles refer to the photoperiod schedules—the ratio of light to darkness—that trigger flowering in cannabis plants. Most traditional indica and sativa landraces evolved under specific seasonal light patterns, making photoperiod sensitivity a core breeding trait. Modern cultivation distinguishes between photoperiod-dependent plants (requiring a shift to 12/12 light-dark to flower) and autoflowering varieties (which flower based on age rather than light duration). Understanding light cycle genetics helps breeders stabilize strain characteristics and growers select varieties suited to their environment. Lineage records frequently document whether parent plants carried strong photoperiod-dependency or autoflowering traits, as these deeply influence offspring behavior.

Breeders working in light-cycle genetics select for predictable flowering triggers to control breeding timelines and create stable F1 hybrids. Photoperiod stability is essential for commercial seed production and for developing cultivars adapted to specific growing seasons or indoor schedules.