18 6 Light Schedule

An 18/6 light schedule refers to 18 hours of light followed by 6 hours of darkness daily, commonly used during the vegetative growth phase of cannabis cultivation. This photoperiod is intermediate between continuous light and traditional 12/12 flowering schedules, often selected to promote leafy, branching growth while managing energy costs. Breeders and cultivators working with photoperiod-sensitive genetics frequently employ 18/6 cycles to extend the vegetative window before triggering flowering with a 12/12 transition. The schedule does not directly produce an aroma but influences plant development patterns that may affect terpene expression over time. Environmental control during photoperiod shifts is a standard breeding consideration for understanding how genetics respond to light-driven developmental cues.

Breeders use 18/6 schedules during selection trials to observe vegetative phenotypes and branching architecture before flowering. Standardized photoperiod protocols help ensure consistent plant structure assessment across seed lines and generation tracking.