Short Day Plant

Short day plant refers to cannabis cultivars that initiate flowering based on photoperiod cycles, typically requiring 12 hours or less of daily light to trigger reproductive development. This trait is fundamental to photoperiod-dependent breeding programs and represents the ancestral flowering pattern found in most cannabis landraces. Breeders distinguish short day varieties from autoflowering lines, which flower based on age rather than light cycles. Understanding photoperiod sensitivity is essential for controlled breeding, seed production, and predictable crop timing in indoor cultivation environments.

Breeders working with short day genetics rely on precise light schedules to control flowering timing and ensure stable seed production. This photoperiod dependency allows for extended vegetative growth before triggering flowering, enabling larger plant development and extended selection windows during breeding programs.