Cool Night Terpene Accumulation

Cool Night Terpene Accumulation describes the horticultural observation that cannabis plants often develop more pronounced aromatic profiles during nighttime temperature drops. Breeders and cultivators have long noted that lower evening temperatures—particularly 10–15°C below daytime peaks—correlate with increased volatile compound synthesis in flower tissue. This phenomenon is not universally consistent across all genetics or growing conditions, but lineage records frequently report stronger terpene expression in cultivars grown under diurnal temperature cycling. The mechanism remains incompletely understood, though it may relate to reduced terpene volatilization and continued biosynthesis during cooler periods. Understanding this pattern helps breeders select for genetic stability under varied environmental conditions and informs cultivation protocols aimed at terpene retention.

Breeders working with this trait prioritize genetics that maintain terpene complexity under fluctuating temperature regimes, which improves consistency across different growing environments. Selecting parent plants that demonstrate robust aromatic development during cool nights has become a standard practice in breeding for terpene-forward cultivar lines.