Temperature Stress Pigmentation

Temperature stress pigmentation refers to the expression of anthocyanins and carotenoids in cannabis plants triggered by exposure to cooler temperatures, particularly during the flowering and late vegetative stages. These water-soluble and fat-soluble pigments produce purple, blue, red, and orange hues in leaves, bracts, and sometimes pistils. The phenomenon is largely phenotypic—environmental rather than purely genetic—though some genotypes show greater predisposition to anthocyanin production under cool conditions. Breeders working with this trait have noted that stable expression often correlates with specific terpene profiles and certain parent lineages, though temperature thresholds and timing remain inconsistent across growing environments.

Breeders select parent plants exhibiting reliable color change under controlled cool-night conditions to stabilize stress-pigmentation traits in offspring. Understanding the genetic architecture behind anthocyanin sensitivity helps breeders develop strains suited to outdoor cultivation in cooler climates or designed for aesthetic consistency in controlled environments.