Growing Degree Days
Growing Degree Days (GDD) is a heat-accumulation metric used in cultivation science to predict crop development timelines. It measures the sum of daily temperature differentials above a base threshold (typically 50°F/10°C), accounting for the fact that cannabis development accelerates with warmth. Breeders and growers use GDD to standardize phenotype expression across different climates and seasons, since the same genetic can mature faster in warm conditions and slower in cool ones. Understanding a strain's GDD requirement helps predict flowering duration and harvest readiness independent of calendar days. This framework is especially relevant for outdoor cultivation planning and for breeders working across multiple geographical regions.
Growing Degree Days strains
No strains tagged into Growing Degree Days yet — they'll appear here as breeders submit lineage records under this family.
Growing Degree Days (GDD) is a heat-accumulation metric used in cultivation science to predict crop development timelines. It measures the sum of daily temperature differentials above a base threshold (typically 50°F/10°C), accounting for the fact that cannabis development accelerates with warmth. Breeders and growers use GDD to standardize phenotype expression across different climates and seasons, since the same genetic can mature faster in warm conditions and slower in cool ones. Understanding a strain's GDD requirement helps predict flowering duration and harvest readiness independent of calendar days. This framework is especially relevant for outdoor cultivation planning and for breeders working across multiple geographical regions.
Breeders document GDD requirements to ensure stable phenotype timing across environments and to select for heat-efficient genetics suitable for specific growing zones. Knowing a strain's GDD signature enables more predictable crop cycles and supports regional adaptation programs.
Educational reference · Cultivar metadata only · No medical claims