Why Leaves Change Color: Light, Not Rain

Settling the Golf Course Debate: Photoperiod Triggers Fall Color

Your buddy thinks July rain made silver maples turn early because “it’s wetter in fall.” You’re right: diminishing daylight (photoperiod) triggers chlorophyll breakdown, revealing yellow/red pigments. Temperature and moisture affect color intensity, not timing. Genetic differences cause individual trees of the same species to turn at slightly different times, but light is the primary cue.

Rain in July doesn’t trick trees into thinking it’s autumn.