09/29/2026
🍂 Why do leaves change color in the fall?
During spring and summer, leaves contain large amounts of chlorophyll, the green pigment that captures light for photosynthesis. There are other pigments in the leaf too, but the abundance of chlorophyll largely hides their colors.
As days become shorter and temperatures cool, deciduous trees begin preparing for winter. They stop replacing chlorophyll and actively break it down. In the process, the tree can recover valuable nutrients, including nitrogen and magnesium, before the leaf is shed.
These nutrients are moved out of the leaves and stored in living tissues in the roots, trunk and branches, where they can be reused to support new growth in spring. 🌱
As chlorophyll disappears, the green fades first. Other pigments are more resistant to breakdown and remain in the leaf longer, revealing the yellows and oranges that had been hidden by chlorophyll all summer. In some trees, red and purple pigments are also produced during this autumn transition. 🍁
Eventually, the leaves fall to the ground, where they form a natural layer of insulation over the soil. Throughout winter and beyond, they slowly decompose, returning organic matter and nutrients to the soil and continuing the cycle beneath the tree. 🍂🌳
