Why Do Leaves Change Color in Autumn?

Trees are like giant factories that make food from sunlight. In summer, they keep a green paint called chlorophyll on the leaves to catch sun rays. When autumn arrives, days get shorter. The tree decides it is time to rest and saves its energy for winter.

The tree stops making new chlorophyll. The old green paint fades away like washed-out clothes. This reveals colors that were hiding underneath all summer!

Some leaves have yellow pigments called carotenoids already inside them. You see these in bananas and carrots. Other leaves make red pigments called anthocyanins from leftover sugar. These act like sunscreen to protect the leaf while nutrients are packed up.

Once all the good stuff is stored in the trunk, the stem closes off. The leaf lets go and floats down as a beautiful goodbye gift.