Why Do Leaves Change Color?

Part One · The Green Goes

In summer, a maple leaf is green. In fall, it turns yellow, orange, or red. Where do those colors come from?

The green comes from stuff called chlorophyll. A leaf uses it to catch sunlight and make sugar.

All summer, the tree keeps making green. So much green hides everything else.

In fall, the days get shorter and cooler. The tree makes less green. The green fades away.

Yellow and orange were in the leaf all along. The green was hiding them.

Part Two · Reds and the Fall

Reds are different. Many leaves make a new red stuff in the fall.

Reds depend on the weather. Sunny days and cool nights make the best ones.

Not every tree makes red. Some, like hickories and ash trees, go yellow. Maples and sweetgums often make red.

Before the leaf falls, the tree pulls its food back. It saves the food for winter.

Then the leaf drops. A yellow leaf did not really turn. It just lost its green.

So why do leaves change color? The tree stops making green. Then the yellow shows, and some leaves add red.