Autumn brings cool air. Green trees start to change. Leaves turn yellow, orange, and red. Why does this happen?
Trees need food to live. They make food in spring and summer. Leaves use sunlight, water, and air to make food. A green thing inside leaves helps do this. It is called chlorophyll. Chlorophyll makes leaves look green when the sun is bright.
Days get shorter in autumn. There is less sunlight. Trees know winter is coming. They stop making new food. Chlorophyll goes away. The green color fades.
Other colors hide under the green all summer. Yellow and orange colors were there the whole time. Now we can see them because the green is gone. Some trees make red colors from trapped sugar inside the leaf.
Trees drop their leaves to stay safe in winter. Cold weather and snow can hurt the tree. Leaves cannot make food without sun and water. The tree lets the leaves fall to the ground. Next spring, new green leaves will grow back.
What color leaf is your favorite?