Fall Foliage: Why Leaves Change Color and Other Useful Information
Given all that information, have you ever wondered why the leaves change color? Why don’t they simply fall off the trees while they’re still green? Why do they have to fall off the trees (or other wild plants) at all?
As the weather becomes colder and the sunlight decreases, the tree starts to shut down. The trunk and thick branches can withstand a harsh winter, but the flimsy little leaves cannot. So, the tree basically cuts off the food supply to the leaves and any other plant tissue that cannot live through the winter. This is to ensure the tree’s survival. With the exception of Oak leaves, once this food supply cutoff is completed, the leaves fall off the tree. Oak leaves will stay attached to the tree even through winter.
During this cutoff process is when the color changing happens. First, you might see orange or yellow colored leaves. These colors appear when the chlorophyll (which makes them green) goes away. Red coloring comes from the food still trapped in the leaves and the brown colors appear when there is waste trapped in the leaves.
If you’re wondering when the best time is to see the colors, well, that varies greatly. Different trees change color at different times and the zone and climate you’re in also plays a role. However, trees typically change color anytime between late September and early November. It should also be noted that the color of the leaf depends on the type of tree. For example: Oaks and Dogwoods will turn a reddish or brown color, Birches and Poplars will turn a yellowish color, and Maples can turn any shade of orange, red or yellow.
To find out more about Autumn foliage (including some projects for the kids), check out these links:
The Foliage Network
A Complete Fall Color and Autumn Leaf Guide
Why Do Leaves Change Colors in the Fall?
Autumn Leaf Color
Why Do Leaves Change Color?
Why More Autumn Leaves are Red in America and Yellow in Europe
The Science of Color in Autumn Leaves
By Heidi Marshall