Why Do Leaves Change Color in the Fall?
Leaves are basically food-making machines that turn water, carbon dioxide, and sunlight into a nutritious substance called glucose, through a process called photosynthesis. The leaves’ green pigment, chlorophyll, aids the plants in the photosynthesis process. The glucose produced during photosynthesis provides sustenance for plants and trees.
When the days get shorter and leaves are able to absorb less sunlight, trees begin to prepare for autumn by halting the food-making process. The production of chlorophyll drops off and some leaves begin to turn shades of orange and red. The orange and red colors are always present in the leaves, but the powerful green chlorophyll overpowers the hues the rest of the year, when chlorophyll production is in high gear.
September 22 was officially the first day of fall (as of 11:09 p.m. EST), so look for leaves in your area to start changing colors soon!