One of my favorite things about the fall is the beautiful colors of leaves changing. Bright orange, red and yellows flood college campuses, homes, parks and add a collage of natural beauty to our cities and forests. But have you ever wondered how or why leaves turn this color? Obviously its in preparation for fall and those beautifully colored leaves will soon escape their branches and flutter to the ground, to be laboriously raked up by a high school kid earning extra money for the Homecoming Dance. But before that, before the fluttering, why do leaves TURN such beautiful colors?
National Geographic has a great explanation: “Chlorophyll gives leaves their green color throughout the growing season. The compound is essential for photosynthesis, a chemical reaction that converts sunlight into carbohydrates. Leaves also contain carotenoids. These natural pigments, which produce yellow, orange, and brown hues in plants, from buttercups to carrots, are always present. The colors of carotenoids are easily masked by green chlorophyll, at least until shrinking daylight and a nip in the air signal fall’s arrival. At that time broadleaf plants slow and eventually stop their chlorophyll production, thus revealing the distinctive golden, orange, and yellow hues of carotenoid pigments.”
A lot of big words to basically sum up that the beautiful colors that we see in fall leaves before the cold and stark winter are actually the TRUE colors of the tree, and that the process of photosynthesis that shuts down in fall and winter actual reveals these varied and beautiful pigmentations. So the next time you see one of the most beautiful and rich examples of winter’s eminent arrival, you’ll be able to appreciate the scientific process through which these leaves signal the coming of a dark and rainy winter.