Every few years, someone will ask me how and why leaves change color in the fall. I love this question. To a child, leaf color change seems like a magical occurrence. Mother Nature sends Jack Frost out to touch the leaves with his icy wand, and suddenly, green leaves turn red and gold and orange.
In reality, a kind of magic does occur, but it is the magic of chemistry, a science that some of us slept through in high school, absorbing just enough to earn a passing grade. I’m not saying I did this, but you know if you did.
In reality, the green leaves of deciduous trees turn color in the fall because of chemical changes that occur to leaf pigments, the most important of which are chlorophyll and the carotenoids. Chlorophyll is the chemical that gives leaves their green hue. Chlorophyll is necessary for photosynthesis, the chemical process by which plants utilize sunlight to change water and carbon dioxide into sugars for nutrition. Carotene and xanthophyll are carotenoids that produce or...