What causes the brilliant colors of fall?
With the colorful fall days ahead in Raleigh, it’s interesting to know why the leaves change color. Not everything is known about what affects fall leaf color, but here are some of the basics.
Weather, temperature and the longer nights in autumn all affect leaf color to some degree. Yet, it is the chemical processes in the tree that affect the three pigments present in leaves: chlorophyll, carotenoids, and anthocyanins. Specifically, as the nights get longer, leaves stop their food making process. Chlorophyll, the pigment that gives leaves their green color and is also necessary for photosynthesis slows down. So, leaves lose their green color. When this happens, the carotenoids and anthocyanins in the leaves are exposed and reveal the brilliant orange, red and yellow colors of autumn.
Temperature and moisture also affect the degree and duration of fall color. A series of warm, sunny days and cool nights that remain above freezing produce the most brilliant colors. Yet, a summer drought or an early spring can delay fall leaf color change. Ultimately, it’s the combination of warm sunny fall days and cool nights, agreeable summer weather and a wet and warm spring that produce the most brilliant color we all long for in fall.
We hope you can get outside and enjoy the cool, crisp air and the brilliant colors this season has to offer. Happy fall y’all!