The autumnal equinox—also called the September or fall equinox—is the astronomical start of the fall season in the Northern Hemisphere and of the spring season in the Southern Hemisphere. Some consider it to be the most incredible time of the year. Gorgeous colors vibrantly encoring the end of summer as the trees put themselves to bed for the long sleep of winter.
The Science Of It All
It all starts with photosynthesis. Leaves typically produce their vivid hues of green from spring through summer into early fall through the constant creation of Chlorophyll. As we all learned in 5th grade science, Chlorophyll is the key component in a plant’s ability to turn sunlight into glucose, which in turn feeds the trees. Many millions of these Chlorophyll cells saturate the leaves, ultimately making them appear green to the eye.
Did you know?Without the presence of Chlorophyll in the leaf, the bright golds, reds, yellows, and browns would be the natural colors seen year round.
The Changing Colors
Chlorophyll is not the only player in the fall leaf-color game. Present in other leaves and trees are the compounds known as Carotenoids and Anthocyanins. As the Fall days begin to get shorter and shorter, the production of Chlorophyll slows to a hault, eventually giving way to the ‘true’ color of the leaf.