Why fall foliage occurs

There are 3 main chemicals responsible for autumn colors; Chlorophyll, Carotenoids, and Anthocyanins. Chlorophyll is the chemical responsible for creating sugar and thus giving the green color in plants. During the warm season, there are more daylight hours then night time hours. In order for photosynthesis to occur, and Chlorophyll to produce, there must be more day light. Carotenoids are responsible for the production of orange and yellow colors, while Anthocyanins are responsible for red and purple colors. All compounds are occurring, with Chlorophyll being dominant, which is why we see the green colors during the spring and summer months.

When we lose daylight hours, there is less production of Chlorophyll, allowing the oranges, yellows, and reds to reveal. Temperature and moisture from previous months can delay colors changing, and impact how vibrant the colors may be. During a dry season, due to less sugars during the growing season, colors will be less vibrant. When temperatures are above freezing for a longer period heading into the cool season, this can prolong the vibrant colors. If it becomes cold and freezes early, this causes leaves to turn and fall off branches much quicker, meaning the autumn colors don’t last as long, and aren’t as vibrant . For additional weather updates follow @ABC17Stormtrack on Twitter.