Specific areas and highways are identified when possible. Many people wonder what causes the leaves to begin changing color in the fall. Contrary to popular belief, frost does not trigger this transformation. Most of the time, the first heavy frost does not occur until the period of color is nearly over. Leaves serve as factories where the tree's food is made.
Chlorophyll gives leaves their green color.
They use sunlight, carbon dioxide, water and other nutrients from the soil to provide the tree with food. Fall begins as the earth tilts on its axis and the sun's rays become less direct, and a chemical reaction is triggered in the leaves. The foodmaking process slows and chlorophyll breaks down, revealing hues of red and causing other chemical changes, which in turn produce other colors. Many warm days and cool nights at the beginning of fall are very good for production of red colors. Cool nights change sugars to red pigment.