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By DR. DIANE RELF Extension Environmental Horticulturist
Only a few regions of the world are fortunate enough to have a display of color when the leaves of the trees change in the fall - Virginia is one of them. Some areas of the state are known for especially beautiful displays. These are the areas with just the right combination of tree varieties, temperatures, and moisture.
Temperature and
daylight make the
difference
The reason leaves of some deciduous, broad leaf trees change color is that variations in temperature and periods of daylight cause the leaves to stop their food-making process. The food-making process takes place in numerous cells of the leaves that contain the pigment, chlorophyll, which gives the leaf its green color. The chlorophyll absorbs energy from sunlight and uses it in transforming carbon dioxide and water into carbohydrates, such as sugar and starch.
Along with the green pigment, leaves also contain orange or yellow carotenoids which, for example, give car
96.8%