Why do trees change color in the fall?

Many people feel that the drop in temperature is the cause. Although temperature has a small function in this process, sunlight is the main reason why leaves turn color. As summer ends and autumn comes, the days get shorter and shorter. This is how the trees “know” to begin getting ready for winter.

During autunm and into winter, there is not enough light for photosynthesis. The trees will rest, and live off the food they stored during the summer. They begin to shut down their food-making factories. The green chlorophyll disappears from the leaves. As the bright green fades away, we begin to see yellow and orange colors. Small amounts of these colors have been in the leaves all along. We just can’t see them in the summer, because they are covered up by the green chlorophyll.