We all marvel at the spectacular colors of autumn. They paint the landscape with an amazing palette of yellow, orange, red, and purple against the shrinking canvas of green. West Virginia offers an extended autumn foliage period starting in August at the highest elevations in our mountain counties and continuing well into October at lower elevations in western counties. Be sure to check our Fall Color Reports for current conditions and best viewing locations.
Autumn colors tell the tale of the seasonal changes taking place in our broad-leaved trees. These trees rely on a steady and unerring signal to start the process of shutting down food production and eventually dropping their leaves. This signal is decreasing day length along with a corresponding drop in temperature.
Our broad-leaved trees use leaves during the summer months to produce food through the process of photosynthesis. The green pigment chlorophyll is necessary for this process to function. When the leaf is actively producing food, chlorophyll occurs at a level that hides or masks two other types of pigments that are also present-carotenoids and xanthophylls. These two pigments are responsible for the yellow and orange colors. The tree slows its production of chlorophyll when the daylight period starts to decrease in late summer. The chlorophyll eventually disappears altogether, revealing these underlying colors.
Another pigment comes into play when certain conditions exist. When night temperatures are low (but above freezing) and days are warm, the level of anthocyanins-those pigments that produce the brilliant reds and purples-increase in the leaf. This is a result of the conducting tissue narrowing and blocking fluid flow to the leaf at the point where the leaf stem is attached to the tree. This blockage traps sugar in the leaf. The combination of trapped sugar and sunlight produces anthocyanins.
The tree continues to sever the connection to the leaf and the leaf eventually drops. Some trees such as oak and beech hold onto their leaves well into winter and may not shed them until new leaves start growing the following spring.
The leaves of our broad-leaved trees are designed for the purpose they serve-food production. They would not function during the freezing temperatures of winter and could be a liability to the tree. After they fall, they decompose on the forest floor and return nutrients to the forest ecosystem.
After the leaves fall to the ground, you can still enjoy the leaves. This is a great time to make a leaf collection and discover all of the different shapes and blends of colors that occur. Leaves can be preserved by pressing them between sheets of newspaper until they are dry (2-3 days) and then mounting them on construction paper. See how many different shapes and color combinations you can find. You can even identify the tree that produced the leaf by observing the leaf shape and other leaf characteristics. Go to leaf identification key.
Our leaf identification key is an Adobe Acrobat Reader document created to work as an online reference as well as the ability to download and print the key to take out on the trails with you.
Our forests are an important part of West Virginia's rich natural heritage. Enjoy the spectacular colors of autumn along our highways and trails!