Autumn Foliage Color

The foliage colors at the Harvard Forest in Petersham, Massachusetts, are similar to those throughout the Northeast. The peak of the autumn colors at the Forest arrives between early and mid October, earlier than that in Boston and New York City by about two weeks, and later than central Vermont and New Hampshire by about two weeks. This site will introduce you to those changes and the science behind them.

This page was created in 2004 by Dr. John O’Keefe, Coordinator Emeritus of the Fisher Museum at Harvard Forest, and Dr. David Lee, Biological Sciences, Florida International University. 

The Plants

Description and images of the principal plants that provide a New England autumn's colors.

A Leaf Photo Gallery

A close-up look at the leaves of common trees and bushes. You can see how dramatically different the leaves of many trees and shrubs appear.

The Science Behind the Color Change

Removing the mystery of color change through explanations of leaf pigments, leaf structure and function, the process of leaf color change and the biological significance of color change.

Factors Influencing Autumn Leaf Color

Although always impressive, autumn leaf colors vary from year to year, and seem to be more intense in some regions. What makes for a good year?

Autumn Foliage Color: Past, Present, and Future

Autumn colors were different a century ago in southern New England, and they will likely continue to change during this century. These changes are largely due to human activity, including land-use changes, introduced pests and diseases, forest management, and climate change from fossil fuel emissions.

The Autumn Landscapes at the Harvard Forest

Local autumn landscapes near the Harvard Forest.

Readings About Leaf Color Change

References providing background and recent ideas about the nature and function of autumn coloration.