Fall Colors in Trees and Shrubs

Autumn Flame Red Maple (Acer rubrum 'Autumn Flame')

Autumn has arrive once again in our region. Birds are migrating south to warmer places, days are becoming cool and crisp, and fingers are crossed in anticipation that the Chicago bears will make it all the way this year (I'm sure that prayers for the team are in the equation too). Many plants are preparing for the coming winter months ahead that include many physiological changes within the plant. It's these changes that produce some of the most beautiful colors found in nature.

Plants produce several pigments found in their leaves. The most noticeable one is Chlorophyll, the green pigment that is essential for photosynthesis. Chlorophyll is produced abundantly throughout the growing season in order to convert sunlight into energy for growth and development. Mixed in with all that green in the leaf are Carotinoids (oranges), Anthocyanins (reds), and Xanthophylls (yellows). These pigments serve other functions in the leaf such as UV protection. As daylight decreases in autumn, the plant stops the production of Chlorophyll in the leaves, revealing the other colors in the leaf.

There are many factors that play a role in fall colors that occur throughout the growing season. These include relatively good moisture during the spring and summer, warm days and cool nights during the fall, and a location with bright, sunny conditions. Genetics also play a role, and certain tree species produce exceptional fall color better than others. Some of these trees and shrubs include Serviceberries, Sugar and Freeman Maples, Oaks, Birches, Hornbeams, Dogwoods, Sumacs, Hazelnuts, Fothergillas, Witch-hazels, and Black gums. In order to have good fall color year after year, make sure that the plants are in good health. Give them a good soaking once a week during the growing season, and provide a 2-3" layer of mulch around the tree for good moisture control and nutrients. Combine a few of the trees and shrubs mentioned above, and you will have a beautiful display of fall colors to enjoy on a cool, October day!