Autumn’s Leaf Show is On
Photos by Sheryl DeVore
Each fall, “leaf peepers”, or foliage enthusiasts, head outdoors to view the yellows, oranges, reds, purples and browns that cover the deciduous trees and woodland floors. They often wonder, “What will the colors be like this year and where is the best place nearby to see the most splendid views?”
“The only thing autumn lovers in the Midwest can count on is that as the daylight hours diminish, the leaves will start to change colors,” says Ed Hedborn, manager of plant records at the Morton Arboretum, in Lisle. “Other than that, predicting the intensity and duration of fall color in the Chicago region is as about as easy as predicting the weather. The main trigger for leaves to start changing colors is the amount of sunlight hours—it’s one of the biological clocks plants keep track of.” Then it’s up to the weather to decide the rest.
The most intense colors come with warm, sunny days, cool nights and adequate moisture. Hedborn says. “All bets are off if there’s a week of 90-degree temperatures or strong winds that can cause the leaves to fall prematurely.” Plants drop their leaves to prepare for winter, and the color change is part of this process. Plants stop producing chlorophyll, the food-making pigment that makes the leaves green. Then other color pigments that were masked by the chlorophyll during the growing season can shine through.
“When the green fades out of a redbud leaf, for example, you’ll see the yellow pigment that was there all summer,” Hedborn says. “Red and purple colors also appear in some leaves, depending on the weather and the health of the plant. That’s why from year to year, the same individual sugar maple could be yellow, bright red, orange or a combination of colors.”
A tree’s color in autumn also depends on how much sunlight it gets. Shaded trees might hold onto the green longer, while trees along streets could change colors more quickly. Leaves on the outside of the tree often turn color before those on the inside because they are receiving more sunlight, which signals the shortening of the days. “Drought conditions in fall could cause the leaves to change colors early as they try to conserve water, Hedborn says. “The weather conditions, brightness and amount of color could vary, even from town to town.”
Plants change colors in succession in the region. Virginia creeper vines turn red in September, followed by the pumpkin color of Ohio buckeyes. Soon after, the hickories and elms turn yellow, followed by the sugar maples, which can take on a variety of hues. The white and red oaks turn brownish to reddish to russet toward the end of October. The peak time—when the most kinds of colors are seen—is typically during the second or third week in October in the Chicago region.
Hedborn suggests not worrying so much about the when and where of colors. “Enjoy it whether it’s in the neighborhood, a local park or a forest preserve,” he says. “The main thing is get out, get the exercise, enjoy the colors even as the leaves drop. Notice how the light changes in the woods going from dark and green to a sort of yellowish or golden color, getting brighter and brighter, and the smell of the woodlands that says it’s autumn.”
Hedborn goes out daily at the Morton Arboretum to see which trees are changing colors, and his report is posted online at MortonArb.org. The Chicago Botanic Garden, in Glencoe, provides another suggested walk to see the colors (ChicagoBotanic.org). An entrance fee is charged at the Arboretum; a parking fee is charged at the Botanic Garden.
For more information, visit EnjoyIllinois.com/plan-your-trip/seasonal-adventures/fall-travel-in-illinois/illinois-fall-color-report.
Sheryl DeVore is a Chicago area writer, editor, educator, photographer and author of three books on nature. For more information, email Sheryl.Devore@comcast.net.
Local Places to See Great Fall Color
Here are some forest preserves to explore fall colors for free in the region.
Ryerson Woods, Deerfield: Sugar maples turn yellow, orange and red, and shagbark hickories turn yellow, peaking in mid-October.
Volo Bog, Ingleside: Tamaracks turn golden on the interpretive board walk, peaking in late October to early November.
Coral Woods, Marengo. The 297-acre maple forest can be painted with red, gold, yellow and orange hues in early to middle October.
Rush Creek, Harvard, has stands of hickory, white oak and red oak, showing subdued hues of yellow, brown and orange.
Paw Paw Woods, Willow Springs, contains bluff and floodplain forests that sparkle with color throughout October. Oaks and sugar maples dominate.