Drought shouldn’t dampen this year’s fall color show
Updated: October 14, 2012 12:22PM
LISLE — It’s been a tough summer for trees, shrubs and plants.
But local experts don’t expect this summer’s hot, dry weather to deprive us of a colorful autumn.
“I’m expecting we will see fall color,” said Ed Hedborn, plant records manager and resident fall color expert at the Morton Arboretum in Lisle.
We’re still several weeks away from autumn’s peak, and it is the weather in those coming weeks that will determine this year’s color display, Hedborn said. He said short, hot days and long, cool nights are the triggers that tell trees to start the show.
A leaf’s color change actually comes from the tree’s preparations for winter, said Scott Kobal, DuPage County Forest Preserve District ecologist.
When fall arrives, changes in the weather tell the tree to stop creating chlorophyll. The lack of chlorophyll causes a leaf’s green hue to fade, bringing out other colors that have been there all along.
“The sugar maples usually put on the really good show,” Kobal said.
That’s because they produce red and purple pigments known as anthocyanins, which cover up the yellow that is left when the green fades.
“Not all plants have that ability,” Hedborn said.
Fullersburg Woods in Oak Brook has a big maple population, making it one of Kobal’s favorite places to visit for a fall color show.
Kobal said some especially stressed trees might skip their annual color show and go straight to brown, but that shouldn’t be the norm, he said.
Different species change color at different times, Hedborn said, but the first to change color are those under the most stress. That is why trees along the highway and in mall parking lots tend to show their colors earlier than trees in the forest preserves.
Fall’s color show typically begins with the sumacs, which turn red, followed by Virginia creeper vines, which turn red or purple by mid September.
Next to join the show are burr oaks, white ash and ashberry, among others, followed by sugar maples and white oaks.
Hedborn keeps a constant watch on the progression of color at the arboretum, providing frequent updates on the arboretum’s Bloom ‘n Color Hotline, (630) 719-7955.