Published on 10/04/06

Nature creates a colorful fall leaf display

By Sharon Omahen
University of Georgia

If leaf-watching is a traditional part of your fall outings, it's time to plan your trip to the Georgia mountains. University of Georgia professor Kim Coder says Oct. 18 through Nov. 8 are the best times to see nature's color display.

A UGA Warnell School of Forestry and Natural Resources tree health care specialist, Coder uses his personal leaf color model that is based on climate and tree health factors to estimate the peak times for viewing yellow, orange and red leaf color waves.

Orange peak = Nov. 1

"This year's peak for orange coloring is predicted at Nov. 1, so good viewing should be two weeks ahead of this date and one week past it," he said.

He suggests mapping out two routes for your leaf-watching trek.

"Take one northbound Georgia highway up and come back on another," he said. "Once you reach your destination, get up high to see the best color distribution."

Nature's fall color display is the result of trees' natural living processes.

"Dead leaves just turn brown and fall, but living leaf tissue develops color with bright days, cool but not freezing temperatures and a slight drought," Coder said. "Hard freezes or frost at night, overcast and wet conditions can damage color formation, and a big, windy storm front can blow all the leaves off the trees."

A natural process

Trees naturally turn color this time of year as they enter what Coder calls "a resting phase of their lives."

"The chlorophyll breaks apart, and the supporting leaf tissues are sealed off from the tree and allowed to die," he said. "This process allows new pigments to be made and old pigments to be revealed."

Red, yellow and brown are the colors most people equate with fall leaf color. But Coder says many more colors are on nature's palette.

"The three color systems tree leaves use are bright yellow to bright crimson oil colors, blue to deep purple water colors, and tan to dark brown earth tones," Coder said. "Some trees, like sweetgum, can have all three colors on one tree. Other trees, like some oaks, have reds and dark reds all over the crown."

Display flows south

If you don't have the time or money to travel north, you can still enjoy fall leaf color displays.

"Because of cool, bright and clear conditions, the colors start at higher altitudes and flow downhill into the valleys headed south," Coder said. "There are three color waves that pass through seven to 16 days apart, depending upon the year. A yellow wave first, then an orange wave and finally a red wave that leads into winter."

So, if you can't get to the mountains for the first wave, stay where you are and the color will come to you.

Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.