Fall color

Autumn leaf colors in Alabama may be quite bland this year, experts say.

High nighttime temperatures and low moisture are to blame.

“I wouldn’t expect it to be a banner year for fall color,” said Doug Chapman, regional agent for the Alabama Cooperative Extension System and an expert in commercial horticulture.

“We are not expecting a very good fall color, and it has to do with high temperatures in September. The goodies that leaves make — the sugars and the chemicals, including the pigments — get burned up quicker because of higher nighttime temperatures, and that mean less color.”

Chapman explained that if temperatures are high at night, the respiration rate of leaves is faster, so the products of photosynthesis get burned up quicker. Therefore there is not as much color to see.

Temperature, sunlight and soil moisture all play a part in how autumn leaves will look. In the fall, when days grow shorter and temperatures dip, leaves stop their food-making process, according to accuweather.com. The chlorophyll (which makes leaves green) breaks down and slowly disappears, allowing the yellow (xanthophylls) and orange (carotenoids) pigments to be visible. The pigments in the leaves are responsible for the vivid color changes.

Beautiful red, orange and yellow leaves occur in areas where nighttime temperatures are low.

“Nobody goes to Florida to see the fall color,” Chapman noted. “We go to New England or the mountains because the nighttime temperatures are usually lower, so the products of photosynthesis are retained in the leaf.”

According to the U.S. Forestry Service, warm, sunny days with cool nights are the ideal conditions for fall color, but soil moisture is also important.

“Both drought and excessive rainfall can be detrimental to a spectacular foliage season,” the Forestry Service said.

This year, Alabama experienced various degrees of drought, so the prospects for vibrant foliage lessened.

While colder nighttime temperatures help boost the color of leaves, extremely cold temperatures are of no assistance.

“Even without snow, freezing temperatures can destroy the ability of leaves to manufacture pigments,” according to the Forestry Service. “As a result, an early frost or freeze can cause leaves to fall from trees sooner.”

Good place

North Alabamians have about he best seat in the house when it comes to seeing fall color in the state, Chapman said.

“As far as Alabama is concerned, North Alabama is the best place,” he said. “North Georgia, western North Carolina, eastern Tennessee, Virginia and Kentucky are good places in the southern Appalachians.”

What time?

So, when will the leaves peak here?

Chapman said now is the time to see the leaves in the mountains, except he said, “it has been hot and dry up there, too.”

The leaves on many trees in Athens are just beginning to turn from dark green to green tinged with yellow, but leaves on some trees are also falling.

Andy Baril, regional agent for ACES, said the drought has changed what we typically see.

“With the drought we have been experiencing, what’s happened to the oak trees at my house in the Talladega Mountains in Talledega County is the leaves are already falling,” Baril said. “They typically don’t fall until November. If the leaves are already dropping, the intensity of color will be reduced because you don’t have as may leaves on your trees.”

Also, because leaves are falling due to drought, we are seeing color in places now that we typically do not see until the end of the month, he said.

He predicted Athens will likely see peak color the week before Veterans Day, which is Nov. 11.