Associated Press

ASHEVILLE — Forecasters say North Carolina can expect an “average” season for fall leaves, but a college professor suggests it may not be so bad.

The Asheville Citizen-Times reports Appalachian State University biology professor Howard Neufeld says a moderate summer with rain and no drought could help bring out the colors.

Neufeld said it’s been a fairly moderate summer with pretty good rain, no drought and moderate temperatures.

He said if there are clear days in September and a succession of very cool nights and sunny days, that will bring out the red colors.

The fall foliage forecast appears to be a lot brighter than last year. Long periods of heat and drought in the spring and summer of 2016 created a spotty color show.

This spring and summer have been wetter, providing better conditions for trees. But trees also need a little push to be at their prettiest.

“The trick to getting good fall color is some kind of stress. A frost in the first week or two of October triggers the formation of the leaf division. It cuts off fluid to the leaves, and the chlorophyll is not getting replenished. Then it lets the color in the leaves show,” said Dan Pitillo, a retired biology professor at Western Carolina University who used to provide the “official” forecast each season.

Other stressors such as herbicides spread along roadways and disease can also provide for early and brilliant colors, but leaves then often turn brown and die sooner, Pitillo said.

While an early frost is a great stress, storms with high winds and rainfall will blow leaves off quickly, and the season can end as soon as it starts.

Neufeld likes to tell people if they drive up to the Boone area on the Blue Ridge Parkway and find that it’s past peak season, “just look down.”

“There are over 130 species of trees in the Southern Appalachians. We get quite a diversity of color,” Neufeld said. “You’ll hear people say New England has the best fall color, but three species comprise most of their color — birch, beech and maple. We have dozens more species here.”