Visitors to Western North Carolina’s mountains can look forward to a vibrant display of color this autumn, predicts Kathy Mathews, Western Carolina University’s fearless fall foliage forecaster.
That’s because weather conditions during the spring and summer point to an above-average fall color show, said Mathews, WCU associate professor of biology specializing in plant systematics.
“It’s been a hot year in North Carolina, with above-average temperatures this summer. Rainfall has been slightly less than average during the spring and summer. These are two factors I look at when thinking about the timing and quality of fall leaf color change in the mountains,” Mathews said.
“While your garden may not have fared so well because of the soaring temperatures in June and July, the well-established trees and shrubs of our forests do not appear to have been adversely affected. All of which should lead to very nice color change this October,” she said.
Mathews believes that the formation of ample yellow, orange and red pigments in the leaves seems to correlate with dry weather throughout the year. The drier the climate, the more brilliant the fall leaves tend to be, she said.
“I predict this fall color change will be variable throughout the Southern mountains, but on the whole we should expect to see rich and attractive color change this season.,” she said.
Cooling temperatures during the fall contribute to the decomposition of chlorophyll, the chemical that gives leaves their green color in spring and summer. As chlorophyll breaks down, yellow pigments – always present in the leaves, but masked by the green of chlorophyll – are revealed, and new red pigments are produced.
Although peak fall color typically occurs during the third week of October, the peak may arrive a bit later this year, perhaps more toward the end of October, because of the warm temperatures, Mathews said.
“Peak color corresponds to the first frost date of the year,” she said. “If frost comes later than usual, so will the peak color change of the leaves.”
The color change should begin at the higher mountain elevations in late September and continue through mid-November in the lower levels of WNC.
“Look for the earliest color change to take place on the sourwoods and dogwoods, which both turn red, as well as the tulip poplars, which become yellow but tend to turn brown early,” Mathews said. “Colorful maples, with hues of red, orange and yellow, and birches, which turn yellow, bring us into the peak period. Finally, oaks turn orange and red to round out the later color change in the season.”