HIGH COUNTRY — Pumpkin patches are populating, there is a chill to the early morning air, football is back and autumn has arrived as of 9:54 p.m. Saturday, Sept. 22, the exact listed time of the 2018 fall equinox.
To leaf-lookers’ delight, peak leaf season in the High Country is looking like Oct. 1 to 21, according to a fall color map created by the Department of Biology at Appalachian State University.
The fall color map, conceived by two members of the ASU Department of Biology, Michael Denslow and Howard Neufeld, also known as the Fall Color Guy on Facebook, attempts to estimate the timing of fall color peaks for the various regions of western North Carolina, according to the department’s website.
“This map differs from most other such maps because it combines the effects of both elevation and latitude on fall color, whereas most other maps simply use elevation alone,” the map’s description said.
The fall color map is constructed based on the assumptions that fall color starts earlier at higher elevations, and that peak fall colors occur about a week earlier for every 1,000 feet of elevation, according to the ASU Department of Biology.
“For the latitude effect, we used data from published papers suggesting that each degree of latitude north is equivalent to going up in elevation by about 656 (feet),” the fall color map description said. “This means that if you were to compare 3,000 (feet) down in Murphy with 3,000 (feet) in northern Ashe County (which are about 2.5 degrees apart), it would be as if you were really at 4,640 (feet) in Ashe County, at least fall color peak-wise.”
Simply, the same elevation further north is cooler than that same elevation further south, resulting in earlier fall peak colors further north, according to the ASU Department of Biology.
Neufeld said in an email that the High Country should expect a colorful leaf season.
“I think we’re still in for a good fall leaf color season, providing we get some relief from the above-normal temperatures — we’re averaging somewhere around 5 to 7 (degrees Fahrenheit) above normal,” Neufeld said. “The best colors occur when we get a cool down in September, coupled with sunny days.”
Cool days and cool nights, along with sunny days, promote the best fall leaf color, especially for trees that turn red, Neufeld said. Conversely, if weather stays warm or gets cloudy and rainy, red leaves tend to dull, according to Neufeld.
“Hurricane Florence had only a minor effect in the mountains of Western North Carolina, so as a result, most of the trees held on to their leaves,” Neufeld said. “We lost a small percentage of leaves, but because the trees were still mostly green, they were held more tightly than if the hurricane had come two weeks later — that might have negatively impacted fall leaf color season.”
Some trees turn colors based on temperature, whereas others track sunlight and turn as the days get shorter, Neufeld said. Dogwoods color up early, along with red maples, sugar maples and sourwoods, while oaks are notoriously late to color up, according to Neufeld.
“Of course, there is always some difference in timing among different tree species, even in good years,” Neufeld said. “Dogwoods color up early, along with red and sugar maples, and sourwoods, while oaks are notoriously late to color up.”
Neufeld said colors develop earlier at higher elevations, and then march downslope at about 1,000 feet every 10 days, as is shown on the fall color map.
“If it gets cooler — temperatures are predicted to go down next week — and we get some nice sunny days, we should have good color this year,” Neufeld said. “Drought, which could cause leaves to drop early, will not be a factor this year.”
“If it stays warm, colors may be delayed by three to five days, and perhaps not as intense,” Neufeld said. “Since I can’t predict the weather too far in advance, that is the best I can do at this point in the season.”