As fall approaches, leaf-peepers across the South Carolina Upstate eagerly anticipate the annual transformation of forest canopies into brilliant displays of red, orange and gold.
According to a Clemson University scientist, the 2025 fall leaf color season in the southern Appalachian Mountains is off to a promising start despite some damage from Hurricane Helene.
“So far so good,” said Don Hagan, associate professor of forest ecology. “Most trees made it through the summer without losing their leaves. Sometimes drought causes certain species to drop their leaves early, but we didn’t see much of that this year.”
Having a full canopy is the first prerequisite for vibrant fall color. Hagan emphasized that the weather during the summer-to-fall transition will ultimately dictate the quality of the season.
“Ideally, we’d see a gradual transition into fall, with a series of mild cold fronts followed by clear, cool days, no early frost, no lengthy periods of gray or soggy weather, and definitely no hurricanes,” he said.
Timing the peak
Leaf color changes will vary by elevation. Higher elevations—above 5,000 feet—are expected to peak in early October. For every 1,000 feet decrease in elevation, peak color will occur roughly a week later. Areas in the Upstate should see their most vivid displays around the first part of November.
Hagan said cooler, drier weather at the end of the summer has caused some species’ leaves to begin changing early.
“Just because the leaves have started changing colors a little early doesn’t necessarily mean the color season will peak early,” he said. “The timing of the peak will be dictated by the weather we see during the summer-to-fall transition.”
Travel tips and road closures
While many popular leaf-viewing destinations will be open, some traditional spots remain inaccessible due to road closures caused by Hurricane Helene.
“Certain sections of the Blue Ridge Parkway, for example, are still closed,” Hagan noted. “Travelers should consult the Parkway Road Conditions website before heading out. There are still plenty of good places to visit. This could be an excellent opportunity to explore new routes and drive back roads they usually don’t take.”
Hurricane Helene’s impact on forests
Hurricanes like Helene can significantly alter forest canopy structure and affect leaf color.
“Hurricanes damage tree canopies and can overthrow individual trees or level entire sections of forest,” he said. “In the short term, this creates visible damage, causes road closures and increases wildfire risk. In the long term, it creates opportunities for new, young trees to establish.”
Gaps in the tree canopy allow more sunlight to reach the forest floor, enhancing fall color displays.
Sunlight triggers a reaction in some plants that causes anthocyanins—a type of pigment—to form. Anthocyanins are responsible for the bright red, pink and purple colors that some trees produce.
Species such as dogwoods, sourwood, blackgum, sassafras, sumacs and maples are particularly likely to show enhanced coloration due to increased light exposure.
“Smaller, light-demanding trees will begin to grow in the canopy gaps,” Hagan said. “Many of these species produce bright fall colors.”
Stress and coloration
Interestingly, fall leaf color is fundamentally a stress response in trees.
Stressors, like root disturbance or broken limbs from hurricane damage, can influence pigment production.
“Stressed trees may change color earlier than normal,” Hagan said.
These changes may be noticeable immediately and persist for several seasons, until the forest canopy returns to its pre-hurricane state. Canopy gaps also alter the forest’s microclimate—changing temperature and humidity levels. These changes can influence leaf development and coloration.
“As long as canopy gaps from the hurricane are still present, the light and microclimate will be different,” Hagan explained. “This will influence the amount of sunlight that reaches the lower canopy and forest floor and the types of vegetation that establish there.”
For information, contact Hagan.
