Seeing the Fall Forest for the Trees

A kaleidoscope of color defines fall in the Smokies. The hue of a tree’s leaves tell the story of the natural history of each species.

Three pigments fight it out to determine which will prevail as fall arrives, explains Western Carolina University’s fall color expert Kathy Mathews. Chlorophyll, the food-producing part of the leaf, is responsible for any green that’s left around, but most of the chlorophyll dies when frost arrives. Its death reveals the carotenoids that had been there all along and creates colors ranging from yellow to orange. Anthocyanins influence the group of pigments that flash red and purple. The compound is something of a natural sunscreen, produced when sunlight hits the leaves.

For all colors on the fall leaf spectrum, frost is key to setting off the show. Peak color change typically occurs a few days later, explains Mathews.

Generally speaking, peak color comes to elevations above 4,000 feet during the first two weeks of October and to the mid-elevations—2,500 to 3,500 feet—during the third week of October.

A Field Guide to Fall

The Smokies are home to more than 100 species of trees, but those listed here represent the mountains’ most common inhabitants. 

Early fall

• Tulip-poplar, a tall and straight-growing tree that tends to inhabit moist areas, displays yellow leaves often speckled with brown spots. 
• Sweet birch, a medium-size tree that grows at elevations below 4,000 feet, turns yellow. 
• American beech, a high-elevation hardwood, turns golden yellow. 
• Yellow buckeye, named for its yellow flowers that grows in moist forest, turns bright orange. 
• Red maple, a medium-size tree that grows in a wide variety of habitats, turns orange-red. 
• Dogwood, a small tree that grows in all but the highest elevations, turns bright red. 
• Sourwood, a slender tree that often grows at a lean, turns red-purple. 

Late fall

• Hickory, a category that includes multiple species of compound-leafed trees, turns yellow. 
• White oak, which inhabits a range of habitats and elevations, turns orange to yellow. 
• Black oak, which grows in dry areas, turns orange. 
• Northern red oak, which grows on moist slopes and valleys, turns red. 
• Scarlet oak, which grows on dry slopes and ridges, turns scarlet.