Summer leaves for fall's finery

Fall foliage frames Emily's Bridge in Stowe, Vermont

By Thurston Hatcher
CNN

(CNN) -- It's a bittersweet conclusion to summer. The nights turn cooler, the daylight hours diminish.

But along the way to winter, the forests' green gives way to a kaleidoscope of color. Nature puts on a final show before calling it a year and wrapping up in winter's grays.

"You get the works, with every hue from bright red to maroon to yellow to gold," says Michael Tougias of Franklin, Massachusetts, co-author of "Autumn Rambles," a guide to leaf watching in New England.

For premium fall colors, you've got to have the right trees, meaning a mix of hardwoods such as birches, sweetgums, hickory, sugar maples and red maples.

EXTRA INFORMATION • When will the color show begin? Check out our interactive map to find out   • It's a snap: How to perfect your photos for the season

As autumn weather kicks in and daylight decreases, trees stop producing the chlorophyll that gives leaves their green hue, exposing yellow and orange pigments that have been obscured all summer. Other chemical changes contribute to the brilliant reds and purples that surface in certain trees.

The leaf elite

Colorado's Vega State Park boasts a high-mountain lake nestled in a beautiful alpine meadow.  

The United States and Canada are among only a few parts of the world that can claim such an array of autumn highlights, says Vic Shelburne, an associate professor of forest resources at Clemson University in South Carolina.

"Eastern North America definitely takes the cake" in fall color displays, he says. Trees in the United Kingdom and western Europe, China and parts of Japan also put on an annual show, he says.

What's the best color-watching spot in the United States? That's like asking what region produces the finest barbecue. Everyone has a favorite.

New Englanders tout their region as the pinnacle of leaf-peeping, from the White Mountains of New Hampshire to the Northeast Kingdom of Vermont.

Not so fast, say others.

Colorado's Vega State Park

"We actually have more hardwood trees species to turn color than New England," says Mary Ann Fajvan, an associate professor of forestry at West Virginia University in Morgantown. "So it's not like that's the only place."

Others favor the Shenandoah, Blue Ridge and Great Smoky mountains of Virginia, North Carolina, Tennessee and Georgia. The Ouachitas and Ozarks of Arkansas have their fans, too.

"Fall is just a beautiful time here," says Kerry Kraus of the Arkansas Department of Parks and Tourism. "It's not just the color but the weather. It's crisp, but it's not too cold. It's just a very enjoyable time to be outside here."

Areas out West can be dramatic, too -- the bright-yellow aspens, for example, are a shimmering example of fall's finest hues -- but the region has fewer hardwoods, says Fajvan. That means fewer colors.

Reaching the peak

It's tough to predict exactly when leaf colors are likely to peak each year, or just how vivid they will be. Too much or too little rain can retard colors. An early frost can kill off the leaves.

Still, leaf watchers can count on bright colors blooming first in the far Northern United States and Canada, usually in mid-September. The hues then trickle downward until hardwoods in the South are ablaze by October or early November.

Tougias suggests travelers might enjoy visiting New England before the peak.

"Early September is beautiful," he says. "You get just a splash of color here and there, and you don't have others to share the roads with."

On the other hand, don't hold off too long to go exploring, or you may have to wait until next year.

"Once they reach that peak in color," Shelburne says, "they're not going to last very long."