Highlands, N.C. — The rhododendrons are so dense at Diane Riddle's second home in the mountains of western North Carolina she's tunneled through them — rather than disturb the thicket — to create a passageway to her garden.

The stone and mulch path snakes its way through glades of native ferns and patches of waxy galax, which thrive in Highlands' cool mountain air.

Joey Ivansco/Staff (ENLARGE)

Diane and Jim Riddle, with Dewey, love relaxing in the garden they created after buying a second home in 1990. Diane has designed the garden around nature, with paths navigating glades of ferns, a tunnel through a thicket of rhododendrons and tree stumps converted to planters.

Joey Ivansco/Staff (ENLARGE)

Highlands, N.C., has become a mecca for Atlantans in search of a second home- and many are finding the location quite a change when it comes to gardening. Seasons are shorter and temperatures are cooler, enabling them to grow lots of different things than they do in Atlanta.

MORE PHOTOS • Photos from the tour gardens

"Everything about gardening is different here than in Atlanta," says the Roswell resident, who with her husband, Jim, made Highlands their getaway in 1990. "The heat there keeps us from growing things like rhododendrons, mountain laurel and hemlocks well like we can here."

And to think the Riddles, — like so many Atlantans increasingly dividing their time between the city and Highlands — are only two hours away.

Atlanta is a gardening town, and when its green thumbs establish second homes in this high-end mountain mecca, they're quick to discover — in good ways and bad — that gardening here and in Georgia are worlds apart. As evidence, the Riddles and other Atlantans will be among those opening their gardens next weekend to tours during an annual festival benefiting Highlands' Bascom-Louise Gallery.

"So many people here are into gardening, and with so many of our residents being from Atlanta, it's fun to see what they've learned to do," says Ann Turner, the event's vice chairwoman.

Perched above 4,000 feet, Highlands draws sighs in July when daytime highs top out at 75 and overnight lows dip to the mid-50s, a far cry from sultry Atlanta. Sure, mountainous soil is rocky, but it's also a rich, black sandy loam, unlike metro Atlanta's hard red clay.

But while Highlands' conditions make gardening a no-sweat pleasure, things here aren't always Shangri-la. High winds, temperature variations and, most recently, dry weather, pose their share of challenges.

"The differences in gardening here and back home in Atlanta depend on your elevation and windfall," says Carolyn Tanner, who has escaped to a second home here with her husband, Rhett, for 16 years. "Winds can get up to 70, 80 miles per hour, which in winter burns trees and shrubs. The soil is pretty black, but then our front yard is more like Stone Mountain."

Yet, their mountaintop six acres is proving ideal for a vineyard. "We're at 4,200 feet and growing over 2,000 vines," Tanner says. "This is an Atlanta gal attempting to grow grapes, so you can see why Highlands is just a very interesting gardening paradise."

Chalk it up to the region's origins as one of the country's two rain forests, the other being the Pacific Northwest.

"Ironically, we're in a drought like so many others in the Southeast," Jim Riddle says. "Typically, until a couple years ago, it rained here every afternoon, but now we're almost as dry as Atlanta."

The area's cool temperatures temper the drought's devastation by slowing the soil's moisture absorption.

The Riddles' next-door neighbor, Joanne Long of Atlanta, believes this summer's drier weather has produced a better crop of rhododendron blooms. "This lack of rain is highly unusual for us," says the semi-retired interior designer, whose garden also is on tour.

Like her neighbors, she bought her property with the intention of visiting only on weekends but quickly found she loved the area so much, she's spending more and more time here. After buying her house, she decided to maintain its woodlands site. Moss-lined steps descend a steep hill through glades of native wood ferns, hostas and forget-me-nots.

Three years ago, after losing 21 large hardwood trees in Hurricane Ivan, Long used the downed trunks for terracing the soil along her steep embankment. Her landscaper, Powell Gardens, cut into the slope to create terraces for two ponds, a streambed and 7-foot waterfall.

When it comes to enemies, Long has found that, unlike in Atlanta's suburbs, it's not deer and moles that feast on gardeners' favorites ; here, it's bears and rabbits.

Next door, Jim Riddle, who works in the executive search business when not practicing woodworking, has posted a sign, "Bunny Buffet," marking a log that Diane has cleverly planted with impatiens. Nearby, he has raised their bird feeders out of reach of the bears.

Yet for Atlantans, those gardening challenges don't come close to discouraging the effort.

"This is just a piece of paradise," she says.