From the outside, Disney World's famed topiaries are elaborate greenery shaped into characters in playful poses to entertain theme-park guests.
From the inside, they are engineering marvels, architectural challenges, math problems and horticultural success stories. They survive high winds and pesky squirrels.
The topiaries became part of Disney lore when they arrived at Disneyland 50 years ago this month. They blossomed with the addition of Walt Disney World, growing into a dominant feature of the Epcot International Flower & Garden Festival, an annual event that wraps up Sunday.
Erin Youngs, vice president for Epcot, remembers seeing the greenery during annual family vacations from Illinois.
"I remember as a child, driving around Disney World and seeing the topiaries in the distance," she said. "That was a very unique thing for my family to see. It was so special."
Walt Disney became enchanted with topiaries during a trip to Europe. He wanted some in Disneyland, but he wanted them quickly — faster than a tree could grow large enough to be trimmed into a fanciful design.
He called on Bill Evans, who had landscaped Disney's home in Southern California, according to Orlando-based Disney historian Jim Korkis.
"Walt was the idea guy," Korkis said. "Evans made it work."
Evans devised a shortcut, using steel-and-rebar frame to encourage trees to grow into shapes, Korkis said.
"The first topiaries were not going to be Disney characters," he said. "They were just going to be generic animals, which would theme into the animals you had in the attraction."
The first Disneyland topiary, seen in '63, was shaped like a hippo. Simple forms were trial runs for elephant topiaries at "it's a small world," said Korkis, author of "The Vault of Walt."
The topiary tradition carried over to Florida when Walt Disney World opened in 1971. The popular plantings became an expected feature of the new hotels and at special events, but they were difficult to move, said Renee Worrell, a Disney World topiary specialist and planner.
By the time Epcot opened in 1982, stuck-in-the-ground wooden topiaries were problematic, she said.
A moss-based solution made them more mobile. But then another problem surfaced: keeping them moist.
"Once the moss dries out, it's like concrete. It's hard to get hydrated again," Worrell said.
Character topiaries were equipped with elaborate, slow-drip irrigation systems inside them in the 1990s.
The plain green forms from the early days have given way to detailed designs made possible with natural elements such as begonias, seeds and palm fibers. Topiary faces must remain in character, according to Disney standards.
"Just the slightest change in Donald Duck's eyes can make him look angry or happy," Worrell said.
The steel frames are reused and modified. When a Flower & Garden Festival display called for Mickey Mouse in cookout mode this year, the frame was altered to raise his arm and add a fork. That led to recalculations of how much the arm would weigh — dry and wet — and if the structure could handle that. Designers also must know where the topiary will be located and how sunshine and wind will affect plant growth and hydration.
And there are problems with natural predators, such as squirrels — and people. Animals pull at the seeds used for eyes and attempt to nest in the moss. Two-legged paying guests like to handle the topiaries, causing wear, Worrell said.
"It seems like every single day, we've been repairing them," she said. "But people are curious, and they want to see how things are made."
The topiaries work on multiple levels, said Epcot VP Youngs.
"You can appreciate it from the science and logistics of how they made it. You can appreciate it for the pure beauty of it. You can appreciate it because it's a story that you remember," she said.
"Or it's a child who just responds to the fact that they're standing in front of a 14-foot Goofy."