This spring, it seems, everyone is celebrating trees.
Three public gardens in the Philadelphia area are launching exhibits featuring tree houses and "canopy walks" - Longwood Gardens in Kennett Square, Morris Arboretum in Chestnut Hill, and Tyler Arboretum in Media.
Longwood went first. Its "Nature's Castles" exhibit opened April 26 with three handsome tree houses: a rustic Adirondack-style Lookout Loft, The Birdhouse in the woods, and a two-story Canopy Cathedral that looks like a basilica for Tarzan.
At a preview last month, children from Pocopson Elementary School raced up the steps of the Lookout Loft, yelling in tandem, "Cool!" and "Awesome!"
"I like how the wood's all different, not just boring, plain wood, and it's fun," said Troy Brown, a third grader from West Chester.
Cool, awesome, fun - these words, coming from kids, make public-garden folks salivate. This is an audience everyone seeks.
Sharon Lee, who helped organize Tyler's tree house exhibit, explains the synergy this way: "Botanical gardens and arboretums are a very safe way to introduce children to the natural world, and tree houses are a natural, alluring way to bring the two together."
The concept has already proved popular at the Atlanta Botanical Garden, the Dallas Arboretum, the Minnesota Landscape Arboretum, and Kew Gardens in England. In fact, it was at Kew four years ago that Paul W. Meyer, Morris' director, got the idea for what will soon become "Out on a Limb - A Tree Adventure Exhibit."
While tagging along on his wife's business trip to London, Meyer went to visit friends at Kew. They introduced him to the Royal Botanic Gardens' "canopy walkway," which was made of sturdy scaffolding and perched high amid some California redwoods and native English oaks.
Then he learned that in its first three months, the exhibit drew 100,000 visitors. "I thought, 'This would be a really cool thing to do at home.' "
Morris' canopy walk, scheduled to open next spring, will be a permanent exhibit mounted among the trees just beyond the visitor center. It will be accessible to wheelchairs, strollers and walkers.
Included will be a partially covered pavilion with views into the woods, a gently swaying rope bridge that's 35 feet long and about 15 feet off the ground, and a suspended bird's nest that's 10 feet across - large enough for Big Bird and humans.
A platform 44 feet off the ground will extend over the steeply sloped woods of the Wissahickon Valley.
"It'll be like you're standing on a third-floor roof. It's where the squirrels go," says Bob Gutowski, Morris' director of public programs. "We want to give people that experience."
Speaking of squirrels, the platform will anchor a triangular rope web, a kind of "squirrel scramble," where kids can jump or roll around the strong netting.
"Kids can climb up against the tree, sit there, and be completely safe," says Melissa von Stade, Morris' development director.
Kew Gardens, by the way, is still at the tree thing. Next week, it opens a four-month "Year of the Tree" festival. The centerpiece attraction, called the Rhizotron and Xstrata Treetop Walkway, will take visitors through an apparent crack in the ground to learn about root systems and then head up into the canopy of chestnut, lime and oak trees.
Trees and tree houses seem to bring out the playfulness in everyone. That's certainly true for some of the entries in Tyler Arboretum's exhibit.
Consider Scared Silly, a tree house that was inspired when three fathers in their 30s, with five kids among them, were sitting around at their children's play group. One of them mentioned a tree house competition at Tyler.
They soon came up with an idea for a tree house called Scared Silly. It's based on a made-up tale about Clarence the Pink Elephant, who scoots up a tree after being spooked by a mouse, then is too frightened to climb down.
The mens' 10-foot-by-6-foot tree house - on stilts - will be in the shape of an elephant. It's one of 16 designs a Tyler jury selected from more than 30 submitted by amateurs and professionals.
Ben Chandler, one of the fathers, says the group had "typical tree house ideas at first," then settled on Clarence after Chris McNichol asked: "What's the most absurd, strange thing you'd find in a tree?"
A pink elephant, of course.
Chandler, a musician and stay-at-home dad, has done some woodworking. McNichol, a farmer, has worked on his house, and Michael Kinsley is an architect.
They're buying materials with a $2,500 stipend from Tyler. They're also Dumpster-diving and reusing things such as flexible ductwork for the trunk and wood pallets painted pink to make Clarence's plank-siding hide.
"We're all conservationists and environmentalists, into recycling and reusing nature," says Chandler, who grew up in Walworth, N.Y., with a tree house that slept five - and was built on stilts.
Learning is a major part of these institutions' tree-centric missions, but fun is central to the mix - especially when the goal is to attract more children and families. The idea resonates with Jane Korman, a longtime Morris board member and a major benefactor for its new exhibit, who has been taking her grandchildren to the arboretum for years.
"Many times, after they'd pumped the water at the log cabin and rolled down the hill, they'd kind of look for something else to stretch their imagination," she says.
Global warming figures into the discussion, too.
"People are wondering . . . what are some of the things everybody can do to fight global warming?" Meyer says. "You can turn down the thermostat. You can drive less, drive a smaller car. You can eat less meat.
"You can also plant trees."
Longwood Gardens' "Nature's Castles" exhibit will be open till Nov. 23, and possibly longer, at 1001 Longwood Rd., Kennett Square. Cost: $1 million. Information: www.longwoodgardens.
org or 610-388-1000.
Tyler Arboretum's "Totally Terrific Treehouses" exhibit runs from May 31 to Sept. 28 at 515 Painter Rd., Media. Sixteen tree houses are being built by two groups - exhibit sponsors, who underwrite their own entries, and designers, architects, builders, artists, students and neighborhood groups. Those in the second category could apply for a stipend of up to $2,500. Information: www.tylerarboretum.org or 610-566-9134.
Morris Arboretum's "Out on a Limb - A Tree Adventure" is slated to begin construction in September and open on Memorial Day 2009 at 100 E. Northwestern Ave., Philadelphia. Cost: $2.7 million, plus a $500,000 endowment. Information: www.upenn.edu/arbore
tum or 215-247-5777.
Virginia A. Smith blogs at http://www.philly.com/philly/blogs/gardening/EndText