This year's flower show theme - "Passport to the World" - is designed to show off the flora of nations and honor all the globe-trotting Americans who have gone hunting for plants from other lands.
This is no small matter.
The first Philadelphia flower show in 1829 featured the North American debut of the poinsettia from Mexico, the bird of paradise from South Africa, and peonies from China. Today, many other landscaping staples, such as lilies, azaleas and rhododendrons, camellias, hostas, hollies, and hydrangeas, originated somewhere else.
Whatever would we do without them?
"In any garden, even the simplest garden in Philadelphia, at least half of the plants are Asian and half of those are Chinese," says Anthony S. Aiello, horticulture director and curator of the Morris Arboretum in Chestnut Hill. He's gone on five of the arboretum's more than 20 plant expeditions, most recently to central China.
There he collected seeds from native ash trees, which have a natural resistance to the emerald ash borer, a small beetle that has killed millions of ashes in the American Midwest and Western Pennsylvania.
The experiences of Aiello and other modern plant explorers, while intense and sometimes dangerous, are quite different from those of their Indiana Jones-like predecessors in the late 1800s and early 1900s, considered the golden age of plant collecting.
Then, flower-hunters routinely risked their lives on the high seas, in far-off mountains and hostile jungles, to gather specimens for study, to further scientific knowledge, or to plunder at will for commercial profit. Their expeditions could take up to a decade.
When Aiello or Tomasz Anisko, curator of Longwood Gardens in Kennett Square, go collecting in China, a major horticultural hot spot since the 1970s, when relations between the two nations began to improve, they're gone for three or four weeks. They travel with iPods and laptops, on foot but also by bullet train and SUV, and though they occasionally miss out on running water and bathrooms, suffering leeches and bad weather, there are tourist hotels everywhere now - even in the remote countryside.
And today's trips are carefully scripted, with permits, paperwork, legal requirements, and local partners. "It used to be, collectors could go anywhere and take anything. Now, a Brazilian plant is the property of Brazil," says Anisko, who has gone on 16 of Longwood's 50 expeditions - to Asia, Australia, Europe, and South America.
The granddaddy of all such adventures was the Wilkes Expedition, from 1838 to 1842, led by U.S. Navy Lt. Charles Wilkes. His team circled the globe, covering 87,000 often-harrowing miles and 280 islands. He lost 28 men and two ships, and was known for his harsh discipline and obsessive ways.
But Wilkes' five-volume narrative of the expedition, along with 60,000 plant and bird specimens collected, made lasting contributions to science.
Four of the plants he brought back formed the core of the U.S. Botanic Garden in Washington, and two of their progeny will be featured next week at the newly named Philadelphia International Flower Show.
Show designer Sam Lemheney has lined up a New Zealand vessel fern, whose fronds can extend 10 feet, and a couple of sago palms for a display called the Explorer's Garden. "It was really fun to do the research, so many stories," Lemheney says.
Also included in the Explorer's Garden are Longwood's famous water-platters, giant hybrid water lilies developed from seeds collected in South America; the popular annual New Guinea impatiens, from a Longwood-sponsored trip in 1970; and, from Morris expeditions, Chinese witch hazel and Korean flowering dogwood.
Not everyone comes home with full saddlebags.
Harold E. Sweetman, executive director of Jenkins Arboretum in Devon, says his expeditions to India and China, on the Tibetan border, have taken him to some of the most isolated places on Earth, places with astonishing plant diversity. On a single mountain ascent in the Himalayas in 2008, Sweetman's group identified 40 rhododendron species, almost double the number in all of North America.
"For rhodoholics, this was an ascent to heaven . . . an amazing education," says Sweetman, who is less interested in bringing back plants or seeds because of the risk of importing pests or disease. (Such was the case with the chestnut blight and Dutch elm disease.)
Some explorers are hopelessly drawn to the "exotic," suggests Holly H. Shimizu, executive director of the U.S. Botanic Garden, a Philadelphia native and flower show judge.
"Really, still, I find that a lot of people think that for a plant to be beautiful, it has to be from somewhere else. It can't be a native maple. It has to be a Japanese maple," says Shimizu, who collects plants with medicinal value.
Research also motivates collectors, who look for desirable breeding traits, such as toughness or disease resistance. And they seek rare or unusual plants, plants with quirky bark or gorgeous color, or specimens that can add to a nursery's bottom line or a public garden's allure.
Eventually, this can translate into better plants for home gardeners. "You cannot see these things on an iPod or in a photo or on TV," Anisko says. "The only way to know something is to have it."
Having it, whether in your hands or vicariously at a flower show, feeds still more desire. And desire is timeless.
"In the early days of exploration, the thirst for something new and different was there," says Elizabeth McLean, who teaches the history of gardens and landscape architecture at the Barnes Foundation's Arboretum School in Merion.
"Gardeners are the same way. They want something different than what the neighbors have," she says, "something new and different."
Philadelphia International Flower Show
When: Sunday through March 7. Open Saturday for Pennsylvania Horticultural Society members only.
Where: Convention Center, 12th and Arch Streets.
Hours: 8 a.m. to 6 p.m. Sundays; 10 a.m. to 9:30 p.m. Monday through Friday; and 8 a.m. to 9:30 p.m. March 6.
Advance tickets: $23; $18 students (ages 17-24); $13 children (2-16); under 2 free. Tickets at the box office are more, depending on the day of the week.
Information: 215-988-8899 or www.theflowershow.com.
Minas, a Brazilian husband-and-wife band based in Philadelphia, will perform Sunday through March 7, beginning at 11 a.m. daily at intervals ending at 3:15 p.m.
Indian choreographer Rujuta Vaidya and a troupe of Bollywood Dancers will perform Monday through March 6, beginning at 5:30 p.m. at intervals ending at 7:30 p.m. Vaidya, who has worked with Britney Spears, choreographed the Slumdog Millionaire dance sequence at the 2009 Academy Awards.
The Best and Most Bountiful David Austin Roses with Michael Marriott, sponsored by David Austin Roses, will be a demonstration at 1 p.m. Sunday in Room 201-C.
Ten Design Tips for Knockout Gardens with Kerry Mendez, Perennially Yours, will be presented at 5:30 p.m. Monday in Room 201-C.
Vegetable Gardening for Dummies: Growing Edibles All Around Your Yard with Charlie Nardozzi, author of Vegetable Gardening for Dummies. Book signing to follow event at 11:30 a.m. Tuesday in Room 201-C.
What's Wrong With My Plant? with David Deardorff and Kathryn Wadsworth, authors of What's Wrong With My Plant (And How Do I Fix It?). Book signing to follow event at 4 p.m. Wednesday in Room 201-C.
Garden Bouquets and Beyond with Suzy Bales, author of Garden Bouquets and Beyond. Book signing to follow event at 1 p.m. Thursday in Room 201-C.
Bring It Home: Unpack Those Ideas From Garden Tours and Use Them at Home with Marty Wingate, master gardener, presented at 1 p.m. Friday in Room 201-C.
Succulent Container Gardens: Create Easy-Care Pots of Fleshy-Leaved Plants with Debra Lee Baldwin, author of Succulent Container Gardens. Book signing to follow at 11:30 a.m. Saturday in Room 201-C.
Additional information is available by calling 215-988-8899 and at www.theflowershow.com.
Contact staff writer Virginia A. Smith at 215-854-5720 or email@example.com.