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How Many Woodies Would a Perennials Expert Grow?
If that expert is Tony Avent, the answer is thousands. Well-known for the offbeat perennials in his Plant Delights catalogue, Avent talks of his other horticultural love at Woody Plant Conference.

Tony Advent in Denise Cowie's Backyard
A weeping form of the native Redbud, Cercis canadensis 'Traveler', in Tony Avent's garden.

 
Closeup of Edgeworthia flower in Tony Avant's garden.   The Cercis canadensis 'Traveler,' a weeping form of the native Redbud, in Tony Avant's garden.

        Nobody could call Tony Avent half-hearted about plants.
     The North Carolina nurseryman, plant explorer, and renowned expert on herbaceous perennials waxes poetic in his mail-order catalogue about plants as diverse as Tricyrtis ohsumiensis ‘Nakatsugawa’ from Japan and Aster novae-angliae ‘Purple Dome’ from Delaware’s Mt. Cuba Center.
     But he’s just as obsessed with woody plants, as I found out when I asked him which trees and shrubs he planned to talk about at this year’s Woody Plant Conference at Swarthmore College. Although it was two months before the event, and he hadn’t thought about which plants to highlight, he barely hesitated before launching into passionate praise for Edgeworthia chrysantha.
     “This is my absolute favorite woody [plant] on the face of the planet,” Avent said, lauding the shrub’s long flowering season that runs from winter into spring, the silvery flower buds that look gorgeous for a couple of months before they open to a golden yellow, and the stop-you-in-your-tracks fragrance of the large flower clusters (left).
     More commonly known as paperbush plant, this Daphne relative is not often seen in Pennsylvania gardens. And that’s a major reason Avent wanted to include it in “Falling Off the Cutting Edge,” the title of the talk he planned to deliver at the conference on “some of the newer and more exciting woody plants that are now hitting the market.”

An almost perfect woody plant
     Edgeworthia, Avent said enthusiastically, “is absolutely stunning,” not just in flower (pictured) but in every season. “The leaves are gorgeous, and the bark, and the branching structure.... It is as close to the perfect woody plant as exists. It has no faults.”
     Well, maybe one, if you happen to be a Philadelphia-area gardener: It has a reputation for disliking chilly winters.
     Although Edgeworthia is ideal for Avent’s Plant Delights Nursery and Juniper Level Botanic Garden on the outskirts of Raleigh, many gardening books suggest it may not be quite hardy enough to weather the Delaware Valley’s colder snaps.
     Or is it?
     “I think Edgeworthia is perfectly hardy in Swarthmore,” says Andrew Bunting, curator of Scott Arboretum at Swarthmore College, which was one of the founders of the Woody Plant Conference.
     Bunting thinks that many plants are misrepresented in literature.
     “If we read in a book or a magazine that Edgeworthia is hardy to, say, Zone 8 [on the U.S. Department of Agriculture’s cold-hardiness map], then we as gardeners often take this as the ‘gospel truth,’ or fact,” he says. “But a lot of this, especially hardiness information, is just regurgitated information passed on from one written source to another. It often is not based on someone’s first-hand experience with actually growing the plant.”

For gardeners, it’s love at first sight
     Bunting has hands-on knowledge aplenty. Not only does he have a five-foot-tall Edgeworthia in his own garden, but, as he points out, “We have a fantastic specimen in the Cosby Courtyard at Scott, another one in the Terry Shane Teaching Garden, and we just planted three more in the Entrance Garden.”
     That may explain why 25 Edgeworthias sold out almost instantly at Scott’s biennial plant sale last fall. It’s the kind of thing that happens all the time at Avent’s Plant Delights Nursery, even though the nursery specializes in unusual perennials, not woody plants. But when visitors see the eight-foot-tall shrub in the display gardens at his adjacent Juniper Level Botanic Gardens, Avent said, they rush to the nursery and demand it. So he added the woody plant to his online catalogue (www.plantdelights.com), where – of course – it sold out this spring.
     Avent (pictured in his display garden) was among a handful of horticultural heavy hitters to address the sell-out crowd at the Woody Plant Conference on July 28. Others in the lineup included Ann Fowler Rhoads, senior botanist at Morris Arboretum and co-author of two ground-breaking references, “The Plants of Pennsylvania” and “Trees of Pennsylvania”; and landscape designer Julie Moir Messervy, whose most recent book, “Outside the Not So Big House,” has captured the imagination of gardeners across the country.

Woody plants are critical to a garden
     The annual event is sponsored by Chanticleer in Wayne, Longwood Gardens in Chester County, the Morris Arboretum of the University of Pennsylvania in Chestnut Hill, the Pennsylvania Horticultural Society, Tyler Arboretum in Delaware County, and Scott Arboretum. Its purpose? To stir up interest in woody plants among keen gardeners as well as horticultural professionals.
     That’s no problem for Avent. He may be famous for his cutting-edge perennials and his belief that gardening should be fun (he has given some of his plant introductions names like ‘Heart Attack,’ ‘Redneck Romance’ and ‘Get Shorty’), but Bunting calls his display gardens “one of the greatest collections of woody plants I have ever seen.”
     “I am a fanatic collector of woody plants,” Avent admits, estimating that of the 17,500 different plants he now has growing in the botanic garden, about 5,000 to 6,000 are woodies.
     “It’s critical that you have them in a garden – they are the backbone of the garden.” And for gardeners who don’t know where to start, he urges them to get out into the garden in the cold months to decide what to plant and where to plant it.
     “If the garden looks good in the winter, it automatically looks good in the summer,” he says. “So many people don’t get out there and study their gardens in the winter, with no leaves. ... Landscaping is all about celebrating the natural beauty of the plant – study the form and the shape, and be conscious of what the mature size will be.”

Choosing the appropriate plant for the spot
     So if you yearn for an avenue of Metasequoia glyptostroboides ‘Ogon’ to rival the spectacular allee (pictured) that Avent grows in damp soil at his Raleigh display garden, for instance, you should be aware that these golden dawn redwoods can get to be 100 feet high. But for gardeners with moist soil but less space, there are some new cultivars of look-alike Taxodiums such as ‘Peve Minaret.’ It’s basically a dwarf bald cypress, says Avent, that grows to about eight feet. Or how about a pendulous bald cypress from New Zealand called ‘Cascade Falls’? You could stake it to a certain height and then let it cascade down, Avent suggests. “If you don’t stake it up, it would be completely flat on the ground, which wouldn’t be too useful,” he says. Or you could let it flow over a rock wall like a green waterfall.
     Weeping plants are popular. Avent is excited about some of the colors and forms of newer native redbuds now on the market, including two weeping redbuds, Cercis canadensis ‘Traveler’ and Cercis canadensis ‘Covey’ (pictured below), as well as the brilliant pink flowers of ‘Appalachian Red,’ without a hint of purple, and the double flowers of Cercis canadensis ‘Flame.’
     And there’s “an explosion” of variegated kousa dogwoods in the works, he told the conference audience, which should come onto the market over the next few years. There were two among the eight dogwoods in his lecture – Cornus kousa ‘Summer Fun,’ with a pretty white variegation, and ‘Sun Splash,’ with yellow variegation.
     And don’t forget those Edgeworthias. You can check them out at Scott, or in the gardens of Chanticleer in Wayne or Morris Arboretum in Chestnut Hill. But you could not, as it turned out, see them at the 2006 Woody Plant Conference.
     Avent, possibly saving the best for last, scheduled Edgeworthia chrysantha as Slide 100 – but he ran out of time before he got to talk about that magnificent obsession.