1:19 p.m., Oct. 4, 2010----University of Delaware entomologist Doug Tallamy has been conducting research studies on the interaction between native plant species and native wildlife since 2000. Author of Bringing Nature Home, which met with critical acclaim in The New York Times and other publications, Tallamy is well aware that most suburban homeowners plant few shrubs and trees, preferring instead vast expanses of grass.
But his latest research, conducted this summer with Jules Bruck, assistant professor of landscape design in the Department of Plant and Soil Sciences in UD's College of Agriculture and Natural Resources, amazed even him. The duo analyzed the composition of 65 suburban yards in New Castle County and Chester County, Pa. They discovered that, on average, homeowners dedicated 92 percent of landscapable areas to lawn.
“I was surprised at how few plants there are in suburbia,” says Tallamy, chair of the Department of Entomology and Wildlife Ecology. “The typical yard is a barren landscape that isn't part of the food web.”
What's worse, he says, is that most of what's planted in suburbia is non-native. In the local yards studied, 78 percent of the plants were alien species. Native plants are necessary to provide food and habitats for local wildlife.
Research shows that people are psychologically more comfortable with empty landscapes, says Tallamy. This mindset is tied into the fact that our earliest ancestors could easily spot predators and other dangers on open terrain.
But saber-toothed tigers aren't lurking outside the palladian windows of our McMansions. So, it's time, says Tallamy, to change the perception of what is an acceptable home landscape.
He doesn't recommend yards brimming with native plants just to be nice to the birds and the butterflies. With every research study he conducts, he's further convinced that healthy local ecosystems are important for people as well as for wildlife.
“Most native insects cannot, or will not, eat alien plants,” explains Tallamy. “When native plants disappear, so, too, do native insects. A land without insects sounds like a gardener's dream; doesn't it? But a land without insects is also a land without most higher forms of life.”
“We invariably take plants and the benefits they provide for granted,” he adds. “Who takes time to think that the oxygen in each breath we take has been produced exclusively by plants?”
Tallamy has enlisted Bruck's help to change attitudes about what constitutes an acceptable home landscape. The duo have begun writing a sequel to Bringing Nature Home that will be a guide to planting with natives in one's local habitat, whether that's the windswept, semi-arid Great Plains or the lush, hilly Piedmont Plateau.
The central question of the book is: How do you design a harmonious garden for people and other things?
“Take what you need and give the rest back to nature,” answers Bruck.
In her own yard, that means some grassy strips for loafing on Adirondack chairs or playing lawn games but also an abundance of native groundcovers, herbaceous perennials, shrubs and trees.
What it doesn't mean is messy, uncontrolled hedgerow, an impenetrable thicket of trees blocking all views or the absence of any lawn.
“No one will accept this new landscape paradigm if it doesn't have curb appeal,” she says.
This isn't theoretical musing but knowledge Bruck has gained from working with residential and commercial landscape clients. In addition to her academic position, she operates Evolution Landscape Design, a consulting firm that does work on Philadelphia's Main Line.
For the most part, people don't want wildflower meadows in their front yards on the moneyed Main Line. Or, here in the Delaware 'burbs, for that matter.
Bruck happens to like the look of home wildflower meadows -- and the fact that they support a variety of wildlife -- but also understands that they aren't right for everyone. Fortunately, there are plenty of other ways to promote biodiversity in the home landscape.
Tallamy believes that Bruck's real-world experience with landscape clients will be a valuable contribution to the sequel to Bringing Nature Home, which, though published three years ago, continues to keep Tallamy on the road with more than 100 public speaking engagements a year.
He acknowledges that his personal approach to his 10-acre yard in Oxford, Pa., is less about curb appeal and more about unabashedly fighting habitat loss.
For example, he's reluctant to pull out saplings, even in odd places, like the black cherry that sprouted right beside his back door.
The day that Tallamy intended to remove the sapling it had tiger swallowtail larvae all over it. Not surprisingly, that black cherry still flourishes there today.
Article by Margo McDonough
Photos by Danielle Quigley