Gardens that use plants indigenous to our area can be a haven for native critters like the monarch butterfly./Photo by Lori Athey
On a stroll through central Newark, one can expect to encounter the comforts of quintessential suburban life: a droning weed whacker, the sight of manicured yards, the scent of freshly mowed grass.
However, along South College Avenue, one of the University of Delaware’s busiest streets, sits a home that redefines residential beauty and responsibility. With lush gardens in place of perfect lawns and the sounds of birds rather than sprinklers, this suburban oasis seems like it was lifted straight from a fairy tale. Its vibrant flowers and chirping songs are a result of native gardening, a practice that is not only charming but also beneficial to the environment.
“A garden doesn’t have to just be pretty,” says Steve Cottrell, the property’s owner, who also has a home in Landenberg, Pennsylvania. “It can be useful as well. In order to serve a purpose, you have to bring in plants that belong in our area.”
Cottrell, an avid birdwatcher, was introduced to native gardening at a Sierra Club meeting in 2015. A guest speaker from the Audubon Society—a nonprofit that advocates for bird conservation—advised gardeners that manicured lawns may be appealing, but they in fact harm our ecosystem.
Think of a lawn as uninhabitable turf: It looks pretty, but it’s about as welcoming to critters as a golf course. Centuries ago, when Delaware was essentially a large forest, every plant and insect played a specific role in the ecosystem. Eventually, urban development disrupted this delicate balance of give and take. When Cottrell learned that his lawn was taking valuable habitats away from insects and birds, he immediately began planting native trees and flowers at both of his properties.
“I realized that there was no focus to what I was planting … that there could be a larger goal to my gardening, [like] protecting birds,” he says. And so Cottrell removed every plant that wasn’t from North America.
At its roots, the concept of native gardening is simple: Plants are most beneficial to the ecosystem in which they originated. A prime example of this lies in the oak tree, which originated on this continent millions of years ago. Because it evolved within North America’s distinct ecosystem, an oak tree can support about 500 species of butterflies and caterpillars. Most non-native plants can support a handful at best. Many foreign plants may be hardy and less susceptible to pest damage, but they did not evolve to exist with our animals. Choosing these ornamental greens over native species leaves our flora and fauna to deal with shrinking resources.
“One pair of chickadees needs at least 6,000 caterpillars to raise one clutch of chicks,” says Lori Athey, habitat coordinator at the Delaware Nature Society. “So, where are they going to look for food? They’re going to go to the oak tree, which supports plenty of caterpillars. If we’re only planting Asian species, which don’t have the native caterpillars that the chickadees need, then they’ll starve or go somewhere else.”
While well-meaning, America’s appreciation for non-native plants has consequences that vary from merely annoying to entirely destructive. Just as the spotted lantern fly—an insect from Southeast Asia that destroys local crops—wreaked havoc in Delaware and Pennsylvania last summer, non-native plants can also devastate our ecosystem. Many foreign species tend to become invasive, meaning they spread rapidly to overtake native species that are essential to our ecosystem.
The Oriental bittersweet, one of our area’s most invasive plants, is aptly named for both its beauty and lethality. With vibrant orange berries and thick vines, this attractive plant has a nasty habit of wrapping around neighboring trees, thereby squeezing off their access to nutrients. When species like the Oriental bittersweet spread, they reduce native diversity and destroy animal habitats, and can also dangerously alter soil conditions. Though many states, including Delaware, have laws and regulations to keep invasive pests under control, many potentially invasive plants are readily available for purchase in local nurseries. Cottrell warns to avoid common plants like Japanese honeysuckle, multiflora rose and European privet.
“You have to keep an eye out for invasives, because they will always creep in,” says Cottrell, who routinely checks his garden for the aggressive plants. “Once you are able to identify them, you have to get rid of them. In most cases, you can’t just cut them down because they’ll just regrow. You’ll always get invasives because your neighbors are planting them right next door.”
Although using native plants isn’t a new concept in the gardening community, widespread adoption of these practices is becoming imperative. According to the Audubon Society, the United States is now in the midst of a bird emergency. Since 1970, the U.S. has lost nearly 3 billion birds—more than one quarter of the entire population—due primarily to human activities, including urban development and pesticide use.
The abrupt decline in bird populations may seem like the least of our worries, but it’s a precursor to major ecological collapse. Think of it as a domino effect: When we lose caterpillars, we lose birds. When we lose birds, we lose the predators that rely on them. In the greater picture, a simple choice like planting an oak tree supports generations of native plants and animals.
With such strong evidence pointing toward the importance of native gardening, the omnipresence of foreign plants can be puzzling. Why do we continue to plant non-native species when there are hundreds of beautiful local plants? According to Cottrell, it all comes down to supply and demand.
“Right now, the demand is for plants from Asia because that’s all people see their neighbors planting,” he says, noting that he had difficulty finding native woody species in nurseries when he began redesigning his gardens. “What people need to do is request native plants. If the nursery doesn’t have them, complain. We are responsible for creating that change.”
While Athey says she is concerned about the trendiness of nonindigenous plants, she believes that the cultural movement toward environmental awareness is promising. She hopes that education about native gardening will soon overcome the accessibility and convenience of foreign plants.
“When the latest iPhone comes out, people line up to get their hands on it,” she says. “It’s not much different with plants. We are constantly trying to remind people that we still have great native plants that do a lot more than look pretty.”
Understanding the significance of native plants, however, is only one step toward creating healthier ecosystems. Residential gardeners can adopt countless practices that will improve the well-being of their community. According to Doug Tallamy, professor of entomology at the University of Delaware and an expert in conservation biodiversity, there are four goals that every landscape should accomplish: supporting food webs, sequestering carbon, promoting pollinator communities and protecting our watersheds. And all of these can be achieved by reimagining our lawns.
Because of their shallow roots, grassy lawns cannot store as much carbon or rainwater as hardier plants, plus they don’t contribute anything to pollinators like bees and butterflies. To combat this, Tallamy suggests simply downsizing the portion of landscape occupied by pristine green grass.
“There are cultural expectations about what our landscapes look like, and I’m not proposing that we abandon that,” he says. “I’m suggesting ways that we can improve our plant choice and still maintain our aesthetic values.”
Redefining our understanding of residential gardens comes with unlearning destructive habits. Athey notes that when a garden is serving a purpose, it will invite bugs and small animals. While this may sound undesirable, it’s quite the opposite.
“When people see an insect, it’s actually a sign that your plants are working and feeding critters,” she explains. That’s a good thing. “A lot of people see one insect and immediately reach for poison. By doing that, they end up poisoning things that don’t need to die, including whatever eats the insect.”
While chemicals, sprawling lawns and foreign plants remain the standard for most homes, Cottrell is confident that this trend will shift. He argues that the benefits of sustainable gardening—to the environment and in our lives—are too important to ignore. Adopting a meadow-like garden, he says, has allowed him to spend less time mowing and more time appreciating his surroundings.
“In half an hour of sitting outside, I can count 25 or 30 birds,” he says. “If you put in native plants, birds will come, guaranteed. The more plants you bring in, the more life you’ll have.”
Find more than 300 varieties of native wildflowers, trees, shrubs, aquatic plants and more at the Delaware Nature Society’s Native Plant Sale, open to the public from 3 to 7 p.m. on Friday, May 1, and from 9 a.m. to 3 p.m. on Saturday, May 2, at Ashland Nature Center, 3511 Barley Mill Road, Hockessin. (Open from 1 to 7 p.m. Thursday, April 30, for members only). Admission is free. For more information, visit delawarenaturesociety.org.
On Saturday, April 25, the Delaware Center for Horticulture hosts its 40th annual Rare Plant Auction at Longwood Gardens, where horticulturists and plant lovers can bid on an array of rare and beautiful plants, speak with celebrated experts and mingle over food and libations—plus enjoy free access to Longwood for the day. For information and tickets, visit thedch.org.
Published as “Green Gardens” in the March 2020 issue of Delaware Today magazine.