Blueberry plants support 288 species of insects that include moths and butterflies.

by Erin Mooney

When choosing plants to fill our window boxes, decorative planters and gardens, we often are drawn to a plant’s aesthetics — its color, size and texture. Most of us do not consider how that plant fits into the larger ecosystem — that is, what its benefits are to animals and insects.

According to Doug Tallamy, author and University of Delaware entomologist, all gardeners need to begin to consider those benefits when creating their gardens and filling their yards with plants. Each one of us has a larger responsibility when deciding what plants to grow and showcase in our gardens, he says.

Tallamy, whose book Bringing Nature Home has developed a dedicated following among gardeners and conservationists nationwide, will speak in Chestnut Hill on Wednesday, May 21, at 6 p.m., at Valley Green Inn. His program on “Native Gardening: How Native Plants Sustain Wildlife in Our Gardens” will be hosted by the Friends of the Wissahickon.

According to Tallamy it is important that each gardener, regardless of how small the planting area, whether in rural, urban or suburban areas, think about the entire ecosystem with every plant chosen.

Considering how a plant serves animals and insects — and how that fits into the larger landscape, Tallamy says, is crucial, if people, animals and other living things are to co-exist in this overly developed world. To become more-evolved gardeners and to preserve an ecological balance, he says, we need to look past a plant’s beauty.

“We have spent the last century thinking about plants as decorations. We need to start thinking about functioning ecosystems instead,” Tallamy suggests. “And being beautiful just isn’t enough anymore.”

With his background as a professor in the department of entomology and wildlife ecology at the University of Delaware, Tallamy believes that what we each do in our own yards affects every one else – humans and animals alike. “Every little bit helps,” he says.

Animals directly and indirectly rely on plants for their food, so each plant matters. And, the diversity of animals in a given habitat is linked to the diversity of plants in that habitat, Tallamy says. The same goes for insects. So if you have a plant that isn’t hospitable to animals and insects, the ecological balance begins to change.

What can a Philadelphia homeowner do? A major step, Tallamy suggests, is to get rid of lawns, or at least minimize the size of the grass plot on your property. Replace lawns with plants and trees. And, when choosing plants to grow, think about which plants offer more to the ecosystem.

“Not all plants are created equal,” Tallamy says. And most of us need to do a little research before choosing a tree or plant. Take the dogwood, for example. Tallamy says that although they are beautiful, birds can’t eat the berries of some dogwood species. The same thing occurs with some varieties of oak. And ginkoes? Not a good choice. “They’re like plastic to birds,” he says.

Take a walk through your neighborhood and take note of the plants and trees that live there. Some provide all of the benefits that Tallamy talks about, while others simply look good, but aren’t hospitable to other living things.

When selecting plants for our gardens, Tallamy says we have many choices. Native trees like white oaks, black willows or red maples make for excellent habitat for insects and animals, while perennials like joe pye, asters or sunflowers all provide additional benefits to the ecosystem. And they can still be beautiful. His “top 20” list of plants and trees gives gardeners a sense of just how beneficial these plants are. Oak trees and goldenrod both provide the highest level of support to biodiversity, Tallamy says.

Native plants also play a critical role. However, Tallamy says he doesn’t like to frame the debate about native vs. non-native plants. Instead, he says, the dialogue must be about “productive plants,” that is, what is a plant contributing to the native ecosystem? If the energy from that plant isn’t passed on to an insect or animal that uses it, then it’s not productive. For gardeners, native plants are better adapted to the specific growing environment and are less difficult to grow.

Tallamy’s own research has shown that “even modest increases in the native plant cover on suburban properties significantly increases the number and species of breeding birds, including birds of conservation concern.”

Because humans have dramatically changed the landscape, it is up to us to again intervene and realign the balance of the natural world. We all have a role in the survival of the ecosystem, Tallamy says. And the stakes are high. “We must all take responsibility for this, he says, “if we hope to avoid a mass extinction from which humans are not likely to recover.”

Although the message may seem dire, Tallamy says the opportunity exists to work together to create a healthier ecosystem and to prevent a collapse of this interconnected reliance. “There is hope here. We simply need to recognize the need,” he says.

He will discuss these various issues in his presentation, part of the popular lecture series of Valley Talks, sponsored by Valley Green Bank. Valley Green Inn is located on Forbidden Drive in Wissahickon Valley Park. Light refreshments will be provided. Register by contacting Sarah Marley at marley@fow.org or 215-247-0417 x109, or visit www.fow.org.

Erin Mooney is publicist for Friends of the Wissahickon.