If you’re a gardener, you likely have heard about and even engaged in debates about the use of native plants versus imported species.
Native plants are part of the natural environment. They are easier to grow because they have evolved to subsist on an area’s traditional rainfall levels and live in relative harmony with the soil, plants and insects in your garden.
Yet non-native plants – also known as exotics or aliens – have been linchpins in American gardens for more than a century. Drive through any neighborhood in the Triangle and you are likely to spot multiple examples of English ivy, Chinese privet and Bradford pear trees – just to name a few.
As Douglas W. Tallamy points out in his excellent book “Bringing Nature Home,” a century of importing beautiful exotic plants and grasses has caused some unintended consequences. Many have become invasive, growing out of control, their seeds spread by birds or other animals. Others, lacking local competitors for space and sunlight, spread on their own. Kudzu, for example, or Japanese honeysuckle.
As a wildlife gardener, you can add yet another reason to choose natives over exotics: They are key to the preservation of wildlife, say Brian Hahn and Kim Smart, who run the N.C. Museum of Natural Science’s Prairie Ridge Ecostation in West Raleigh off Edwards Mill Road.
Prairie Ridge is a 45-acre tract in dedicated to the nurturing of the original landscape in our area: Piedmont prairie. This landscape includes forests, ponds and streams and many wildlife-friendly features, such as undergrowth for nesting and protection and plants that attract nutritious insects.
“If you want to notice the difference between native and non-native plants, just visit a Lowe’s or Home Depot,” Hahn told me. “The exotic flowers are pretty – they have been forced to bloom – and there’s not a bug on them. But the native coneflowers will have bees buzzing and other insects around them. Those plants have co-evolved as part of the ecosystem.”
The idea of attracting bees and insects to our plants is somewhat contrary to our notions of how to plan our gardens. Yet these creatures are the most important part of creating a wildlife habitat.
“They are the bottom line of the food chain for most species,” Smart says.
Plants and animals have adapted to live together. The insects that feed on native plants are a protein-rich food source, providing life-giving energy to creatures such as birds and box turtles. Most exotic plants simply do not have what it takes to nurture wildlife native to our area.
As we’ve bulldozed habitat and planted lawns of exotic grass and shrubs, most of us have simply expected native wildlife to find new homes. Yet Tallamy cites a shocking figure in his book: More than 70 percent of the forests along the U.S. eastern seaboard are already gone. This loss of habitat will never be replaced, so now it’s up to us – the suburban and even urban gardeners – to help give native wildlife spots to dine, raise their young, hide from predators and simply live.
But it’s just not practical or even desirable for most of us to suddenly switch out our non-native plants for natives all at once. Taking the first step involves simply identifying which plants are native and non-native in your garden.
“Go slow,” Hahn advises. “If there are animals using your non-native plants for shelter, you don’t want to just tear it out. But you might want to replace it with a native of similar structure.”
Another option is to set aside a particular area of your garden to begin your wildlife-centered plantings. Perhaps you could swap a section of grass for trees or shrubs.
A single oak tree can support 400 to 500 kinds of insects. Compare that to a manicured lawn, which supports very few.
When the time comes to plant, here are some natives to consider, recommended by the staff at Prairie ridge:
• Lindera benzoin, also known as spicebush, has yellow aromatic flowers and red berries that are favorites of insects, including the swallowtail butterfly and silkmoth.
• Viburnum prunifolium, or blackhaw viburnum, is a low-maintenance yet showy shrub that grows like a small tree and features clusters of white flowers that attract butterflies and birds.
• Callicarpa americana, or beautyberry, is a low-growing shrub with iridescent purple berries that fall in clusters and are a favorite of birds (also deer).
• Lobelia cardinalis, also known as cardinal flower, has showy red tube-like flowers and was named for the red robes worn by Catholic cardinals. The plant is particularly attractive to hummingbirds.