A century-and-a-half after Confederate troops fought Union soldiers in a bloody campaign to preserve the Southern agrarian lifestyle, a war of another sorts rages at the Stones River National Battlefield in Murfreesboro. Park ranger and plant ecologist Terri Hogan marshals her troops, a small corps of rangers and volunteers, in a determined battle against invaders on native soil. Their enemy is not the blue-uniformed infantry of the North, but the green, lush shoots of invasive exotic plants: garlic mustard, Chinese privet, musk thistle and other non-native botanical marauders that threaten the delicate balance of biodiversity in Middle Tennessee. “Our job is to preserve both the natural and cultural history of the battlefield,” Hogan says. “That means protecting the local biodiversity for future generations.”
Invasive exotic plants threaten regional ecosystems when they are introduced in hospitable climates that are void of the plants’ natural predators. Without natural checks and balances, invasives like kudzu, vinca and Bradford pear can out-compete native species, such as the endangered Tennessee coneflower, ultimately affecting insects and wildlife dependent on indigenous flora for food and habitat. Without efforts to curb invasives, Hogan says, “we’re handing our children a much-depleted environment.”
On one side of the Old Nashville Highway in Murfreesboro, thousands of soldiers lie interred beneath the alabaster headstones of the Union cemetery. Across the road, newly slain carcasses of bush honeysuckle sprawl across the floor of a cedar woodland. Hogan, uniformed in the green-and-brown regalia of the National Park Service, surveys the woody carnage of winter’s campaign to clear the invasive shrubs.
In 1862, when the Battle of Murfreesboro, as the Confederacy called the Battle of Stones River, raged across 4,000 acres of Rutherford County, hogs and cattle most likely roamed this wooded section. When the war ended, the land was developed into a subdivision known as Cemetery, and homes were built for the freed slaves. That’s when the privet, honeysuckle and other invasive exotic species were probably introduced as landscaping plants. “Land-use patterns change, and we’re constantly speculating about what happened,” Hogan explains. Around 1930, the National Park Service acquired the Cemetery subdivision and razed the houses. With neither the natural predators of their native soils nor the gardening discipline of homeowners, various non-indigenous landscaping and food crops grew unchecked across the cedar grove.
Today, Hogan brandishes an 8-by-10 color photograph of a Northeastern forest quilted with garlic mustard, the same species popping up across the across the floor of the cedar woodland where she stands. To the ecologically untutored eye, the photo of white flowerets and green leaves could make a nice cover for a Sierra Club calendar. But to Hogan, as well as to fellow ranger Kyle Hurt and volunteer Keith Shaver, so much garlic mustard is “horrifying,” and they are hell-bent on rooting it out.
“Yep, we’re weeding the forest,” says Shaver, kneeling on the ground and digging out the edible mustard, root by root, with his Rambo knife. Shaver volunteers at the park once a week. Some days it’s garlic mustard he’s after; other days it’s privet. Or honeysuckle. He and Hurt laugh about the focus required to home in on garlic mustard one tuft at a time across the forest floor when there’s still so much privet dotting the ground. But they are resolute, ignoring the shoots of privet today. They will tackle them another time. The list of priorities for eradicating exotic invasives is long; the time frame is years. Invasive plant management is not for people with short attention spans.
A Pennsylvania Yankee here on sacred Southern soil, Hogan harbors only a modest interest in the military past of the battleground she is charged to protect. She and her team employ military metaphors—like “standing their ground” against “foreign invaders”—without seeming to register the contrast between the bloody slaughter of war and the patient gardening of plant management, two disparate chapters in the battlefield’s history. Hogan is focused on the future of the land’s ecology. As she passes relics of abandoned artillery, she gestures casually toward the decrepit cannons. But a few yards farther along, on the border of a meadow of Indian grass and broomsedge, she speaks with near-solemn reverence: “It’s just so beautiful,” she says, pulling a single golden sheaf from the waving meadow. Her delight is tempered only by the sight of a housing development rising at the back of the field. (While exotic invasives are the number-two cause of rarity in plant species, loss of habitat is the greatest threat.) In the four years since she came to Stones River, Hogan has also worked to restore the native Tennessee grasses to how they might have looked circa 1862. “Once you remove exotic invasives,” she says, “you need to get natives in. Competition from the natives helps.”
As invasive exotics have become an increasing threat over the last 30 to 40 years, groups like the Tennessee Exotic Pest Plant Council, founded in 1994, have formed to stem existing infestations and prevent additional species from infiltrating local areas. By educating homeowners about the environmental risks of landscaping with invasive exotics, the state and regional EEPCs and wildlife agencies hope to reduce consumer demand for common invasive exotics—seemingly benign plants like winter creeper, English ivy and nandina—and ultimately drive big-box retailers like Home Depot and Lowe’s to stop carrying them and plant nurseries to stop growing them. In the meantime, many parks and natural areas are relying heavily on volunteers to root out manually the persistent weeds and plant native species that can repopulate the infested areas.
Andy Sudbrock is building a business out of propagating and popularizing native species. His nursery, Nashville Natives, lies on a hill in Fairview, where Sudbrock has restored a prairie by burning off the fescue and Japanese honeysuckle to reinvigorate the strangled native grasses. Now, broomsedge and other natives mirror the natural scene at Stones River. As the grasses have returned, so have the bobwhite quail, Sudbrock adds. “When you think about a whole landscape, you need the diversity because it leads to diversity of plants and animals.”
Every piece of Sudbrock’s naturalized landscape is thoughtfully managed to nurture indigenous plant life in an organic environment. He has laid out various demonstration gardens—so naturally integrated into the landscape that they hardly seem like gardens—that showcase the broad variety of local species. A small cedar glade occupies the center of the driveway, where five or six endangered species grow, including Tennessee coneflowers. A few feet from the rocky glade, in a lower, waterlogged micro-habitat, a rain garden of native species captures the silt from the hillside run-off, purifying the water before it reaches the creek below. Every species visible is native to Middle Tennessee. Soon a woodland path beside the nursery office will be alive with ephemeral wildflowers.
The greenhouse is lined with native plants, from seedlings to 2-year-olds: tiny birdsfoot violet, bloodroot, spring beauty, trillium and bluebells. Sudbrock helps with the invasive eradication programs in various local parks, similar to the efforts at Stones River. He has permission to harvest plants that are otherwise off-limits to park visitors in order to propagate them. He is currently cultivating a blazing star harvested from Beaman Park, and will ultimately replant the seedlings in the park to foster the natives there.
For Sudbrock, biodiversity and beauty go hand in hand. “I hate mowed grass,” he says. “I’d rather look out my window and see a bunch of beautiful birds, grasses and butterflies…. There’s just so many reasons to use native plants. They’re Mother Nature-approved. If you put the right plants in the right places, you can’t go wrong.”
Nashville Natives is located at a 7443 Liberty Road, Fairview, 799-8719.
For more information about volunteer invasive plant removal programs in Tennessee state parks and natural areas, including Radnor Lake, call (888) 867-2757. For information about volunteer programs in Metro parks, contact the Warner Parks Nature Center at 352-6299.