As soon as the weather cooperates, the Pittsburgh Botanic Garden is planning to burn its beloved dogwood meadow. According to local experts, it’s the first time a conservation organization has utilized prescribed fire in Allegheny County in decades, perhaps ever.
And it’s a good thing.
A prescribed fire, also known as a controlled burn, is the deliberate use of fire to manage habitat. In the Eastern United States, fire has long been a tool of land stewards in the longleaf pine savannas of the Southeast; in the pine barrens of southern New Jersey; and in the tallgrass prairies of Illinois, Indiana, and Ohio. These systems evolved with fire, and their health depends upon this ecological disturbance—fire-evolved systems require flames like wetlands require water.
In southwestern Pennsylvania, however, fire is still an emergent management tool; in Allegheny County, it is nonexistent. The Pennsylvania Game Commission, the leading practitioner of prescribed fire in the state, said they have never conducted a burn in the county.
But this frequency of fire may soon begin to change.
The Dogwood Meadow
The Margaret Lawrence Simon Dogwood Meadow is one of the Pittsburgh Botanic Garden’s signature landscapes. A popular backdrop for wedding photos, and a favorite for family hikes, it is bathed in sunlight and blanketed in wildflowers.
Ecologically, the meadow is managed in a state of arrested succession. For the past century, this spread of land had been variously farmed, grazed, and hayed. When the Botanic Garden took over the site in 1998, it was a riot of fall colors, with the bright yellow blooms of goldenrod and the purples of flowering asters; under the Garden’s stewardship, it buzzed with native bees and the songs of grassland-loving birds; great-spangled fritillaries and monarch butterflies flitted over the site. And it was ringed with a stunning collection of more than 500 mature dogwood trees (Cornus florida)—thought to be one of the largest collections of naturally-occurring, open-grown flowering dogwoods anywhere.
It is a special place.
Without frequent disturbance, however, the meadow and its associated species will vanish. This is not unusual—ecological conditions in southwestern Pennsylvania almost always drive the land to forest—but it was not preferred. PBG liked the idea of having this early-successional habitat type—for educational purposes, for the sake of the wildlife and songbirds that thrive in open areas, and because it was beautiful.
Thus far, they’ve managed to resist the encroaching forest by mowing once every three years. But a few years ago, a new problem emerged that was different than the encroaching forest—Lespedeza cuneata, a pernicious, invasive exotic, suddenly appeared in the Garden, and in 2023, it was found growing in the meadow. Mowing would continue to keep the trees at bay, but it would do nothing to stop the spread of Lespedeza cuneata.
Lespedeza cuneata, also known as sericea lespedeza, did not evolve in community with the indigenous plants of this dogwood meadow, and it was rapidly outcompeting the native wildflowers and grasses. “Once established, sericea lespedeza typically grows taller than competing native plants and tends to have a dense, branching aerial structure that can prevent sunlight from reaching understory plants,” a team of Kansas researchers reported in 2021. Purdue University has called this bush clover the “Plague on the Prairie.”
PBG believes the species was erroneously introduced to another area of the property in a post-mining seed mix. Before long, seeds found their way to the sunny, open areas of the dogwood meadow. If it wasn’t managed soon, the species would continue spreading throughout the Garden, resulting in a loss of native biodiversity and a setback to decades of restoration.
In the fall of 2023, Alexis Balog, then a PBG intern, was tasked with investigating solutions for the budding threat. They could spray herbicides, of course, but the Garden prefers to reach for conventional herbicides only as a last resort. Another route? Spray the plants with horticultural vinegar, and follow that with something unheard of in Allegheny County: a controlled burn.
Changing views on fire
Many Americans fear fire, and for good reason. Pittsburgh’s Great Fire of 1845, in which a third of the city was destroyed, might not be top of mind for most county residents, but devastating fires linger in our cultural memory. In recent years, the Northeast has been beset with numerous wildfires burning amidst our record droughts, and foresters and firefighters have lost their lives battling flames on wild lands from West Virginia to New York.
But the historic wildfires of Pennsylvania were typically far less dangerous. The kinds of fires that were common here for hundreds and thousands of years were more frequent, slow-moving, and of low intensity.
According to Lauren Howard, a plant community ecologist at Arcadia University who specializes in the fire ecology of central Appalachia, fire would have come through the oak and pine forests of western Pennsylvania every ten years or so.
“The forest was burning at least that often,” Howard said. “And I’m not talking about a canopy fire like you see on TV from California, this would be like burning along the surface of the ground.”
These historic fires were caused by lightning strikes, but more often than not, they were the deliberate work of Indigenous people who burned both meadows and forests to improve the hunting of game. Fire not only cleared the landscape of thick brush, it also maintained the early-successional plant communities that attracted species like whitetail deer, eastern elk, and wild turkey. Fire made it easier to hunt, and the game more abundant.
Fires set by Native Americans also reduced fuel loads in a landscape, which lowered the risk of a catastrophic wildfire destroying a town or village—this was true hundreds of years ago, and remains so today.
Burning the Forest to Protect One of its Most Threatened Visitors
A century of absence
For the past hundred years, Pennsylvania foresters and private landowners have sought to suppress all fire—in the early 20th century, wildfires were often the result of industrial carelessness, and the state’s cut-over timberlands burned with an intensity that caused more harm than good.
But as the science of fire ecology has grown, and as the professional practice of prescribed burning has developed, controlled burns have made inroads in southwestern Pennsylvania. Land managers and ecologists now realize that not all fire is bad. And in the contemporary landscape, fire offers another service: it can be a tool for the job of invasive species management.
In 2009, the Pennsylvania legislature passed the Prescribed Burning Practices Act, which “recognizes the value of prescribed burning and protects those who implement prescribed fire when following certain standards,” according to Penn State University.
Over the past 15 years, thanks to the work of the Pennsylvania Prescribed Fire Council and the Pennsylvania Game Commission, the number of controlled burns in the state has risen steadily; during the burn seasons of 2023-2024, the Game Commission burned more than 11,000 acres of forest and grassland. Prescribed fires have been conducted on state parks, National Park Service sites, and on state game lands in Washington, Butler, Fayette, and Greene counties. And this past May, the Game Commission conducted a helicopter-ignited fire at State Game Lands 108, in Blair and Cambria counties, which burned over 2,271 acres—the largest prescribed fire in state history.
In most cases, the reason for this increased use of fire is the same as it has been for millennia: to improve the hunting, and the habitat, of game species. But fire is also good for a number of other species, like the near-threatened golden-winged warbler (Ermivora chrysoptera), and the state-endangered eastern massasauga rattlesnake (Sistrurus catenatus), both of which require open grasslands and the early-successional habitats that fire supports.
Fire in the Garden
A western Pennsylvania native, Alexis Balog, who now works for the Garden, earned a master’s in plant biology and conservation from Northwestern University in Chicago. Working closely with the Illinois conservation community, she was exposed to the prescribed fires that are routinely implemented in the state’s tallgrass prairies. As a result, it felt natural to suggest burning as a management option at the Garden.
When the decision was announced at the local Invasive Species Communications Roundtable, hosted at the Carnegie Museum of Natural History, the assembled group broke into a spontaneous round of applause. “There was a lot of enthusiastic response,” Balog said, “which also helped push us to really try and make it happen.”
Sue Myers is director of horticulture and conservation at the Garden. When she was presented with the plan, her immediate thought was the potential for collaboration with other conservation groups in the region. “We’re mostly excited about sharing it with other people,” said Myers. “Because I think that’s really how we’re going to multiply our efforts out into a wider community.”
Since there aren’t many fire practitioners in the immediate region (the overwhelming majority of prescribed fires in SWPA are conducted by the Game Commission and the Department of Conservation and Natural Resources), the Garden contracted with the West Virginia-based land management company, Nature Works LLC. They had hoped to burn the dogwood meadow last fall, but there was too much rain, and not enough brown plant material, for a hot, effective fire. PBG is documenting their process and sharing lessons learned with local conservationists, dubbing the program a “Learn & Burn.”
The fire in the dogwood meadow, which is around four acres, will be tiny compared to those recently conducted on state game lands; rather than aerial ignition, it will be lit by conventional drip torches. A second controlled burn will also be conducted in the Exhibit Garden, where Lespedeza cuneata has also been discovered.
Nature Works’ founder, James Remuzzi, says fire has always been with us, “but it’s been excluded largely for the last 150 years.” And he acknowledges that reintroducing this ecological force is no easy task anywhere.
“It takes real leadership to be like, ‘We’re going to do this thing that’s inherently risky,” even though it has massive benefits,” Remuzzi said.
Even fire has its limits
While fire is a natural and historic disturbance, it’s not a magic wand. Some research indicates that fire might actually benefit Lespedeza cuneata, as the germination of its seeds appears to benefit from prescribed burns, according to the Missouri Department of Conservation. “However, burning can be beneficial at getting sericea seeds stockpiled in the soil to germinate by other means,” the Department reports, “and September burns can be effective at aiding control in combination with other controls.”
Whether fire and horticultural vinegar will be enough to control PBG’s lespedeza problem is yet to be seen. One land manager I spoke to says it might take 20 years to get a handle on Lespedeza cuneata once it’s well established. According to some estimates, its seeds can remain viable for a century.
But perhaps more significant than how this single species responds to fire is the milestone: the return of fire to Allegheny County’s natural lands.
Caitlin McCalla, vice president of stewardship at Allegheny Land Trust, is participating in the Learn and Burn. McCalla is responsible for managing invasive species on about 1,500 acres of land trust properties.
“There have been restoration projects that we would have preferred to be able to do a burn, and without that option, we had to utilize herbicide,” McCalla said. Confronted with the barriers to implementing a prescribed fire in Allegheny County, “I just completely ruled it out as an option for management.”
If the Garden’s burn is successful, however, those barriers may no longer seem so insurmountable.
For Sue Myers, this prescribed fire, and this sharing of knowledge, represents the future of the Pittsburgh Botanic Garden.
“Traditional botanic gardens have this reputation of being a place where you can go and you can see plants from all over the world,” she said, “[and] we really want to go beyond pretty, we want to go back to that idea of resilience, and health, and interdependence… [and] being a scientific institution that is doing this really important work, that’s coming at a really important time when it’s needed.”
“We’re really hoping to show people that nature is resilient,” Myers said, “and that we can be part of that.”
In the meantime, Myers is also hoping for good weather—not too wet, and not too humid—so that the grasses will ignite, and the fire will carry.
