A year-long project led by the Kentucky Department of Fish and Wildlife Resources is using herbicide-spraying drones to control kudzu, the rapidly growing vine that has swallowed tens of thousands of acres of land. So far, it’s proven highly effective.
If you take a long country drive through almost any part of the eastern United States, you’ll eventually see an invasive plant known as “the vine that ate the South.”
From a distance, it appears to be a patch of healthy greenery. Up close, it reveals itself as a sprawling blanket of tangled leaves smothering nearly everything beneath it.
That vine is kudzu, and it’s spread across tens of thousands of acres since its introduction to the US more than a century ago. It was often utilized by ranchers for cattle feed, and by New Deal-era construction projects for erosion control.
Now, Kentucky wildlife officials are testing whether a new generation of drone technology could become one of their most effective tools for fighting back.
“For the foreseeable future, I see this as something that we'll definitely pursue and keep going with,” said Jacob Stewart, Private Lands Program coordinator for Kentucky Fish and Wildlife.
New tools for old problems
A year-long project led by the Kentucky Department of Fish and Wildlife Resources is examining whether herbicide-spraying drones can help landowners control kudzu on steep, hard-to-reach terrain and in remote areas of the state.
Last year, crews with the agency’s Private Lands Habitat Program treated 93 acres across eight sites in Clay, Estill, Jackson, Knox, Owsley, and Whitley counties. When biologists returned this spring, they found large sections of formerly dense kudzu reduced to scattered patches.
The project grew out of a simple question: if drones can spray crops or scatter seeds efficiently, could they also help manage invasive plants on rugged landscapes where traditional equipment struggles?
“It's just the idea of saying, ‘all right, let's take something that's been functionally used for this and try it on a different aspect,’” Stewart said. “Herbicide from the air on this steep stuff is better than trying to walk up with a backpack. Let's see how it works, and let's try.”
“We've seen [drone-treated properties] full of wildlife. Not only just native plants coming back up, but we're finding snakes, and we're finding chipmunks, and squirrels, and songbirds, and white-tailed deer, and turkey, and everything's in these sections and still utilizing these areas.”Kentucky Fish & Wildlife Private Lands Biologist Daniel Skinner
For wildlife managers, the appeal is obvious: a drone can treat terrain that would be difficult or dangerous to reach on foot. Stewart said a 26-acre site in Whitley County on a reclaimed coal mine site was sprayed in about an hour and a half, a task that could otherwise take days or even weeks.
In addition, that efficiency means less herbicide can be used overall, reducing the risk of chemicals leaching into waterways. It also lessens land managers’ exposure to chemicals used to combat kudzu and other invasive species.
Non-chemical treatments usually rely on heavy equipment like bulldozers, but transporting the equipment into remote areas can be costly. Steep terrain — which kudzu often thrives in — can also block heavy equipment from safely operating.
Cattle, goats, or pigs are sometimes used to control the sprawling vine, but Stewart says managing such an operation isn’t feasible for many landowners due to transportation costs, longer timeframes, and the risk of kudzu growing back from its roots.
But officials say the technology is about more than efficiency. The project is part of Kentucky Fish and Wildlife’s broader effort to work with private landowners, who collectively own most of the state’s land.
Through habitat plans, technical assistance and cost-share programs, the agency helps property owners meet their own goals while improving conditions for wildlife.
“The goals for any piece of property that we go to are led by the landowner and what they're looking to do,” Stewart said. “We're just here to give them the advice and walk them down the path of how to meet their objectives.”
That approach often means balancing economic realities with conservation goals. Stewart said most landowners want healthy wildlife populations, but they also need productive farms, forests or hunting properties.
“If you're willing to work with us, there are options to have wildlife and make money too as you go,” he said. “You don't have to pick one over the other.”
The program’s long-term vision extends beyond individual properties. Wildlife habitat, invasive species and land management practices rarely stop at fence lines.
The owner of a single plot of land can make countless changes to encourage native wildlife, but if inhospitable properties surround it, the impact will be limited.
“The puzzle of land ownership in the state of Kentucky is what drives wildlife use,” Stewart said. “If the pieces of the puzzle that make up the landscape support quail, you'll have quail. If those pieces of the puzzle of the landscape don't support quail, you won't have quail.”
That reality makes collaboration between neighbors especially important.
“The idea is landowners working with landowners and trying to come up with solutions to do stuff,” Stewart said.
Wildlife officials say the kudzu project also demonstrates how new technology can help address longstanding conservation challenges. Drones are already being explored for managing other invasive plants, mapping landscapes and even assisting with prescribed fire operations.
“The key with wildlife management is to try to figure out what tools are out there and then come up with a prescription that meets the needs of the landowner to get it done,” Stewart said.
Getting into the weeds
Still, using drones to control invasive species isn’t yet a widespread practice. Stewart said he’s unaware of any other states that have adopted herbicide-applying drones on a wide scale.
Biologists stress that invasive species control is rarely a one-time fix. Kudzu management can require multiple years of treatment and monitoring. Still, early results have been encouraging.
“We've seen [drone-treated properties] full of wildlife,” said Daniel Skinner, a private lands biologist involved with the project. “Not only just native plants coming back up, but we're finding snakes, and we're finding chipmunks, and squirrels, and songbirds, and white-tailed deer, and turkey, and everything's in these sections and still utilizing these areas.”
Stewart said the goal is not simply to eliminate one plant, but to reopen space in which a variety of native plants and wildlife can return to the landscape.
Milkweed, for example, has already returned to some of the areas where kudzu has been killed off. Monarch butterflies primarily rely on milkweed during annual migrations to Mexico, and the plant’s consistent decline in recent decades has subsequently hindered monarch populations.
“The key to anything good as far as wildlife goes is diversity of habitat,” he said. “All kudzu is one type of habitat. It may benefit something at some level, but the idea is getting something back to where you see different patches of shrubs, and grasses, and everything else starting to form and become a diverse landscape.”
For now, the next step is refining the process and making it accessible to more landowners through conservation programs and partnerships. Stewart said they’ll likely continue drone treatments for the next two years to create a prescriptive guide that landowners can reference when managing their own kudzu.
Officials hope the project will ultimately provide a blueprint for managing one of the South’s most notorious invasive plants.
“First thing, we wanted to see if this is effective,” Skinner said. “Now that we know that it is effective, let's start figuring out ways of getting this going, outreach with landowners, and start to get some of this put on the ground.”
