Carpeting the Roadside

It’s a sunny summer’s day, and you’re taking a leisurely drive on a scenic Bay Country byway. Dotting the roadside are native Maryland meadows, alive with the waving of tall grasses and a jolly mashup of brightly hued wildflowers. There are the lavender-blue daisy-like aster, the bright yellow plumes of the goldenrod and the starry pink crowns of milkweed.
    Such a sight could become more common along Maryland highways, thanks to the combined efforts of the State Highway Administration and the University of Maryland’s Bee Lab, which are teaming up on a field study to learn how to create roadside meadows that will be magnets for the state’s 430 species of bees as well as butterflies and other pollinators. The Highway Administration is a major real estate holder, maintaining more than 10,000 miles of roadsides, so the findings could have important implications for creating pollinator habitat throughout the state.
    Leading field research, which began in April, is Ph.D. student Lisa Kuder.
    “The study will compare two different cost-effective ways of managing roadside vegetation at seven test sites,” she explains.
    One method is reduced mowing, which allows meadow plants, including tall grasses and wildflowers, to re-establish themselves. Test sites will be mowed only once a year, in the late fall.
    “We hope to see native plants like milkweeds, goldenrods and asters coming back soon and flourishing again,” Kuder says.
    The other method, integrated vegetation management, involves no mowing. Vegetation is monitored, and spot treatment is undertaken to remove undesirable species, such as woody plants and trees, noxious weeds and exotic species. Warm season grasses and native wildflowers are encouraged. Some non-native flowers are permitted if they are beneficial for pollinators.
    “A potential advantage is that, by avoiding an annual, late-fall mow, it does not interfere with some late-breeding butterfly species or destroy birds’ nests and other creatures living in the tall meadow grasses,” Kuder says.
    The research will continue for three years, with biweekly samplings of vegetation and pollinators.
    “The full benefits become more apparent over time and will improve each year, so it is important to have a multi-year study,” Kuder says.
    For the Highway Administration, the primary concern in roadside vegetation management is safety and maintaining sight lines.
    “It’s a balancing act,” says Landscape Operations’ Pam Milby. “We’re looking at opportunities to create pollinator habitat where it’s appropriate and safe for commuters and wildlife.”
    Nationwide there are some 10 million acres of roadsides and 11 million acres of utility rights of way, which could be maintained in ways that promote bee- and butterfly-friendly habitat.
    “The study could also benefit other states working toward the same goal,” Kuder says. “There’s not a lot of data yet, and having more would be helpful.”
    Some conclusions have come early.
    Kuder has already learned that, she says, “Communities take a lot of pride in how their roadsides look and have a lot of say in how they want them to look. It’s important to engage with them and let them know what’s going on.”
    Already, she says, “everyone is pitching in to help our pollinators. Collectively we can accomplish a lot and make a difference.”