As warmer weather begins to take root, so too will noxious weeds that could damage transportation infrastructure and potentially reduce roadway visibility. That’s why Kentucky Transportation Cabinet highway crews are deploying spray trucks and other equipment as part of its annual campaign to control weeds along state-maintained roadways.
[Above photo by KYTC]
“There’s a lot more than paving when it comes to road work,” said KYTC Secretary Jim Gray in a statement. “Controlling noxious plants is a key part of maintaining safe roads as they can damage drainage systems; some can reduce visibility, while others attract wildlife closer to our roads and create additional dangers for Kentucky drivers.”
He noted that state residents treating noxious weeds on private property adjacent to state-owned rights of way may request the help of KYTC highway crews to control such vegetation.
Noxious weeds like Spotted Knapweed and Canada Thistle often invade and destroy the roadside turf grass, KYTC said; leaving these areas vulnerable to erosion. Aggressive invasive species like Kudzu can smother native plants through rapid reproduction and long-term persistence, while others like Amur Honeysuckle (a favorite of white-tail deer), if left to mature, can grow over 20 feet tall and wide – reducing roadway visibility while attracting wildlife dangerously close to roadways.
State departments of transportation use a variety of methods to boost roadside vegetation environments as well as control the growth of invasive plants in roadside ecosystems.
For example, a 2024 blog post detailed the critical roadside vegetation management work conducted by “agronomists” at the Alabama Department of Transportation.
An “agronomist” is a scientist specializing in the study and care of crops and plants, conducting research to improve growth, production quality, and to combat diseases. In the agricultural sector, they often act as liaisons between farmers and researchers.
When it comes to roadside vegetation management, Alabama DOT’s agronomists develop guidelines for mowing operations and the use of herbicides. They also develop policies to support pollinators and wildlife in and around the state’s road network; experimenting with different management practices to create habitats beneficial to all wildlife.
Meanwhile, a 2023 study conducted by the University of Minnesota and funded by the Minnesota Local Road Research Board determined that roadside plantings, particularly “turfgrass,” tend to do better when they are both biodiverse and carefully matched to their ideal growing conditions.
University researchers noted in a blog post that roadside turfgrass serves the important roles of reducing soil erosion, pollutant runoff, and the spread of invasive weeds, as well as adding visual appeal. However, maintaining it along Minnesota roadsides is difficult because of the harsh climate and roadway maintenance practices, such as road salting and snow plowing in the winter.
And the Illinois Department of Transportation recounted in a November 2022 blog post how it changed its mowing practices over the years to better protect roadside landscapes that are vital to pollinators and native planet life.
The agency said it adopted mowing policies to protect the habitat and migratory patterns of the monarch butterfly and other pollinators that use it as a food source. That policy allows for mowing of the state’s roads in a four-year rotation during the summer.
Meanwhile, ecologists at Idaho State University are working with the Idaho Transportation Department to turn state roadsides into veritable “Swiss army knives” of vegetation so they are both more fire-resistant and more welcoming to pollinating insects.
Those ecologists are working with three different types of ecosystems at those sites, figuring out how to make the land more hospitable to native plants and less so for invasive weeds. That research also includes increasing the habitat’s fire resistance, while becoming a more attractive habitat for pollinators like bees and butterflies.
