South Carolina has the fourth-largest, state-maintained highway system in the nation. For the South Carolina Department of Transportation (SCDOT), this translates to having its hands full when it comes to maintaining roads.
Much of this maintenance falls into the lap of the agency’s integrated roadside vegetation management coordinators. Ken Caldwell is the integrated roadside vegetation management coordinator for SCDOTs District 4, which covers several counties in the northern part of the state.
“My major job functions are coordinating all district vegetation management activities, including things like contract mowing, in-house mowing, mechanical brush and limb management and herbicide spraying,” Caldwell said. “My priorities are providing a safe roadway, maintaining adequate sight distances and controlling noxious and invasive weeds—all while maintaining aesthetically pleasing roadsides.”
And for many roadside managers, an aesthetically pleasing roadside starts with the presence of healthy grass.
Healthy grass provides beauty, erosion control and resistance to broadleaf weed invasion
“We have quite a few types of desirable grasses that grow in our district, because the soil type varies from red clay to deep sand,” Caldwell said. “The dominant grasses are Bahia grass, Bermuda grass and fescue, and while performing our maintenance duties, it is very important that we do not injure the turf that is in place.”
“The turf is what prevents erosion on the roadside, so we want to avoid creating bare ground areas when we treat,” Caldwell said. “Our district is full of rolling hills, and we have quite a bit of topography, which makes it very important for us to maintain healthy grass on all these slopes in order to keep our roads secure and safe.”
But erosion is not the only thing Caldwell wants to keep under wraps. Undesirable weeds and brush are top of mind, as well, as they can create safety issues on roadsides by blocking line of sight or traffic signs. Caldwell lists a couple of weed species that are especially troublesome, such as thistles and wild lettuce, but one rises to the top: kudzu. This brush species is so prevalent in Caldwell’s district that some cities and towns actually hold kudzu festivals every year to mockingly celebrate this extremely difficult-to-control plant species.
Recently, SCDOT has been trying to find a product that carries a “CAUTION” signal word on the label and is effective on kudzu and other prevalent broadleaf weeds. Milestone® specialty herbicide has gone through the SCDOT-required process to evaluate new materials with very good results.
“Milestone has proven to be a very effective tool in our herbicide toolbox,” Caldwell said. “It’s shown excellent results on kudzu, wild lettuce and thistles. By controlling these weeds, it gave our turf grass room to spread out and made our interstate highways look much better. And it had little or no adverse effect on the desirable grasses, so we have created a much better stand of desirable grass.”
Rogers is an IVM Market Development Specialist for Dow AgroSciences
Dow AgroSciences LLC