By Eric Jones and Graig Reicks et.al
After June 15 or July 10(dependent on location), right-of-way ditches can be mowed and/or hayed as announced by the South Dakota Department of Transportation. While there is a demand for grass hay, care should be taken when haying right-of-way ditches. Noxious weeds can grow within these areas and should be avoided to minimize hay contamination and the spread of seeds across the landscape (Figure 1).
While mowing can be a viable tactic to manage noxious weeds, cutting plants with seeds should be avoided to minimize agitation to the plant that can cause seed dispersal (Figure 2).
Source : sdstate.edu