Mowing Before or After an Herbicide Application Does Not Influence Ground Ivy (Glechoma hederacea) Control

Many turfgrass extension bulletins and herbicide labels recommend prolonging or suspending mowing practices 1 day or more before and/or after herbicide applications to increase efficacy. However, the effect of mowing timing on herbicide efficacy has not been sufficiently explored. Field experiments were conducted to evaluate the influence of herbicide selection and mowing timing relative to herbicide application on the control of ground ivy (Glechoma hederacea L.). The three mowing treatments included mowing 30 min before herbicide application, mowing 30 min after herbicide application, and not mowing for at least 7 days prior to and at least 3 days after herbicide application. Aminocyclopyrachlor resulted in the greatest reduction of ground ivy cover in 2011 and 2012. Like aminocyclopyrachlor, 2,4-D ester and metsulfuron reduced ground ivy cover both years, while triclopyr reduced ground ivy cover as well as aminocyclopyrachlor in 2012. Although 2,4-D + mecoprop (MCPP) + dicamba was not among the best performing herbicides, it reduced ground ivy cover compared with the untreated check in both years. There were no mowing or mowing-by-herbicide interactions on any of the rating dates. Thus, this research suggests that the timing of lawn mowing relative to herbicide application has little measurable impact on herbicide efficacy on ground ivy.