– William S. Curran, Professor of Weed Science, Penn State University

At the recent Ag Progress Days in Pennsylvania one of the most common questions asked involved perennial weed control in grass hay and pasture. While we still have nice warm days, it is good time to scout pasture and hay fields for the presence of perennial weeds. As you hopefully have heard before, late summer and fall is the best time to control most perennials with a systemic herbicide because herbicides are moved into the root systems allowing more permanent control. With the autumn weather, these plants more actively transport carbohydrates and sugars to underground storage structures such as rhizomes, tubers, and roots to enable them to survive the winter and to provide the necessary energy to begin the next cycle of growth in the spring. Mowing the pasture and hay fields in mid-summer or several weeks before the herbicide application to prevent seed production and to promote healthy new leaf tissue that can intercept the herbicide is also important. In general, the application window runs from Continue reading →