An article in a recent University of Kentucky forage newsletter shed some light on why orchardgrass hay fields no longer seem to be persisting as they did in the past. According to a survey of forage specialists across the U.S., the number one reason for shorter stand life was low cutting heights.
Low cutting heights were mainly attributable to disc mowers primarily because these mowers allow cutting heights of 1 to 2 inches. Low cutting heights are harmful to orchardgrass because all the leaves needed for photosynthesis and the base of tillers (stems) where carbohydrates are stored for regrowth are removed.
A research experiment on orchardgrass cutting height at the University of Kentucky found that just one season with low cutting heights significantly reduced stand longevity and increased weed infestation, regardless of the addition of fertilizer treatments. The results prove that the recommended cutting height of 3 to 4 inches for orchardgrass and similar grasses is essential to maintain thick, weed free stands.
Source:osu.edu