While visiting some grass hay fields across the state I have encountered several fields where cutting height was too low. While we all want to get the maximum yield possible from our fields, cutting too low can have negative impacts. Disk mowers allow the crop to be cut very close to the ground, in some cases almost cut to the ground level. While older haybines or sickle bar mowers require some stubble height to remain. Many may not realize that cutting height has an impact on forage stand longevity. Cutting too low reduces the energy reserves of the crop vital to regrowth for the next cutting. The energy reserves of grasses are stored above ground in the base of the stem and tillers, Continual cutting of grass hay close to ground level will result in depletion of energy reserves which in turn reduces stand longevity. So, the question most often asked is how low can I cut my grass hay while maintaining stand longevity? For our cool season grasses such as orchard grass and timothy we manage the cutting height different for establishment and production years. For the establishment year it is recommended to maintain a cutting height of 4 inches. During the following production years, a minimum cutting height of 3 inches is recommended. These heights are the minimum recommendations; it is certainly acceptable to cut higher. Cutting too much top growth in grasses removes growing points and reduces the amount of leaf exposed to the sun. This can result in slow regrowth, which indirectly results in a shortening of the growing season for the crop and reduced yield potential. Another benefit of cutting higher is reducing competition from weeds. Weakened or stressed grass results in reduced stand density which provides an opportunity for weeds to establish.