Therefore, most of the extra energy derived from a November application of nitrogen is stored by the plant. Next spring, these storage products are used in green-up of the plant and more importantly, for root growth. According to some our earlier research, it is important for the plant to take up the nitrogen quickly in the fall and store the energy for maximum root growth next spring with a minimum of shoot growth. A spring application of nitrogen will never compensate for a missed application in November. Unmowed grass going into the winter may slump over and mat down creating the perfect environment for a disease called snow mold.
Snow mold can cause considerable damage to cool season turfgrasses during the winter.
This should be avoided because photosynthesis will continue until the plant is dormant, even in spite of cool temperatures. Photosynthesis at this time of the year allows the plant to store energy for winter and next spring, which is crucial for its survival. Scalping off grass leaves now reduces the photosynthetic capacity of the plant, reducing energy storage, and decreasing turf survival this winter and performance next summer. Additionally, regular mowing into the late fall will help mulch tree leaves into the turf. A layer of tree leaves will shade the grass minimizing photosynthesis and possibly smothering the grass.