After clipping pastures throughout the growing season and managing pasture rotations to insure that plants are not overgrazed and that there is enough rest period between grazing passes, it can be tempting in the fall to let grazing management slide. There is fall crop harvest and any number of other fall tasks to get done before winter. However, from a plant health standpoint, overgrazing during the fall is more detrimental to the plant compared to overgrazing followed by rest in the early part of the growing season. Fall is the time when the perennial plant must store up carbohydrate reserves that will be used to survive the winter and generate new growth next spring.
In the fall of the year environmental conditions are not favorable for rapid leaf growth and an overgrazed plant will not be able to generate a lot of new leaf growth. Although leaf growth is slow, if sufficient leaf area is maintained throughout the fall season, photosynthesis is not slowed down. Physiologically this means that the carbohydrates produced by photosynthesis during this time period accumulate in plant storage organs. This is exactly what the plant needs to survive the winter and produce new growth next spring.
Once we reach the fall period it is critical that grass plants be managed to insure that adequate leaf area is left after a grazing pass. Since leaf regrowth is slow, this means leaving a typical grazing residual plus some extra. For orchardgrass, leave 4 to 5 inches at a minimum. Tall fescue and bluegrass should be managed to leave a 3 to 4 inch residual. If there is not enough pasture growth to allow the rotation to be managed in this way, then consider feeding some hay. Think of hay use at this time as another management tool that allows you to protect your pastures. You will be rewarded with quicker pasture green up and more vigorous growth next spring.