Too tall, too short, or just right? What is that “perfect height” to leave pastures going into winter? It can be useful to vary your pasture heights depending on how the paddocks will be used over the winter and in the spring.
We are defining a tightly grazed pasture as having a residual height of 3-4 inches after the final grazing pass in the fall. Why would you want to graze the pastures this low? Areas grazed to 3-4 inches tall will be slightly stunted in the spring compared to areas left taller. This can be an advantage if you are planning on frost seeding in February-March. This can also be a good height to interseed in in the fall. The shorter grass will work well to drill into and its slowed growth will allow extra time for the new seedlings to get up and growing in the spring. We do not recommend doing this to all of your pastures as it can cause some stress to the stand
A “medium” height pasture would have a height of 4-6 inches after grazing in the fall. This is the preferred height for most pastures going into winter. This leaves enough residual that the grass will not pull from all its reserves going into the winter. The ground will be sufficiently covered to go through the winter and it will have enough height for spring growth to be jump started. Plan on leaving pastures that will be grazed late spring to early summer at this medium height this fall.
We would call a pasture that has 6-8 inches of remaining stubble “tall.” After the final pass of grazing in the fall, we do not recommend many pastures be taller than this unless you are stockpiling certain paddocks. If an area is taller and is not grazed before snowfall, air can be sealed out and cause snow molds. Areas left at 6-8 inches can kick start their growth quickly in the spring providing your earliest grazable paddocks.
Every pasture and management system is different, but consider these various heights as you get through your last passes of grazing this fall.