By Eric Mousel, South Dakota State University
A little extra rain this fall and cooler temperatures have stimulated many cool-season pastures with smooth bromegrass, Kentucky bluegrass, wheatgrasses and needlegrasses to provide some extra growth compared to the past several years. Extra fall regrowth is always welcome but as we move towards the end of the growing season, try to avoid grazing off every green blade.
Although it is tempting to keep livestock on these nice green pastures as long as possible, grasses need the opportunity to rejuvenate their energy reserves and root systems in the fall to allow for vigorous growth next spring. Grazing off a little regrowth just before winter could cost you a lot of spring growth next year.
To help pastures reach their growth potential for next year, be sure to leave at least 2 to 4 inches of green leaves if you live in Western ranges and 4 to 6 inches of green leaves in pastures in the Midwest at least two to three weeks before the average date for the first killing frost of the season. Typically, a killing frost is considered to be 3 successive nights of less than 20º F. Temperatures like this will ensure complete perennial vegetation dormancy.
These remaining leaves will allow the plant to continue photosynthesizing, producing energy needed for root growth and nutrient storage. Having a healthy reserve of stored energy will help vegetation avoid winter kill. Next spring, these reserves will be used by the plant to establish the first flush of green growth before the plant is able to start photosynthesizing on its own.
Leaving a little grass on your pastures this fall will put more grass in pastures next spring.