Manage Interseeded Winter Annual Grasses Now to Limit Damage to Warm Season Grass Production
Paul Beck, Oklahoma State University, Extension Beef Cattle Nutrition Specialist
 
Interseeding cool season annual grasses like wheat, rye and ryegrass into bermudgrass pastures is a common way to extend the grazing season and provide high quality pasture when cattle need it most. By doing this producers are able to graze these pastures for 9 or 10 months instead of the 4 to 5 months of grazing we normally expect from pastures containing only warm-season grasses. Most of the benefit comes during the late winter and early spring when the cool-season annuals begin to rapidly grow through late February through early June. There are several issues with this production system that can cause big problems if they are not controlled.
 
Everybody that has ever grown a garden knows that bermudagrass and crabgrass are very hardy plants and difficult to kill. One of the sure fire ways to kill bermudagrass is to shade or smother it out. We can easily do this in pastures or hay meadows with our cool-season annuals if we are not careful. If allowed to grow uncontrolled late into the spring when warm-season grasses are breaking dormancy the cool-season grasses will outcompete the warm-season grasses for sunlight and nutrients. This will delay the growth of the warm-season grass or in severe cases reduce stand vigor or thin out warm-season pastures.
 
One way to reduce this problem is to only plant the number of acres we can graze during the spring, but that would require limit grazing or limiting the use of the cool-season forages in some way until spring growth occurs.
 
If we plant enough winter annuals to stock with our cattle in the fall and winter, then we may be able to adjust fertilizer levels to drive forage production for the times when we need more (fall) and put out less when we have more forage than we can use. Fertilizer is a good investment if we need or can use the additional forage it will produce; it is not worth its cost if the forage will not be used.
 
The best alternative may be to harvest the additional forage for hay or silage. If we have the equipment and are ready to roll when the time comes, wheat, rye, and ryegrass all make good hay and can be a valuable resource for wintering cattle later in the year.
 
Cool-season grasses can be a detriment to our warm-season pastures and hay meadows, delaying our first warm-season hay cutting or delaying summer grazing. But, with proper management these effects can be lessened and total forage production will be greater than if we managed for warm-season grasses alone.


Oklahoma State University, in compliance with Title VI and VII of the Civil Rights Act of 1964, Executive Order 11246 as amended, Title IX of the Education Amendments of 1972, Americans with Disabilities Act of 1990, and other federal laws and regulations, does not discriminate on the basis of race, color, national origin, sex, age, religion, disability, or status as a veteran in any of its policies, practices or procedures. This includes but is not limited to admissions, employment, financial aid, and educational services.  References within this publication to any specific commercial product, process, or service by trade name, trademark, service mark, manufacturer, or otherwise does not constitute or imply endorsement by Oklahoma Cooperative Extension Service.