June 13, 2018
Recommendations for Reestablishing Crested Wheatgrass
A long, cold, icy winter in 2017-2018 was very harmful to crested wheat grass. Although snow amounts were record-setting in some locations around the state, crested wheatgrass died in areas where wind kept areas free of snow cover. Where crested plants had little residual stubble, the wind and cold temperatures killed the buds. In other areas, thick sheets of ice covered crested plants, and especially where residual stubble was limited, the ice exacerbated the cold temperatures and killed the buds. Below are some recommendations from Jeff Mosley (MSU Extension Range Management Specialist) on reestablishing grasses in these areas.
Eliminate weeds before seeding the crested wheatgrass or crested wheatgrass-legume mixture. Potentially, seeding could be accomplished this spring if sufficient soil moisture remains after the weeds are killed. In many cases, however, soil moisture and rainfall will be insufficient in spring by the time the yellow alyssum or other weeds have been killed and sufficient time has passed after herbicide application (see below). Usually it is best to plant a cereal grain for one year and then seed the perennial grass into the stubble of the cereal. The most popular cereal choices are forage varieties of barley (e.g., ‘Haybet’) or winter wheat (e.g., ‘Willow Creek’).
How soon after weed control can I seed?
Consult the label of the specific herbicide formulation used to control the weeds. In general, seeding should be delayed 2 to 3 months after Escort application (2 months if 0.5 to 1 ounce/acre was applied or 3 months if 1 to 2 ounces/acre was applied). The label for Roundup Ultra2 herbicide states that it can be applied immediately before, during, or after seeding but before seedling emergence. However, experience has taught me that it is best to wait 2 or 3 weeks after glyphosate application before seeding perennial grasses.
Should I seed in spring or late fall?
Seeds need to germinate in the spring when soil and air temperatures and soil moisture are optimal for plant growth. If seeding in the spring, producers should seed early enough in the year that the seedlings will have enough time to establish before it gets hot and dry. A common challenge is that fields are too wet to seed in the early spring, and by the time the field dries out enough to seed, hot summer weather is fast approaching. To avoid this problem, seeding can be done in late fall. Seeding needs to be delayed until it is cold enough that the seeds will not germinate until spring arrives. Seeding should not be delayed too long into late fall because seeding must occur before the soil has frozen. One big advantage of seeding in late fall is that the seed is in the ground and ready to go when optimal growing conditions arrive the following spring.
Montana State University U.S. Department of Agriculture and Montana Counties Cooperating. MSU Extension is an equal opportunity/affirmative action provider of educational outreach.