Native warm-season pastures infested with cool-season grasses will be more vigorous next summer if those species are removed, says Bruce Anderson, University of Nebraska Extension forage specialist.
He says cheatgrass, downy brome, bluegrass, smooth bromegrass and other cool-season plants have invaded many warm-season grass pastures and rangeland. That shifts good grazing away from summer and toward spring when most producers have plenty of pasture anyway.
Cool-season grasses take over summer pastures relatively easily because they develop rapidly during fall and spring when native grass provides little competition. Then they deplete moisture and nutrients during spring before warm-season plants have a chance to use them.
Hard grazing this fall after hard freezes as well as early next spring will weaken bromegrass and bluegrass when warm-season plants are dormant and unaffected, says Anderson. That can stop further invasion and slowly improve summer production. A prescribed spring burn also can do wonders for a warm-season pasture.
An even faster approach is to apply glyphosate in late fall. Spray when daytime temperatures are above 60° and nighttime temperatures stay above 40° for best results. The green and susceptible cool-season grasses will be killed or weakened, but dormant warm-season plants won’t be affected. By reducing competition, warm-season plants will grow more vigorously next year, providing better summer pasture.
“Don’t settle for invaded native pastures,” says Anderson. “Transform them back to vigorous warm-season grasses for better summer grazing.”