Cool-season perennial grasses produce vegetative tillers each growing season during mid-August to mid-October, says Lee Manske, North Dakota State University Dickinson Research Extension Center research professor.

These fall tillers will be part of the plant community for the next two growing seasons because all grass tillers have a two-year life span. During the first season, the tillers remain vegetative and just produce leaves. During the second season, the tillers produce a seed head and are terminated at the end of the growing season.

Development of vegetative tillers is the dominant mechanism by which grass plants perpetuate subsequent generations and maintain herbage production. Few grass plants develop from seedlings.

Normally, the fall tillers reach a height of 3 to 4 inches before a hard frost. However, as a result of the current favorable conditions, this year’s fall tillers have grown to an unprecedented 9 to 12 inches tall and have produced considerable herbage.

“Unfortunately, these fall tillers are not the extra end-of-season bonus feed source that they may appear to be,” Manske says. “Unlike mature lead tillers, young tillers cannot tolerate the removal of 50 percent of the leaf material. Young tillers can handle, at the most, the removal of 25 to 33 percent of the leaf material. Removal of more leaf material from this season’s fall tillers will reduce the grass density and forage production in your pastures during the next two grazing seasons.”

Grass plants managed by traditional grazing practices initiate vegetative tillers only during the late season. Grass plants managed with biologically effective strategies initiate vegetative tillers during the spring, summer and fall.

Tiller production will be part of the discussion at the next grazing management workshop scheduled for Jan. 6-8, 2015, at the Dickinson REC. To register, call Manske at (701) 456-1118 or email llewellyn.manske@ndsu.edu.