Broomsedge Management

DR. ANTHONY OHMES

JACKSON MISSOURI

Broomsedge (a.k.a broomsage, bromesedge, yellow bluestem) is a warm season perennial grass found throughout Missouri. Like other warm season grasses, it is dormant during the fall through early spring.  Broomsedge growth begins as temperatures consistently stay above 60 degrees F. It produces many seeds that are distributed by wind.  There is a very short palatability window when vegetative growth just begins, prior to early boot that cattle might graze broomsedge, but even then the low quality forage is generally avoided in a continuous grazing system.

I have received a number of calls regarding soil test results and broomsedge populations in pasture and hay fields.  Broomsedge typically is an indicator species for low pH and/or low phosphorus soils and can quickly become the dominant species under these conditions.  However, this is not always the case as to why broomsedge is dominant in a field, therefore, soil testing is the first step in management.  Broomsedge is not constricted to growing and thriving in only low pH/poor fertility conditions which can throw a forage producer off when their soil test results come back testing medium to high in pH and phosphorus.  Producers must also consider other factors to why the dominance has shifted away from a cool season perennial forage grass.  Broomsedge is a poor competitor and needs an open canopy where light can help with seed germination and growth.  It can quickly become the dominant species in over-grazed, thin (eroded) soil where desired forages have died and/or will not thrive, as well.  

Since broomsedge is a perennial and usually well-established when many consider managing, elimination within a single season is generally not practical.   Management over time will shift the competitive edge toward the desirable forages.  Management may include improving soil pH and fertility, if soil test indicates.  Mowing, if broomsedge is shading desirable species lower in the canopy, may improve light penetration to desirable forages.  However, neither mowing nor prescribed burning will reduce established broomsedge populations.  Evaluating pasture to determine if desired forage species are present.  If not present at sufficient uniform populations to compete, then renovation will be necessary.  A broadcast application of glyphosate in a spray-smother-spray program when establishing a new forage grass will also help reduce broomsedge populations. Managed rotational grazing will help shift the pasture back to desirable forages, if those forages are currently present, by reducing over grazing and increasing the potential of grazing of the broomsedge during more palatable stages of growth.  ∆

DR. ANTHONY OHMES: Agronomy Specialist, University of Missouri Extension