Broomsedge Bluestem: What is it?

Have you noticed a two foot tall, orange or copper colored plant in your pasture this winter or while driving down the road? It's broomsedge bluestem.

Historically, housewives used the long, bush-like grasses to make a broom, which accounts for the common name. Broomsedge is a warm season native perennial grass, not a sedge like the name implies, and is often confused with little bluestem. It is a bunch grass that grows as a hardy clump. It dies back every fall and then regrows from the same root mass the following spring. Broomsedge is a relatively short-lived perennial with existing plants only surviving about three years.

Cattle will avoid grazing this plant except in the early spring when it is small. As the plant, matures, it becomes extremely unpalatable. So with it being undesirable to cattle, it is obviously a plant that we do not want in pastures.

Broomsedge might be considered as an opportunistic plant -- it takes advantage of opportunities but does not force itself into pastures. It will become established most easily in situations where pastures are undergrazed in the spring and early summer but overgrazed mid to late summer. Undergrazing in the spring allows the young broomsedge plants to grow and then reach the stage of growth where it becomes unpalatable.

Broomsedge tends to show up in areas where a nutrient deficiency exists. Low levels of phosphorus is typically the problem. There is also some evidence that low pH levels may be to blame as well, or even a combination of both low phosphorus and low pH.

Controlling broomsedge in fescue pastures will require some patience. Since it is a short lived perennial, anything to make desirable grasses more competitive and reduce the survival of any new broomsedge seedlings should be done. This includes grazing heavier in the spring and early summer while the broomsedge is small and more palatable. In addition, a good fertility program must be implemented.

A soil test should be done. Once the fertilizer rate is determined, you will need to continue the recommended applications for a few years before you see a reduction in broomsedge stands. Even then, you will still not want to reduce the fertilizer unless another soil tests indicates so. A majority of the soil tests that come into the extension office are low in phosphorus. Soil tests can be submitted through the extension office and are $10 each.

In cases where there is a thick stand of broomsedge and only a low population of desirable forage plants, it may be advantageous to renovate the pasture. This would require killing the existing broomsedge with either non-selective herbicide or with tillage, reseeding and continuing with a good fertility program.

Broomsedge control in native grass is a little trickier.

Cultural practices such as burning and grazing management should be used to hopefully reduce or at least slow the spread. Native grasses do not respond to fertilizer the same as introduced grasses, so fertilizing is not the answer.

Editor's Note: Delta George is a K-State Research and Extension agriculture and 4-H extension agent assigned to Bourbon County. She may be reached at (620) 223-3720.