Broomsedge Bluestem

Broomsedge Bluestem

Yesterday, I was asked to identify a grass that was invading a grass hayfield near West Lafayette. The 12-inch tall specimen was in a plastic sandwich bag. The old growth of 2020 was beige-bronze in color, narrow leaved, and had tufts of pubescence remaining. Most seed had been windblown during the fall and winter. My “hunch” as I approached the sample on the table was broomsedge bluestem (Andropogan virginicus). The warm-season perennial bunchgrass was just breaking winter dormancy and had very flat and narrow leaf sheaths. I reached for my cell phone and used a plant identification app. Whoever programmed the app thought the plant was broomsedge bluestem, too!One of my first Purdue Extension in-field education events in the early 1980’s was my introduction to broomsedge bluestem. Areas of the southern Indiana grass pasture had more broomsedge bluestem than the desired forages that were seeded. I recall that a farmer leaned over and said “We call it poverty weed”. I once thought that broomsedge bluestem was a southern Indiana plant only, but as the years have gone by I see the plant all over Indiana. A few years ago, a group of farmers were doing sensory analyses of different hay samples and chemical analyses were available, too. One of the samples on display, was broomsedge bluestem. The chemical forage analysis verified why the grass has the nickname poverty weed. It would have made better bedding than a feed resource.Andropogon virginicus is a species of grass known by several common names, including broomsedge bluestem, yellowsedge bluestem and (in Australia, because it was introduced to that country after being used as packaging for bottles of American whiskey) whiskey grass. It is native to the southeastern United States and as far north as the Great Lakes. It is known as an introduced species in California and Hawaii, where it is weedy.

Broomsedge is a native grass that grows well on sites that have low fertility or pH. It is allopathic, meaning it produces a toxin that inhibits the growth of other plants. Most animals will avoid grazing this plant except in the early spring and when another forage is not available. This explains why Broomsedge can become the dominant species in a pasture. Broomsedge is an opportunistic plant that takes advantage of poor fertility management and overgrazing. It also is a good indicator of needed management changes to the grazing system. A common question at most Extension offices is how to get rid of broomsedge bluestem.Broomsedge bluestem, Andropogon virginicus L., is a native warm season perennial bunch grass that prefers to grow in areas with sandy, moist soils that have low fertility. It is considered to be an indicator plant, and is commonly found in soils with low phosphorus availability. It has a small/shallow root system, grows 2-4 feet tall, and is a quickly growing plant. Seeds germinate in the spring after soil temperatures begin to exceed 55°F. Plants require 2-3 years of growth before producing seed. Broomsedge Bluestem is a native warm-season, bunchgrass that grows best on light to sandy soils in the Eastern half of the U.S. This grass gets its name historically from gathering mature bunches, tying them together and using them for a broom. Palatability of this grass is poor unless grazed or hayed very early. It does thrive however, on low quality soils or those low in fertility providing erosion control and valuable wildlife cover or nesting. In fall, Broomsedge turns a brilliant reddish-orange color and holds that color through the winter. (Source: www.stockseed.com)