To Grass Species

Big Bluestem (Andropogon gerardii)

Plant Species
From Montana Interagency Plant Materials Handbook *
 By S. Smoliak, R.L. Ditterline, J.D. Scheetz, L.K. Holzworth, J.R. Sims, L.E. Wiesner, D.E. Baldridge, and G.L. Tibke

Bluestems are well represented throughout the world's warmer regions. Its stems are solid and pithy, differing in this respect from most other grasses, which are hollow. The vegetative cover offers good surface protection. Dead leaves form a good protective layer of litter on the soil surface.

Description

Big bluestem is a native, warm-season, perennial, tall grass with short, scaly, underground stems and roots that saturate the top 2 feet of soil and may reach depths up to 12 feet. Plants are often glaucous; culms robust, often in large tufts 3 to 6 feet tall. The lower sheaths and blades sometimes villous, flat, mostly 3/16 to 3/8 inch wide with scabrous margins. Inflorescence, a raceme on long-exerted peduncle usually purplish, sometimes yellowish. Seed stalks 3 to 8 feet tall appear from late August to October. The grass is sometimes called "turkey foot" bluestem because the seed head usually branches into three parts resembling a turkey foot. Big bluestem grows in large clumps and is extremely leafy. The lower leaves curl when dry and are easily pulled off at the base. Mature plants have a reddish cast after frost.

Adaptation

Big bluestem is found mostly in valley bottomland sites almost to the Rocky Mountains. However, it is found on dry soils, prairies and open woods, from Quebec and Maine to Saskatchewan and Montana, south to Florida, Wyoming, Utah, Arizona and Mexico. It grows on mostly fertile soils in the tall grass prairie, especially in the eastern half of Oklahoma and the Flint Hills of Kansas. It is most abundant on moist, well-drained loams of relatively high fertility.

Limitations

Combine run seed harvest usually contains excessive amounts of stems, chaff and other inert matter. The harvested seed usually requires additional cleaning before it can be seeded through a drill. It is best seeded through a grass drill that can handle chaffy seed.

Use for Hay

It makes good quality hay if mowed before stemmy seed heads have formed. Much of the native hay marketed in the Midwest consists of big bluestem and associated species.

Use for Pasture

Growth starts in late spring and continues throughout the summer. Few of the prairie grasses can equal big bluestem in quality or quantity of forage produced. It is palatable and relished by all classes of livestock and usually eaten in preference to the other grasses in the mixture. Through overuse and abuse this native grass has been killed out or greatly reduced on most of its original area since 1885. Big bluestem should never be grazed shorter than 6 to 8 inches during the growing season, leaving enough green leaves to promote fast regrowth. When continually grazed closer than 6 to 8 inches during the growing season, it decreases and is replaced by less productive plants.

Seed Production

Big bluestem seldom produces seed every year because the combination of plentiful moisture and moderate temperatures at the critical time of blooming rarely occurs. When it is grown in rows and cultivated, however, it consistently produces 150 to 200 pounds of seed per acre.

* The Montana Interagency Plant Materials Handbook (EB69) is no longer in print, but is available for viewing in
Montana County Extension Service and National Resource Conservation Service Offices.