The Big Four

Becky Emerson Carlberg

The orange harvest moon brightened the Monday night sky. The Fall equinox arrives today. Summer is history. Penny, second grader in Mrs. Taylor’s class in Michigan, put it so well:

Hello fall,

Goodbye summer.

Hello School,

Goodbye hot weather.

Hello leaves falling,

Goodbye pool.

Hello jackets,

Goodbye shorts.

Autumn is my favorite time of year. The native prairie grasses are coming into season, and it has taken them months to attain their true heights and fullness. Oklahoma has three types of prairies: short grass, mixed grass and tall grass. Appreciate these grasslands since less than ten percent of the original prairies from even five hundred years ago remain because of agriculture, restructure and development. The tall grass prairies used to cover much of central North America.

The Big Four are four distinct tall grasses in Oklahoma: Switchgrass, Big bluestem, Little bluestem and Indian grass.

Switchgrass (Panicum virgatum) has generated much interest in energy production. This is a thick bunch grass reaching over nine feet in height. Blue-green leaves with short thick white fuzz at their bases are a diagnostic trait. This grass energetically produces underground stems, or rhizomes, as well as roots. From the rhizomes may sprout separate switchgrass plants, similar in growth to strawberries. Long fibrous roots penetrate the soil six feet down. Tough, like subtle little jack hammers, the roots even drill through hardpan.

As the season progresses, stiff branches of switchgrass spring up from the center, each supporting small grass spikelets. The spikelet is composed of one or more flowers. Grass flowers are small, very streamlined and designed for wind pollination.

Deep soils of shale or limestone support the Bluestem grasses. The tallest of the bluestems is Big Bluestem (Andropogon gerardii), fondly known as Turkeyfoot since the spikelets distributed along each stem look like turkey feet walking up to the sky. The young bluish shoots of Big Bluestem are loved by bison and cattle. The warm season grass blooms in August and September. It stands out in tallgrass prairies, often reaching over eight feet in height. Dense roots travel ten feet deep. So thick are these prairie anchors that not only Big Bluestem, but Little Bluestem and Indian Grasses were harvested to make the bricks used in sod houses.

Only one sod house built by settlers in Oklahoma survives. Marshal McCully participated in the Cherokee Run in 1893, staked his claim and built his soddy a year later. His home is located near Cleo Springs in Alfalfa County.

Little Bluestem (Schizachyrium scoparium) is the opposite of Big Bluestem. Single spikelets are born on round grass stems (known as culms) originating from ground level. The stems form thick clusters two to five feet tall. Roots go five to eight feet deep. Little Bluestem is very prominent in tallgrass prairies. The leaves are indeed bluish in color. The flowers are feathery along the stems and turn a reddish color as the seeds mature. Another warm season grass, Little Blue provides cover and food for wildlife and is nearly cosmopolitan. It can be found in all but four US states.

The amazing Indian grass (Sorghastrum nutans) is another formidable Big Four grass in the prairies of Cross Timbers. The warm season tall grass grows in clumps or individual stems with blue-green leaves. The stunning floral heads form September until late October. One can easily spot the golden arrows waving in the breeze. The panicle (the arrangement of spikelets) has matured and the pollen is just beginning to blow in the Oklahoma wind. Indiangrass is found in every county of Oklahoma as well as much of the entire United States. It not only makes good hay, but cover for small mammals.

If you are wondering why the Big Four grasses have ‘warm season’ in common, realize they grow best in warm soil and higher temperatures: spring, summer and fall in Oklahoma. Go out and become familiar with the native grasses. They are far more valuable than Bermuda!

Monarchs are on the move. Godspeed to every butterfly!