Grasses of the Eloise Butler Wildflower Garden

Big Bluestem is a perennial grass that likes dry open areas. It will reach full height only in full sun. It is a warm season grass, usually growing from short, scaly rhizomes and forming a dense tuft, above and below the soil level, and it forms sod. Rhizomes are not always present however.

Stems have a bluish to purplish-bronze color cast, often with a waxy bloom. The purplish-bronze color is more prominent in late season. It is very leafy at the base with some stem leaves.

Leaf blades vary from 2 to 20 inches long and up to 4/10ths inch wide. They frequently have a "v" shape with a prominent mid-vein, light green in color, with a reddish tinge near the tip.

The leaf sheath and collar area may be without hair but usually has fine whitish hair, particularly on the margins and at the base of the blade. The sheath is split and often has a purplish color at the base - this is most noticeable in late summer. The ligule is short with fine hair.

Inflorescence: The plant forms a conspicuous terminal seedhead in mid-August that breaks into 2 to 6+ branches, called 'rames' each up to 5 inches long; these bear repeating pairs of stalked and sessile spikelets. As the rames spread apart, particularly when they are three in number, they resemble turkey feet. The internodes of the rames are sparse to dense with whitish hairs.

Spikelets: On the rames are pairs of spikelets, one stalked which, when well developed which is the usual case, is staminate only, but sometimes it is absent or vestigial only and therefore sterile; the other spikelet is sessile, 3.5 to 12 mm long, and bisexual with three anthers, with glumes of about equal size. Awns form, 8 to 25 mm long with a twisted base and one bend. (Awns are bristle-like appendages at the tip of the seed that can make a twisting response to temperature and humidly changes and thus help the seed to work into the soil). Big Bluestem has about 10,000 seeds per ounce of weight. Disarticulation from the rame is below the sessile spikelet.

Habitat: Big Bluestem grows in prairies, meadows and areas with drier soil, but prefers slightly moist sites, and needs full sun, without which, it will lodge. It is top choice for erosion control when the site is moderately to well drained. It is a top forage plant and is used by birds for cover and nesting. It will not grow well where there is competition from weeds and cool season grasses. Cultivars are available from the nursery trade but this plant should be used for prairie restoration not necessarily the home landscape due to its height.

Names: The genus Andropogon applies to certain grasses that have hair on the spikelets resembling a man's beard. The word is derived from the Greek andros, meaning 'man' and pogon, meaning 'a beard. The species name, gerardii, is an honorary for French botanist and physician Louis Gerard (1733-1819) who developed a system of natural classification, published in 1761 as Flora Gallo-Provincialis. The author name for the plant classification, ‘Vitman’ refers to Fulgenzio Vitman (1728-1806), Italian botanist and clergyman. He developed the Brera Botanical Garden in Milan, which was restored in 1998.

Ornamental use: Several cultivars have been developed by the nursery trade that have a deeper bronze color to the stem and seed head. One is 'Blue Warrior' and another, even better, is 'Dancing Wind' (photo below). Note our article on Growing Landscape Grasses in Minnesota.