774 Andropogon gerardiiCommon Names: big bluestem, turkey foot bluestem Family: Poaceae (grass Family)
Big bluestem is a perennial bunch grass that forms large clumps which expand slowly on short, scaly rhizomes. It normally grows to 5-7 ft (1.5-2.1 m) in height, but under ideal conditions can get more than 10 ft (3.0 m) tall. The habit is fairly upright, and not as arching as some ornamental grasses. Look for the blue color at the base of the stems. The stems and leaves are blue-green in early summer, developing reddish tinges as they mature. The plants turn a rich copper or orange-brown in autumn and develop an overall reddish or burgundy cast after frost. In late summer, big bluestem produces terminal 3 in (7.6 cm) bronze to purplish seed heads that stand above the foliage. The flowering stalk has three finger-like branches that look to some like a turkey's foot; interesting, but not very showy. The foliage stays attractive through winter, but the seed heads disintegrate. 'Roundtree' is a little smaller than the species and a little earlier blooming. 'The Blues' has more of a blue-gray foliage. 'Pawnee' is more drooping in habit.
Big bluestem occurs naturally from southern Quebec and Ontario, west to Manitoba and Saskatchewan, and south to Arizona, New Mexico, Texas, northern Mexico and northern Florida. It grows in prairies and open woods. Big bluestem was the most abundant and tallest grass in the vast Great Plains prairies that once covered much of central North America.
CultureBig bluestem is adaptable to a wide range of soils; it thrives in light, porous soils as well as heavier, less well drained soils, even clays. It tolerates acidic or alkaline soils. It does well in dry or humid climates and tolerates cool as well as hot summers. A healthy clump of big bluestem gradually expands outward and the center tends to die back, so divide every few years, discarding the center and replacing with younger, more vigorous clumps that grow on the outer edges. Cut to the ground in early spring before new growth begins. Light: Full sun. Big bluestem will become lanky and flop over if grown in the shade. Moisture: Big bluestem develops a tremendous root system which saturates the top 2 ft (0.6 m) of soil and reaches depths of 12 ft (30.5 m). Once established, it is very drought-tolerant. However, best growth occurs with regular watering, and plants that get adequate moisture throughout the growing season can get more than 10 ft (25.4 m) tall. Big bluestem can withstand short periods of waterlogged soils in summer, but not in winter. Hardiness: USDA Zones 3 - xxx. 9 Propagation: Propagate bluestems by seed or by dividing the root mass.
Big bluestem is grown for its lush summer foliage and reliable fall and winter color. This is an adaptable, carefree grass that is well suited for naturalizing in a meadow or prairie garden. In a large landscape, plant big bluestem in sweeping drifts behind flowering plants like goldenrods (Solidago spp.), coneflowers (Echinacea purpurea), sunflowers (Helianthus annuus), daisies (Leucanthemum X superbum), and zinnias (Zinnia elegans). The flowering stems can get over 8 ft (20.3 m) tall, but they aren't dense with foliage and you can see right through them, so you don't have to relegate big bluestem to the rear. Take advantage of the see-through quality and grow big bluestem with tall, bright colored flowers like purpletop verbena (Verbena bonariensis), Mexican sunflower (Tithonia rotundifolia) and blazing star (Liatris). A row of big bluestems makes a suitable border or screen and a single plant is an attractive specimen in a mixed border.
Big bluestem, the "King of Grasses", is the official Illinois prairie grass. It produces better quality and greater amounts of forage than any other native American prairie grass. Cows and bison love it. Big bluestem once dominated the tall-grass prairies of North America, forming rippling waves of amber taller than a man on horseback from the Rocky Mountains to the eastern forests. But most of the prairie was plowed under so European settlers could grow corn and wheat. Remnants of the original prairie still persist in old cemeteries, along railroad tracks, between airport runways, and in a few scattered ranches, mostly owned by The Nature Conservancy or Ted Turner. Although the prairies are largely gone, big bluestem is still an important forage grass in parts of the Mississippi valley and a dominant component in prairie hay.
There are more than 6000 species of grasses in the world and some 100 species of Andropogon. Most bluestems are important forage grasses, and only a few are important as ornamentals. Splitbeard bluestem (A. ternarius) and little bluestem (A. scoparium) are two very attractive American natives that deserve more attention from gardeners.
Steve Christman 8/5/00; updated 9/26/03