Indian grass (Sorghastrum nutans) is a medium-sized grass that ranges from three to seven feet in height. It frequently grows in clumps, but it may also be found growing as a single stalk. The stem is hollow but stiff and upright.
The leaves are blue-green in color and flat. They may grow anywhere from 2 to 24 inches long and are no wider than half an inch. They feel rough and often waxy to the touch. Note that the tip is pointed and that the midrib is prominent near the leaf base. The leaves grow from open sheaths. Look closely at the point where the blade attaches to the stem—you should see a prominent pair of lobes resembling rabbit ears.
The inflorescence is a dense plume that may grow anywhere between 6 and 12 inches long. The plume starts out open and bronzy yellow, but later contracts and fades to gray. The tip of the plume is often nodding, while the branches that make up the inflorescence are hairy and gray. The branches bear paired spikelets that range in color from yellow to chestnut. As the plant flowers, note the prominent yellow anthers. Indian grass produces seeds with bent, twisted awns that are 1/2 to 3/4 inch long.
This species spreads by means of underground stems known as rhizomes, which it produces in abundance. These rhizomes are short and scaly.
Indian grass can be found across most of the United States, except for the west coast. It is the state grass of Oklahoma.
This species is highly adaptable and thus can be found nearly anywhere in Kansas, from prairies to open woods. It is most abundant where soils are deep, loamy, and moist, but that does not prevent it from growing on dry slopes and clay-based hardpan provided that it receives enough rainfall to become established. The pH of the soil is not a consideration. About the only thing that Indian grass can’t stand is total submersion.
This perennial warm-season grass starts the growing season by spreading via rhizomes, particularly in response to fire. Indian grass is quite tolerant of heat and drought and manages to grow remarkably quickly throughout the summer. Even if it does decrease throughout a pasture in response to drought stress, it should resume growth promptly when the rain falls again.
Indian grass flowers from July through mid-September, as it spreads by seeds, not just rhizomes. As fall progresses, the leaves turn golden yellow. Indian grass will usually have some color in its foliage throughout the winter.
Although Indian grass is quick to move into areas of disturbed soil, it is typically a dominant species of established native tallgrass prairies. It is particularly prevalent in moist, low-lying areas, where it may make up as much as 90% of the grass cover.
Indian grass is very important for prairie wildlife. The grass clumps provide cover for bobwhites, pheasants, prairie chickens, mourning doves, grassland songbirds, and a variety of small mammals, while the seeds offer vital nutrition to many of these species. The leaves provide food for skipper larvae and whitetail deer. The pollen is a food source for bees.
This plant is a very useful hay and pasture species for all types of livestock. It is at its best in the summer when tender and actively growing, while its palatability declines in fall and winter. Indian grass requires regular burning to stimulate its growth and to keep woody species in check. In pastures where both Indian grass and big bluestem are desired, a compromise is in order—annual burning will give Indian grass the advantage, while less frequent burning will allow big bluestem to become the more prevalent species. Overgrazing should also be avoided to keep Indian grass productive.
As a vigorous native, Indian grass is a good choice for erosion control on slopes. Cleaned and stratified (chilled, soaked, and treated) seed is a must to ensure successful planting and germination. The seed should be drilled at a rate of 10 pounds of pure live seed to the acre.
Indian grass is an attractive yet low-maintenance ornamental. It looks particularly well as a border, and it can also be added to cut flower arrangements for a rustic touch. The keys to maintaining Indian grass in the garden are to plant it in a sunny location and otherwise leave it alone. Too much fussing (e.g., applying fertilizer) will cause the stems to fall over.
Indian grass pollen is a mild seasonal allergen.
This species is rather distinctive, particularly when flowering. When in doubt, check the junction of the leaf blade with the stem to look for the unique rabbit ears.
Parts of a Grass Plant: A Glossary
Definitions for technical terms used in this post.