Cheatgrass (Tectorum)

The Cheatgrass (Tectorum) is generally described as an annual graminoid. This is not native to the U.S. (United States) .

Uses of : Landscaping, Medicinal, Culinary, etc.

Noxiousness: Downy brome or cheatgrass is native to the Mediterranean region. In Europe, its habitat was the decaying straw of thatched roofs. ‘Tectum’ is Latin for roof, hence the name Bromus tectorum, ‘brome of the roofs’. Introduced into the United States in packing materials and perhaps as a contaminant of crop seeds, downy brome was first found in the United States near Denver, Colorado, in the late 1800s (Whitson et al. 1991). In the late 1800’s and early 1900’s, it spread explosively in the ready-made seed-beds prepared by the trampling hooves of overstocked range livestock. Disturbance associated with homesteading and cultivation of winter wheat accelerated its spread and establishment. By the 1930’s, cheatgrass had become the dominant grass over whole counties in the Pacific Northwest and the Intermountain area, and the “worst” western weedy range grass.

Downy brome has developed into a severe weed in several agricultural systems throughout North America, particularly pastureland, western rangeland, and winter wheat fields. It is now estimated to infest over 41 million hectares (101 million acres) in the western states (Mack 1981). Winter wheat growers in the western United States proclaim it as their worst weed problem. In the Palouse wheat country in the Pacific Northwest, at high density, it will reduce wheat yields by an average of 27% (FICMNEW, 1997). It can reduce seed yield of winter rye as much as 33%, detrimental effects being greatest when it emerges within six weeks of the grain crop. In winter wheat and alfalfa fields, it is especially troublesome, because of its ability to reproduce prior to crop harvesting (Peepers 1984). It is an aggressive invader of sagebrush, pinyon-juniper, and other shrub communities, where it can completely out-compete native grasses and shrubs. Approximately five million hectares of overgrazed rangeland in Idaho and Utah are covered by almost pure stands of cheatgrass (FICMNEW 1997). Recent serious problems with downy brome have been reported in the New England nursery trade and in orchards (Morrow & Stahlman 1984).

Dense stands of cheatgrass on rangeland are highly flammable in late spring and summer after maturation, which usually occurs before native species enter summer and autumn dormancy. Consequently, its presence, in altering the timing and occurrence of range fires, negatively impacts other species. Although it provides forage early in the season, the plants soon mature and turn brown, leaving few competing species for late season forage. Moreover, in drought situations the presence of Bromus tectorum causes rapid depletion of soil moisture, thus serving to retard or prevent the establishment of perennial grasses (Welsh 1981).

Mature plants are unpalatable, the characteristic drooping seed heads becoming brittle as the plant dries, shattering upon disturbance and disseminating the sharp-tipped lemmas with their barbed awns. These can work their way into eyes, nostrils, mouths, and intestines of grazers. Put succinctly by Aldo Leopold (1949), he writes “to appreciate the predicament of a cow trying to eat mature cheat, try walking through it in low shoes. All field workers in cheat country wear high boots.” Leopold was perhaps one of the first authors to bring to the general public an awareness of the impact of downy brome in the west. In his essay “Cheat Takes Over,” he addresses the ecological implications of its establishment with clarity and humor. His list of negative impacts and noxious characteristics are: replacement of rich and useful native bunchgrasses and wheat-grasses with the inferior cheat; prickly awns that, when mature, cause cheat-sores in the mouths of cows and sheep; extreme flammability of cheat-covered lands that results in burn-back of winter forage such as sagebrush, bitterbrush, and native perennial grasses, and destruction of winter cover for wildlife; degradation of hay following invasion of alfalfa fields; and block

General Characteristics

General: Grass Family (Poaceae). Downy brome is a small annual or winter annual, softly short-hairy throughout, generally 1-6 dm tall. Stems are solitary or in a few-stemmed tuft. Ligules are short (usually 1-2 mm long), membranous, and fringed at the top; auricles are lacking. Leaf blades are up to 2 dm long, flat, relatively narrow (usually 2-5 mm wide), and generally long-ciliate near the base. The roots are fibrous; the plants do not root at the nodes. The inflorescence is a soft and drooping, much-branched, open panicle, usually becoming a dull red-purple color as it matures. Spikelets are about 1.5-2.0 cm long with 3-6 florets. The glumes are shorter than the florets, the first 1-veined and the second 3-veined. Lemmas are glabrous to densely hairy, more-or-less rounded on the back, and with nearly straight awns that are 7-18 mm long. Flowering is from May to July. Reproduction is by seed. Germination occurs in fall to spring, depending on the climate and rainfall (Hickman 1993; Gleason & Cronquist 1991; Cronquist et al. 1977; Muenscher 1955; Uva et al. 1997).

General Upkeep and Control

CAAM2"This plant can produce abundant volunteers from the many seeds that drop to the soil. The flowers are produced on new growth, so prune plants after the fruits are gone to increase the next year’s growth and berry production. The plants can take a hard pruning and may be pruned to the ground level in the winter if desired. ",

Plant Basics
General Type Graminoid
Growth Duration Annual
Plant Nativity Introduced to U.S.

Source: USDA, NRCS, PLANTS Database,
National Plant Data Center, Baton Rouge, LA 70874-4490 USA