Smooth Brome

Smooth Brome, courtesy of Intermoutain Herbarium

© Intermountain Herbarium,

Common Name(s):

Smooth Brome

Scientific Name:

Bromus inermis Leyss.

Scientific Name Synonyms:

None known




Life Span: Perennial

Origin:Introduced (from Europe)

Season: Cool

Growth Characteristics: An erect, leafy, long-lived perennial, 1 ½ to 3 feet tall, rhizomatous and commonly producing a dense sod. It starts growth in early spring; flowers May to July; reproduces from seeds, tillers, and rhizomes. It may regrow and reflower in the fall if moisture is sufficient.

Seedhead:Compact to somewhat open panicle, 4 to 8 inches long; panicle branches in whorls; spikelets ¾ to 1 inch long, slender, turn brownish at maturity, contain 5 to 10 florets; lemmas awnless to awn-tipped, glabrous and split near the tip, into a bifid apex.

Leaves: Glabrous or occasionally pubescent, particularly on the sheaths; blades 8 to 15 inches long, ¼ to ½ inch wide, flat, with a raised and keeled midrib below; sheaths closed, except near collar, and papery when dry; leaves rolled in the bud; ligules up to 1/8 inch long, rounded, and membranous; auricles absent.

Ecological Adaptations:

Smooth brome was introduced from Europe and has been used in range seedings in many areas of the country. Smooth brome is a good forage producer on the mountain loam sites, and it is also adapted to the upland sites. In the lower rainfall areas, some irrigation is required for optimum production. The elevation range for this grass varies from 3,000 to 12,000 feet. Smooth brome comes on fairly early in the spring, but is not as early as intermediate wheatgrass with which it compares very closely in its adaptations.

Due to it's aggressiveness, the species can be considered weedy. It is not tolerant of prolonged flooding.

Soils: It is best adapted to fertile, loamy, deep soils including stony loams where there is at least 16 inches of rainfall annually, or supplemental irrigation equivalent to that. Smooth brome is mildly alkaline and moderately salt tolerant.

Associated Species: Slender wheatgrass, intermediate wheatgrass, aspen, yarrow, big sagebrush.

Uses and Management:

Smooth brome is excellent forage for all classes of domestic livestock and for wildlife. Its quality and palatability rapidly decline after inflorescence development. Regrowth in the fall can furnish valuable fall grazing. Smooth brome can withstand heavy use, but produces best with 60% use. If it is grazed too closely for too long it becomes "sodbound" and unproductive.

Smooth brome is excellent for the control of soil erosion and is used widely for rehabilitation of rangeland for purposes including forage production, wildlife habitat, landscape beautification, cover for recreational areas and campgrounds, roadside seedings, and for watershed stabilization.

Fertilization with nitrogen fertilizer or interseeding with nitrogen fixing legumes is recommended, especially for older smooth brome stands. Recently, it has been determined to be very competitive with desirable native species, so it is often not recommended for restoration seed when other seed is available.