Smooth Brome (Inermis)

The Smooth Brome (Inermis) is generally described as a perennial graminoid. This is not native to the U.S. (United States) and has its most active growth period in the spring and fall . The greatest bloom is usually observed in the late spring, with fruit and seed production starting in the summer and continuing until summer. Leaves are not retained year to year. The Smooth Brome (Inermis) has a long life span relative to most other plant species and a moderate growth rate. At maturity, the typical Smooth Brome (Inermis) will reach up to 2.5 feet high, with a maximum height at 20 years of 0 inches.

The Smooth Brome (Inermis) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by seed. It has a slow ability to spread through seed production and the seedlings have high vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -38°F. has medium tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Livestock: Smooth brome may be used for hay, pasture, or silage. It is compatible with alfalfa or other adapted legumes. The grass is highly palatable and is high in protein content and relatively low in crude-fiber content.

Erosion Control: Since the plant has a massive root system and is a sod former it can be used effectively for critical area planting and grassed waterways if the areas can be irrigated or where annual precipitation exceeds 20 inches.

Wildlife: Smooth brome can be used as a component in various upland wildlife and conservation cover mixes for nesting cover and food. Note: This species is no longer recommended for wildlife use in some states because of its aggressive nature.

General Characteristics

Bromus inermis, smooth brome, is a leafy, sod-forming, perennial, cool season grass that spreads by rhizomes. This species is both native and introduced. The stems vary in height from 2 to 4 feet. The plant produces numerous basal and stem leaves that vary in length from 4 to 10 inches. Frequently the leaves are marked by a transverse wrinkle resembling a “W” a short distance below the tip. The flower head develops a characteristic rich purplish-brown color when mature. The seed is produced in semi-compact 5 inch long panicles with ascending branches. The flat compressed seed is usually awnless, about 1/3 inch long, and smooth. There are approximately 136,000 seeds per pound. Smooth brome is the most widely used of the cultivated bromegrasses and has been cultivated in the U.S. since the early 1880s.

BUDA.FS (buffalograss)","Buchloe dactyloides (Nutt.) Engelm., buffalograss, is a perennial, native, low-growing, warm-season grass. Leaf blades are 10 to12 inches long, but they fall over and give the turf a short appearance. Staminate plants have 2 to 3 flag-like, one-sided spikes on a seedstalk 4 to 6 inches long. Spikelets, usually 10, are 1/8 inch long in two rows on one side of the rachis. Pistillate spikelets are in a short spike or head and included in the inflated sheaths of the upper leaves. Both male and female plants have stolons from several inches to several feet in length, internodes 2 to 3 inches long, and nodes with tufts on short leaves.

Required Growing Conditions

Smooth brome is best adapted to cooler climates and is generally hardier than tall fescue or orchardgrass. It is resistant to drought and extremes in temperature. This plant is very susceptible to disease in areas of high humidity. Smooth brome grows best on slightly acid to slightly alkaline well drained clay loam soils with high fertility but it will also grow well on lighter textured soils where adequate moisture and fertility are maintained. Smooth brome performs best in a pH range of 6.0 to 7.5. Stands are difficult to obtain and growth is poor on soils high in soluble salts.

Smooth brome is distributed throughout most of the United States.

Cultivation and Care

A clean firm seedbed is needed. Due to the slow germination and establishment of smooth brome, spring seedings are especially preferred in the northern states. In southern areas, late summer seedings are a second option. Fall seedings should be made at least 6 weeks before a killing frost is expected. Seeding rates are typically 5-10 pounds per acre in mixtures, and about 15 pounds when seeded alone. When smooth brome is seeded in a mixture with alfalfa, the alternate row method will give the best results. For seed production plantings under irrigation, seed in rows 30 to 42 inches apart at a rate of 3 to 4 pounds per acre. Seedings should be drilled at a depth of 1/2 to 3/4 inch. If broadcast increase the seeding rate and cultipack after planting.


This plant has threatened status in Michigan.

General Upkeep and Control

Smooth brome requires heavy early spring and fall applications of nitrogen to maintain high yields in a pure stand. Mixtures with alfalfa will require less nitrogen but the alfalfa will usually need P205 each year to maintain vigor. Alfalfa cannot be maintained in pasture seedings without rotation. Best forage production is obtained from smooth brome when used in a planned cropping system and plowed out after 3 to 4 years. Its heavy sod makes it an excellent soil conditioning crop when included in cropping systems. In deep, well-drained soils it will root to 4 feet.

Smooth brome performs best in grassed waterways, field borders, and other conservation uses where the forage can be cut and removed while in early bloom. Do not graze the new seeding; cut the first crop for hay.

In bromegrass-legume pastures, allow the legume to go to bud or early-bloom stage before turning cattle in to avoid bloat hazard, and manage thereafter for optimum regrowth of the legume. Pastures should not be grazed prior to smooth brome attaining a minimum height of about 10 inches at the beginning of the grazing season. Grazing pressures should be adjusted throughout the season to avoid grazing this grass to less than a minimum height of 4 inches. Grazing schedules should be so arranged that a regrowth period of 28 to 35 days between grazing periods is available.

Pests and Potential Problems Grasshoppers and seedling blight are influences that may impede establishment. Foliar diseases are more common in humid areas and seasons. The bromegrass seed midge, Stenodiplosis bromicola, can seriously hinder seed production.

Cultivars, Improved, and Selected Materials (and area of origin) Northern type cultivars: ‘Superior’, ‘Manchar’, ‘Carlton’, ‘Jubilee’, ‘Saratoga’ (various), ‘Polar’, ‘Bravo’

Southern type cultivars: ‘Lincoln’ (Hungary), ‘Achenbach’, ‘Elsberry’, ‘Lancaster’, ‘Lyon’, ‘Southland’, ‘Rebound’, ‘Baylor’ (various), ‘Beacon’

Plant Basics
Growth Rate Moderate
General Type Graminoid
Growth Period Spring, Fall
Growth Duration Perennial
Lifespan Long
Plant Nativity Native and Introduced to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Late Spring
Displays Fall Colors No
Shape/Growth Form Rhizomatous
Drought Tolerance Medium
Shade Tolerance Intolerant
Height When Mature 2.5
Vegetative Spread Rapid
Flower Color Yellow
Flower Conspicuousness No
Fruit/Seed Abundance High
Fruit/Seed Seasonality Summer Summer
Seed Spread Rate Slow
Gardening Characteristics
Propagations (Ways to Grow) Seed
Moisture Requirements Medium
Cold Stratification Required No
Minimum Temperature -38
Soil Depth for Roots 12
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Regrowth Rate Moderate
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 5.5–8 pH
Precipitation Range 18–18 inches/yr
Planting Density 0–0 indiv./acre
Soil Textures Fine, Medium
Soil Depth for Roots 12
Minimum Frost-Free Days 90 day(s)
Salinity Tolerance Low
CaCO3 Tolerance Low
Sustainability & Use
Leaf Retention No
Palatability Medium
Fire Resistant No
Causes Livestock Bloating None

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