Western Wheatgrass (Smithii)

The Western Wheatgrass (Smithii) is generally described as a perennial graminoid. This is native to the U.S. (United States) has its most active growth period in the spring and summer and fall . The greatest bloom is usually observed in the mid summer, with fruit and seed production starting in the summer and continuing until fall. Leaves are not retained year to year. The Western Wheatgrass (Smithii) has a long life span relative to most other plant species and a rapid growth rate. At maturity, the typical Western Wheatgrass (Smithii) will reach up to 2 feet high, with a maximum height at 20 years of 0 inches.

The Western Wheatgrass (Smithii) 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 low vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -43°F. has high tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

Grazing/rangeland/hayland: Western wheatgrass is palatable to all classes of livestock and wildlife. It is a preferred feed for cattle, horses, deer, and elk in spring and is considered a desirable feed for sheep and antelope in spring. It is considered a desirable feed for cattle, horses, and elk in summer, fall and winter. In spring, the protein levels can be fairly high and decreases as it matures and cures out. This species is generally a relatively low forage producer, but can be utilized as native hay.

Erosion control/reclamation: Western wheatgrass is well adapted to stabilization of disturbed soils because of its strong spreading rhizomes. It does not compete well with aggressive introduced grasses during the establishment period, but is very compatible with slower developing natives such as bluebunch wheatgrass (Pseuoroegneria spicata), thickspike wheatgrass (Elymus lanceolatus ssp. lanceolatus), streambank wheatgrass (Elymus lanceolatus ssp. psammophilus), and needlegrass species (Nasella spp., Stipa spp., and Ptilagrostis spp.). Stands are generally slow to develop and may be non-existent the establishment year. However, over 50 percent stands are typically achieved by the end of the fourth growing season. Poor germination accounts for the poor initial establishment and strong rhizome spread accounts for stand development in later years. Its relative drought tolerance combined with strong rhizomatous root systems and adaptation to a variety of soils make this species ideal for reclamation in areas receiving 12 to 20 inches annual precipitation. Its low growth form, vigorous sod, and low maintenance requirements make it ideal for ground cover purposes. This grass can be used in urban areas where irrigation water is limited to provide ground cover and to stabilize ditchbanks, dikes, and roadsides.

General Characteristics

General: Grass Family (Poaceae). Western wheatgrass Pascopyrum smithii (Rydb.) A. Love (formerly) is perhaps one of the best known and most common of our native grasses. It is long-lived with an extensive, very strong, rhizomatous root systems combined with a few deep roots.

Stems arise singly or in small clusters and grow from 1 to 3 feet tall. The sheaths are hairy and the purplish auricles are clawlike and clasp the stem. The seed spike is stiff, erect and about 2 to 6 inches long. The awn-tipped (to 5mm) lemmas, paleas and glumes are generally glabrous or short-hairy. The ligule is inconspicuous and leaves are flat, very rough on the upper surface and margins, blue-green in color, with very prominent veins. Because of this bluish color, western wheatgrass is sometimes called bluestem or bluejoint wheatgrass.

Required Growing Conditions

It is a cool season perennial grass common to moist, sometimes saline to saline-sodic, medium to fine textured soils in the Great Plains, Southwest, and Intermountain regions of the western United States. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.

Cultivation and Care

Adaptation: Western wheatgrass is similar to thickspike and streambank wheatgrasses in appearance. However, it is coarser, its rhizomatous trait is more aggressive, and its coloration is blue-green rather than green. It is not as drought tolerant as thickspike or streambank wheatgrass. In comparison to thickspike and streambank wheatgrasses, it greens up and heads out later and total biomass production is generally higher. Thickspike and streambank wheatgrasses do better on medium to coarse textured soils. Streambank wheatgrass can be found on slightly heavy to medium to coarse textured soils. Western wheatgrass may be a better choice on heavy textured soils if rainfall is high enough. Western wheatgrass tolerates saline and saline-sodic soil conditions, poor drainage, and moderately severe drought. It will tolerate spring flooding, high watertables, and considerable silt deposition. It is very cold tolerant, moderately shade tolerant, and tolerant of fire if in the dormant stage. Recovery from fire however, is slow. It will not tolerate long periods of inundation.

On native sites western wheatgrass is most abundant in the 10 to 20 inch annual precipitation zones. Seeded varieties do best with 12 to 20 inches of precipitation. The natural geographic range of western wheatgrass is from southern Ontario and northern Minnesota, west to British Columbia, and south to west central California and western Texas from 1000 to 9000 feet elevation. Western wheatgrass is a component of many native plant communities and grows in association with blue grama (Bouteloua gracilis), buffalograss (Buchloe dactyloides), needlegrasses (Stipa spp.), bluebunch wheatgrass (Pseudoroegneria spicata), rough fescue (Festuca scabra), Idaho fescue (Festuca idahoensis), prairie junegrass (Koeleria cristata), and basin wildrye (Elymus cinereus).

Planting: Seed of western wheatgrass should be seeded with a drill at a depth of ¾ to ½ inch or less on medium to fine textured soils. Single species seeding rates recommended for western wheatgrass is 6 to 12 pounds Pure Live Seed (PLS) or 13 to 26 PLS per square foot. If used as a component of a mix, adjust to percent of mix desired. For mined lands and other harsh critical areas, the seeding rate should be increased to 18 to 23 pounds PLS or 40 to 50 PLS per square foot. Mulching and light irrigations are beneficial for stand establishment.

The best seeding results are obtained from seeding in very early spring on heavy to medium textured soils or in late fall on medium to light textured soils. Late summer (August - mid September) seedings are not recommended unless irrigation is available. It can also be established using sod. Seedling vigor is poor to fair; stands are generally slow to develop and may be non-existent the establishment year. However, over 50 percent stands are typically achieved by the end of the fourth growing season. Poor germination accounts for the poor initial establishment and strong rhizome spread accounts for stand development in later years.

It is moderately compatible with other species and can be used in seeding mixtures. It should not be seeded with strongly competitive introduced species. Under favorable conditions it can become a good weed barrier.

Stands may require weed control measures during establishment, but application of 2,4-D should not be made until plants have reached the four to six leaf stage. Mow when weeds are beginning to bloom to reduce seed development. Grasshoppers and other insects may also damage new stands and use of pesticides may be required.

Status

This is a native species.

General Upkeep and Control

Western wheatgrass “greens up” in March to early April and matures in mid-July to August. It makes good spring growth fair summer growth and good fall growth if moisture is available.

Western wheatgrass is palatable to all classes of livestock and wildlife. It is a preferred feed for cattle, horses, deer, and elk in spring and is considered a desirable feed for sheep and antelope in spring. It is considered a desirable feed for cattle, horses, and elk in summer, fall, and winter. In spring, the protein levels can be fairly high and decreases as it matures and cures out. This species is generally a relatively low forage producer, but can be utilized as native hay in areas where it is dense. Irrigation will improve western wheatgrass stands and aid in stand establishment. Weed control and fertilization help with stand establishment and overall production.

Established stands can withstand heavy grazing. Rotational grazing systems on western wheatgrass are recommended and 40 to 50 percent of the annual growth (3 to 4 inch stubble) should remain following grazing. Stands of western wheatgrass should not be grazed until they have firmly established. Six inches of new growth should be attained in spring before grazing is allowed in established stands.

Western wheatgrass is a low maintenance plant requiring little additional treatment or care. However, on better sites, stands can become sodbound and may need attention in the form of fertilization and moderate spring/fall deferment. Stands may also benefit from ripping if sodbound conditions occur to increase forage production. Care should be taken to avoid excessive tillage, because stands may be damaged.

Once established, western wheatgrass is very competitive with weedy species. Its primary pests include grasshoppers, ergot, and stem and leaf rusts.

Environmental Concerns: Western wheatgrass is long-lived, spreads primarily via vegetative means (rhizomes), but also may also spread via seed distribution. It is not considered weedy, but can spread into adjoining vegetative communities under ideal climatic and environmental conditions.

Seed Production Seed production of western wheatgrass has been very successful under cultivated conditions. Row spacing of 24 to 36 inches are recommended (although rhizomatous, it should be maintained in rows). Cultivation will be needed to maintain rows.

Seed fields are productive for three to five years. Average production of 75 to 150 pounds per acre can be expected under dryland conditions in 14 inch plus rainfall areas. Average production of 150 to 300 pounds per acre can be expected under irrigated conditions. Harvesting is best completed by direct combining or swathing in the hard dough stage, followed by combining of the cured windrows. Stands are prone to lodging and careful application of irrigation is recommended. Seed is generally harvested in late July to mid August.

Plant Basics
Category
Growth Rate Rapid
General Type Graminoid
Growth Period Spring, Summer, Fall
Growth Duration Perennial
Lifespan Long
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Mid Summer
Displays Fall Colors No
Shape/Growth Form Rhizomatous
Drought Tolerance High
Shade Tolerance Intolerant
Height When Mature 2
Vegetative Spread Moderate
Flower Color Yellow
Flower Conspicuousness No
Fruit/Seed Abundance Low
Fruit/Seed Seasonality Summer Fall
Seed Spread Rate Slow
Gardening Characteristics
Propagations (Ways to Grow) Seed
Moisture Requirements Medium
Cold Stratification Required No
Minimum Temperature -43
Soil Depth for Roots 20
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 4.5–9 pH
Precipitation Range 8–8 inches/yr
Planting Density 0–0 indiv./acre
Soil Textures Fine, Medium
Soil Depth for Roots 20
Minimum Frost-Free Days 90 day(s)
Salinity Tolerance High
CaCO3 Tolerance High
Sustainability & Use
Leaf Retention No
Palatability Medium
Fire Resistant No
Causes Livestock Bloating None

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