Pascopyrum smithii (Rydb.) Á. Löve
Poaceae (Grass Family)
Synonym(s): Agropyron molle, Agropyron smithii, Agropyron smithii var. molle, Agropyron smithii var. palmeri, Elymus smithii, Elytrigia smithii, Elytrigia smithii var. mollis
USDA Symbol: pasm
Western Wheatgrass is a 10-36 in., cool-season, sod-forming, perennial grass. Its dense, narrow, 3-6 in. spikes occur at the top of stout culms. The entire plant is often covered with a white coating, lending a silvery caste to its blue-green leaves. The leaves are less than a quarter inch wide and, when dry, roll up longitudinally to display prominent ridges on the tops.
This densely colonizing turf grass is commonly found in western North America in low-lying areas subject to seasonal poor drainage. During wet times, this grass becomes aggressive and can crowd out neighboring grasses and forbs. For this reason, and for its silvery blue-green leaves, Western Wheatgrass is favored for erosion control. It covers so thickly, however, that it is not the best choice for a wildflower meadow. It won't allow many other plants room.
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Root Type: Fibrous
Leaf Arrangement: Alternate
Leaf Complexity: Simple
Leaf Venation: Parallel
Fruit Type: Caryopsis
Size Notes: Up to about 3 feet tall.
Leaf: Gray-green, blue-green, or silvery green
Bloom InformationBloom Color: Yellow
Bloom Time: May , Jun
DistributionUSA: AK , AR , AZ , CA , CO , GA , IA , ID , IL , IN , KS , KY , MA , MI , MN , MO , MT , ND , NE , NH , NM , NV , NY , OH , OK , OR , SD , TN , TX , UT , WA , WI , WY
Canada: AB , SK
Native Distribution: Ont. to B.C., s. to KY, TX, AZ & e. of the Cascades to n.e. CA
Native Habitat: Hillsides; bottomlands; canyons; open woods; prairies; scrubland. Often in swales and ditches with seasonal poor drainage.
Growing ConditionsWater Use: Medium
Light Requirement: Sun , Part Shade
Soil Moisture: Moist
CaCO3 Tolerance: High
Drought Tolerance: High
Soil Description: Moist, alkaline clay, loam, sand.
Conditions Comments: Thrives in seasonal poor drainage and high-rainfall years, when it can become aggressive enough to crowd out many other grasses and forbs.
BenefitUse Ornamental: A blue-green turf grass that can be mowed
Use Other: Widely used for erosion control
PropagationPropagation Material: Root Division , Seeds
Description: Increase is easiest by rhizome division. Seeds have poor germination.
Seed Treatment: A KNO3 enrichment enhances germination but is not necessary.
Commercially Avail: yes
Maintenance: If gets too aggressive, reduce water.
Find Seed or Plants
Order seed of this species from Native American Seed and help support the Wildflower Center.
Find seed sources for this species at the Native Seed Network.
View propagation protocol from Native Plants Network.
Mr. Smarty Plants says
Plants to stop erosion in Arizona
January 17, 2009
I'm looking for a plant to stop erosion; I have big wash outs that are starting to erode my yard so I guess I'm looking for deep rooting plants. I live south of Tucson, Arizona. If you can advise me...
view the full question and answer
National Wetland Indicator Status
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Texas Parks and Wildlife Department - Austin, TX
Native Seed Network - Corvallis, OR
BibliographyBibref 946 - Gardening with Prairie Plants: How to Create Beautiful Native Landscapes (2002) Wasowski, Sally
Bibref 841 - Native Alternatives to Invasive Plants (2006) Burrell, C. C.
Bibref 318 - Native Texas Plants: Landscaping Region by Region (2002) Wasowski, S. & A. Wasowski
Search More Titles in Bibliography
Web ReferenceWebref 38 - Flora of North America (2019) Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
From the ArchiveWildflower Newsletter 1989 VOL. 6, NO.4 - Spring Climbs Rockies Slowly, Colorado Cooler, Conference of Wildflower and Nati...
Additional resourcesUSDA: Find Pascopyrum smithii in USDA Plants
FNA: Find Pascopyrum smithii in the Flora of North America (if available)
Google: Search Google for Pascopyrum smithii
MetadataRecord Modified: 2023-01-25
Research By: TWC Staff