Grass or grass-like · Poaceae
Western wheatgrass
Pascopyrum smithii
Western wheatgrass is recorded as native to 29 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 703 counties of those states by USDA PLANTS.
Key facts · USDA PLANTS
Western wheatgrass at a glance
- Native in
- 703 counties, across 29 states and territories
- Estimated cold hardiness
- Zone 3a PLANTS minimum temperature −43°F
- Mature height
- 2 ft PLANTS mature height
- Light and water
- Full sun (shade-intolerant) Medium water use
Estimated cold hardiness: zone 3a. PLANTS gives a minimum temperature of −43°F; zone 3a winters bottom out at −40°F, the coldest half-zone that stays within that limit.
Western wheatgrass is recorded as native to 29 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 703 counties of those states by USDA PLANTS.
Counties where it is native
The 15 counties with the most ZIP codes among the 703 where it is listed.
Native counties by state
- Arizona 7 counties
- California 7 counties
- Colorado 47 counties
- Georgia 1 county
- Idaho 17 counties
- Illinois 43 counties
- Indiana 25 counties
- Iowa 37 counties
- Kansas 96 counties
- Kentucky 4 counties
- Massachusetts 1 county
- Michigan 13 counties
- Minnesota 29 counties
- Missouri 25 counties
- Montana 15 counties
- Nebraska 54 counties
- Nevada 9 counties
- New Hampshire 1 county
- New Mexico 25 counties
- New York 2 counties
- North Dakota 43 counties
- Oklahoma 21 counties
- Oregon 12 counties
- South Dakota 24 counties
- Texas 53 counties
- Utah 24 counties
- Washington 11 counties
- Wisconsin 34 counties
- Wyoming 23 counties
Growing traits
Values from the PLANTS characteristics record. “Not recorded” means PLANTS has no value; nothing here is estimated except the zone.
Growth
- Growth habit
- Graminoid
- Duration
- Perennial
- Mature height
- 2 ft
- Growth rate
- Rapid
- Growth form
- Rhizomatous
- Shape
- Semi-Erect
- Lifespan
- Long
- Active growth period
- Spring, Summer, Fall
Light and water
- Shade tolerance
- Intolerant (full sun (shade-intolerant))
- Moisture use
- Medium water use
- Drought tolerance
- High
- Tolerance of waterlogged soil
- Medium
- Precipitation range
- 8 to 36 in per year
Soil
- Soil textures
- Medium and fine
- pH range
- 4.5 to 9
- Lime (CaCO₃) tolerance
- High
- Salinity tolerance
- High
- Fertility requirement
- Medium
- Minimum root depth
- 20 in
Climate
- Minimum temperature
- −43°F
- Estimated cold hardiness
- Zone 3a and warmer
- Minimum frost-free days
- 90
- Fire tolerance
- High
Flowers, leaves and fruit
- Flower color
- Yellow
- Showy flowers
- No
- Bloom period
- Mid Summer
- Foliage color
- Gray-Green
- Showy in fall
- No
- Keeps leaves
- No
- Fruit color
- Brown
Other
- Toxicity
- None
- Nitrogen fixation
- None
- Nursery availability
- Routinely Available
- Family
- Poaceae
- PLANTS symbol
- PASM
Source & data date
- Source
- USDA NRCS PLANTS Database: county distribution records, native status and plant characteristics. CC0 (public domain dedication, per the data.gov catalog record).
- Kew’s World Checklist of Vascular Plants (WCVP): native or introduced status by state. CC BY 3.0.
- USGS US-RIIS (ver. 2.0): species listed as introduced are excluded. CC0.
- Citation
- USDA, NRCS. 2026. The PLANTS Database (https://plants.usda.gov, 11/04/2026). National Plant Data Team, Greensboro, NC USA.
- Govaerts R. (ed.) (2026). WCVP: World Checklist of Vascular Plants. Facilitated by the Royal Botanic Gardens, Kew. Data file dated 2026-06-04, http://sftp.kew.org/pub/data-repositories/WCVP/ (retrieved 2026-11-04). Paper: Govaerts R. et al. (2021) The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8, 215.
- Data date
- Retrieved from PLANTS on November 4, 2026; WCVP data file dated June 4, 2026.
- Scope
- Pascopyrum smithii (PLANTS symbol PASM).
- Method
- A species is listed when it is recorded as native to the state in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in the county by USDA PLANTS. Species PLANTS labels both native and introduced are listed separately. Full method · All sources