Wildflower (forb) · Scrophulariaceae
Mountain blue penstemon
Penstemon laetus
Mountain blue penstemon is recorded as native to 2 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 31 counties of those states by USDA PLANTS.
Key facts · USDA PLANTS
Mountain blue penstemon at a glance
- Native in
- 31 counties, across 2 states and territories
- Estimated cold hardiness
- Zone 8b PLANTS minimum temperature 12°F
- Mature height
- 2.5 ft PLANTS mature height
- Light and water
- Full sun (shade-intolerant) Medium water use
Estimated cold hardiness: zone 8b. PLANTS gives a minimum temperature of 12°F; zone 8b winters bottom out at 15°F, the coldest half-zone that stays within that limit.
Mountain blue penstemon is recorded as native to 2 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 31 counties of those states by USDA PLANTS.
Counties where it is native
The 15 counties with the most ZIP codes among the 31 where it is listed.
Native counties by state
- California 24 counties
- Oregon 7 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
- Forb/herb, Subshrub
- Duration
- Perennial
- Mature height
- 2.5 ft
- Growth rate
- Moderate
- Growth form
- Single Crown
- Shape
- Erect
- Lifespan
- Long
- Active growth period
- Spring and Summer
Light and water
- Shade tolerance
- Intolerant (full sun (shade-intolerant))
- Moisture use
- Medium water use
- Drought tolerance
- High
- Tolerance of waterlogged soil
- None
- Precipitation range
- 12 to 20 in per year
Soil
- Soil textures
- Coarse and medium
- pH range
- 6 to 7.6
- Lime (CaCO₃) tolerance
- Medium
- Salinity tolerance
- None
- Fertility requirement
- Medium
- Minimum root depth
- 12 in
Climate
- Minimum temperature
- 12°F
- Estimated cold hardiness
- Zone 8b and warmer
- Minimum frost-free days
- 150
- Fire tolerance
- Medium
Flowers, leaves and fruit
- Flower color
- Blue
- Showy flowers
- Yes
- Bloom period
- Late Spring
- Foliage color
- Gray-Green
- Showy in fall
- No
- Keeps leaves
- No
- Fruit color
- Brown
Other
- Toxicity
- None
- Nitrogen fixation
- None
- Nursery availability
- Contracting Only
- Family
- Scrophulariaceae
- PLANTS symbol
- PELA7
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
- Penstemon laetus (PLANTS symbol PELA7).
- 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