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Penstemon cardwellii

Native to open, rocky slopes of the western Cascades and Columbia River Gorge in Oregon and Washington, this shrubby, ground-spreading Penstemon bears blue-violet to purple tubular flowers, stems that root at nodes, blooms May–Aug, thrives in well-drained rocky soils with full sun to light shade, and attracts pollinators.

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Common Names

Cardwell's Penstemon, Cardwell's Beardtongue

Summary

Cardwell's beardtongue is a Pacific Northwest native perennial forming cushions with spreading, rooting stems, growing about 4–12 inches tall and 12–15 inches wide, with opposite elliptic to oblong leaves; flowers are blue-violet to purple, arranged in a raceme at stem tips from late spring to early summer, producing a distinctive bloom that attracts pollinators.

Prefers full sun to light shade and well-drained rocky soils; drought-tolerant once established; water regularly after installation but avoid overwatering; propagates by woody stem cuttings or seeds; suitable for rock gardens and borders in appropriate climates and valued for pollinator attraction.

Lifecycle

Perennial

Height

4-12 inches

Spread

12-15 inches

Hardiness Zones

Zones 5a-9b

Sunlight Requirements

Ideally full sun to partial shade.

Soil Type

Rocky, well-drained soil

Soil Drainage

Well-drained soils.

Soil pH

6.6-7.0

Bloom Color

Blue-violet to purple

Bloom Time

Spring and Summer

Foliage Color

Green

Fall Foliage Color

Green

Leaf Lifecycle

Evergreen broadleaf

Growth Rate

Moderate, about 12–24 inches per year.

Seasons of Interest

Spring and Summer

Propagation Methods

Seeds, Cuttings, Layering

Attracts Wildlife

Attracts bees and hummingbirds

Taxonomy

Taxonomic Rank
Species
Author
Howell
Publication
Fl. N.W. Amer. : 510 (1901)

Superior Taxa

Kingdom
Plantae
Subkingdom
Pteridobiotina
Phylum
Angiosperms
Order
Lamiales
Family
Plantaginaceae
Genus
Penstemon

Synonyms

Penstemon fruticosus subsp. cardwellii

References

Penstemon cardwellii Howell | Plants of the World …. powo.science.kew.org.
Cardwell's Beardtongue, Cardwell's Penstemon - Pau…. science.halleyhosting.com.
Penstemon cardwellii Howell — The Plant List. theplantlist.org.
PlantFiles: The Largest Plant Identification Refer…. davesgarden.com.
Penstemon - cardwellii. depts.washington.edu.
Penstemon cardwellii - FNA. dev.floranorthamerica.org.
Everything You Need to Know About Cardwell's Penst…. greg.app.
Penstemon cardwellii. hardy-plant.org.uk.
Intermountain Herbaria Portal - Penstemon cardwell…. intermountainbiota.org.
Penstemon cardwellii - Plant Lust. plantlust.com.
Penstemon cardwellii - Sevenoaks Native Nursery. sevenoaksnativenursery.com.
Penstemon cardwellii. species.data.kew.org.
Penstemon cardwellii. species.wikimedia.org.
Penstemon cardwellii - Trees and Shrubs Online. treesandshrubsonline.org.
Penstemon cardwellii | Cardwell's penstemon. wildflowersearch.org.
Penstemon cardwellii | International Plant Names I…. ipni.org.
Penstemon cardwellii, Cardwell's Penstemon - Kiona…. kionanativeplants.com.
Penstemon cardwellii | Cardwell's Penstemon. pnwflowers.com.
Penstemon cardwellii | /RHS. rhs.org.uk.
Penstemon cardwellii (Cardwell's beardtongue) | Na…. wildflower.org.
Penstemon cardwellii. wnps.org.
World Flora Online. worldfloraonline.org. June 2024.