Native Plants for the Intermountain West: Plant List

Cardinal Penstemon in the Landscape

Stephen Love, University of Idaho

Scientfic Name:  Penstemon cardinalis
Common Name:  Cardinal Penstemon

Description:  The common and scientific names of this penstemon refer to the deep blood-red color of the flowers. It is a moderately short-lived perennial with a woody crown that dies back to the ground during winter. The plant is fairly tall, usually around 3 feet, and tends to be spreading. Leaves are large, glossy, bright green, and mostly confined to the base of the plant. The flowers are tubular. The bloom period is moderately long, lasting from mid-June into early August. Cardinal penstemon is a good subject for a moderate to large-sized xeric bed, border, or rock garden.

Native Habitat:  Native to New Mexico and west Texas. Grows at elevations of 4,500 to 6,000 feet on limestone or rocky slopes and canyon bottoms among montane scrub consisting mostly of pinyon pine and junipers.

Cultural Requirement

Soil:  Prefers a well-drained calcareous soil. Can tolerate clay soils but is longer-lived in a nutrient-poor, well-drained soil.

Moisture Tolerance:  Marginally tolerant of completely xeric conditions and does best with supplemental water during the driest part of the summer.

Sun/Shade/Preference:  Blooms best in full sun but tolerates part-shade.

Transplanting:  Tolerates transplanting with few losses, both from pot to pot and from pot to garden. Plants grow well in pots up to at least gallon size.

Propagation:  Easy from seed. Also amenable to propagation as rooted cuttings. Basal cuttings from non-flowering stems work best.

Maintenance (pruning, fertilization, deadheading, division, irrigation, etc):  Plants will usually only bloom once and should be dead-headed after bloom to encourage new leaf growth and improve appearance. Deadheading also tends to extend the life of the plants. The plants require periodic irrigation (three to six times each summer) and minimal fertilization.

Insect, disease, or other problems:  Other than occasional root rots when planted in heavy soil, Cardinal penstemon has no serious pest problems.

Landscape Value

Use in the Landscape:  Cardinal penstemon can be effective in numerous applications in a water-conserving garden. It can serve in the role of specimen plant or can effective accent many other plants. Cardinal penstemon is appropriate for berms, large rock gardens, beds, and borders. It is especially effective as a component in parking strip plantings. It can be used in either naturalized or formal designs.

Foliage:  The leaves are large, bright green, glossy, and grow mostly as a low basal mat. Leaves on the flowering stems are smaller and triangular in shape.

Flower:  The dark red flowers grow on long, spreading stems. The flowers are tubular and have inconspicuous lobes around the opening.

Timing:  June - August.

Color:  Red, orange-red.

Fruit:  An upward facing, globular capsule, with sharp, stiff lobes on top. Each capsule holds numerous seeds.

Form:  Open, spreading form.

Texture:  Moderately course.

Ultimate Size:  In bloom – 2 to 3 feet tall; leaf mat – 6 to 8 inches. Width is similar or slightly greater than the height.

Rate of Growth:  Moderately fast. The plants often bloom the first year if established early and provided with good growing conditions. The plants increase in width and number of flowering stems as they age.

Suggested Plant Partners:  Plant cardinal penstemon with plants that provide foliar interest and earlier/later bloom. Suggestions include Artemisia frigida, Hymenoxys acaulis, Eriogonum ovalifolium, Penstemon humilis, Agastache rupestris, Salvia dorrii, Eriogonum niveum, Eriogonum strictum and small to moderate-sized native clump grasses.

Availability:  A few native plant nurseries carry Penstemon cardinalis as potted plants. Seed can be purchased from the American Penstemon Society or from many native plant seed suppliers.

Cultivars:  None, although there are interspecific hybrids derived from this species.


Nold, R. 2008. High and Dry: Gardening with Cold Hardy Dryland Plants. Timber Press, Portland, Oregon.