Common Name: foothill penstemon
Type: Herbaceous perennial
Family: Plantaginaceae
Zone: 6 to 10
Height: 1.00 to 1.50 feet
Spread: 1.00 to 1.50 feet
Bloom Time: May to July
Bloom Description: Gentian blue
Sun: Full sun
Water: Dry to medium
Maintenance: Low
Flower: Showy
Attracts: Hummingbirds, Butterflies
Tolerate: Deer, Dry Soil, Shallow-Rocky Soil
Culture
Easily grown in average, dry to medium, well-drained soils in full sun. Avoid wet, poorly-drained soils. Remove spent flowering racemes to prolong bloom. Plants may be cut back after flowering to improve appearance of the planting. This plant may not be reliably winter hardy in the St. Louis area where it should be planted in a protected location.
Noteworthy Characteristics
Penstemon heterophyllus, commonly called foothill penstemon, is native to hillsides, grasslands, chaparral and open forest areas in the foothills of California mountain ranges at elevations below 5500’. It is a clump-forming perennial that features loose terminal racemes of gentain blue, tubular flowers (to 1.5” long) atop erect spreading stems to 18” tall. Flowers bloom in late spring to summer. Narrow, lance-shaped to linear, medium green stem leaves (to 2-4” long). The blooms are attractive to hummingbirds, butterflies, and other insect pollinators.
Genus name comes from the Greek words penta meaning five and stemon meaning stamen in reference to each flower having five stamens (four are fertile and one is sterile).
Specific epithet means diversely leaved.
Penstemons are sometimes commonly called beardtongues because the sterile stamen has a tuft of small hairs.
‘Electric Blue’ features intense blue flowers that are typically a more uniform blue than the species.
Problems
No serious insect or disease problems. Root rot can occur in wet, poorly-drained soils. Leaf spot may also occur.
Uses
Sunny areas of borders, rock gardens or native plant gardens. Good on dry, rocky slopes or hillsides. Suitable for use in containers.