Tall and spiky, shrubby and spreading, narrow or broadleaved, plants for hot sun or light shade, penstemons fill the niche. Known as beardtongues, penstemons are ideally suited for Colorado—many are native the West.

A hearty, healthy mob, attracting hummingbirds and butterflies, penstemon species include ground hugging types, small bushy mounds and tall spikes. Leaves may be bluish or bright green, small or large and most are evergreen. Plants are drought tolerant and virtually pest free. Blooming in a rainbow of colors, these beauties will delight the heart of any gardener. The reputation for being short lived is usually because of a zealous gardener’s heavy hand with the hose and soil amendments. Penstemons flourish in loosened gravelly or clay soils with excellent drainage. Resist the urge to amend the soil, water or fertilize heavily. Prompt removal of most seedheads, leaving only one or two to reseed, will also promote longevity.

Bloom begins in mid to late spring with the delicate lavender blue of ground hugging P. procerus. It covers the ground with a substantial glossy mat of bright green leaves. Dainty flowers, lasting almost a month, float about a foot above the foliage. It does best located in front of a bed or edging a pathway.

To attract hordes of acrobatic hummingbirds, plant P.barbatus, scarlet bugler. The brilliant red flowers rise two to three feet above the scant foliage. A native of the plains, P.barbatus flourishes in naturalistic plantings or a dry garden. Exceptional cultivars include ‘Prairie Dusk’ with rose purple flowers on shorter stems, 12-18” tall. Others include ‘Prairie Fire,’ sporting vermillion blossoms on two foot tall stems. Lovely ‘Elfin Pink’ displays salmon pink blooms on 18” stems. ‘Schooley’s Yellow’ blooms from late spring to July for a smashing summer display.

P. pinifolius, pine leaf penstemon, is gorgeous in a rock garden or covering the top of a rock wall. The evergreen needle-like foliage forms a 12” tall shrubby mound. Flowers, though small, are scarlet and cover the mound from June to early September, a remarkable bloom period. Cultivars ‘Mursea Yellow’ and ‘Mango’ are especially striking—try planting them with blue flowers.

The Rocky Mountain native, P. strictus, famous for lusty spires of indigo and purple, covers the ground with lush evergreen foliage. It tolerates dry or irrigated conditions. Floriferous ‘Bandera’ and ‘Rondo,’ with spikes changing from rose to purple, are excellent choices.

Dryland penstemon, P. grandiflorus, sends up masses of foxglove-like lavender, pink or white blossoms from an evergreen rosette of blue-gray foliage. Even showier is the turquoise foliage mound and tall pink blossoms of P.clutei and P. palmeeri. The foothills native, P. secundiflorus, stands a foot tall, awash in lavender “sidebells.” The plant flourishes in unamended soil and hot sunny locations.

Probably the easiest to grow of penstemon species is P. digitalis ‘Husker Red’. It adapts readily to traditional flower border conditions, amended soil, ample moisture and crowded plantings. The white blooms float above large maroon leaves on long red stems. This plant easily coexists with roses, peonies and lilies. Choose plants with the deepest red leaves, as the seedlings can sometimes vary in color.

Whether searching for an adorable shrublet, a groundcover or a showy perennial, you’ll find a least a dozen penstemon varieties at local nurseries. Dryland and rock garden penstemon are best mulched with gravel, promoting reseeding. Just remember to not over-water and not amend the soil.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

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This page updated:  May 30, 2007