Subscribe Today
Give a Gift
Customer Service

Phoenix Home and Garden
Subscribe Today!
For the HomeFor the GardenFood & EntertainingResourcesArticle Archive
For The Garden

All-Purpose Penstemons

Author: Cathy Cromell
Issue: February, 2013, Page 122
Photo by Richard Maack

Desert Gardening 101

Whatever your gardening conditions or skill level, there surely is a penstemon that will thrive in your locale. Dozens of these wildflower species grow naturally across Arizona and the Southwest, in habitat as diverse as arid deserts, rocky cliffs and canyons, moist meadows, sandy grasslands and coniferous mountains. There’s even a rosy-pink penstemon (P. clutei) endemic (growing nowhere else in nature) to Sunset Crater Volcano National Monument north of Flagstaff.

Penstemons can perform just about any landscape role imaginable. They provide a showy blast of color to xeriscapes; blend seamlessly with grasses and other wildflowers in meadows; naturalize across slopes and disturbed soil; border paths and flower beds; tuck neatly into rock gardens and around swimming pools; and even tolerate containers (if not over-watered).

Although a few small bush species exist, most penstemons are herbaceous perennials, producing low-growing foliage that does double-duty as an evergreen groundcover in the low desert.

Despite these varied uses, penstemons are most often planted to attract hummingbirds. The tiny iridescent flyers patrol penstemons relentlessly, drawn to tubular flowers that fit the birds’ long, narrow bills.

The key to penstemon success is excellent soil drainage with minimal water. They like gravely soil and will rot with wet feet. They take full sun to partial shade, although they do benefit from filtered light during intense summer afternoon sun and reflected heat.

While penstemons may have a short life span, most self-sow prolifically. Allow seeds to dry on the flower stalk and scatter for a never-ending supply of plants. Transplant excess seedlings where you wish. You can also save seeds to sow in autumn.

Start with scarlet Eaton’s firecracker (P. eatonii) and hot-pink Parry’s penstemon (P. parryi), which provide big rewards of intense color and guaranteed hummingbird visits. Both are found naturally across a broad elevation range, thus tolerate varied growing conditions (Eaton’s: 2,000-7,500 feet; Parry’s: 1,000-5,000 feet), germinate easily from seed and self-sow like gangbusters.

In the low desert, Eaton’s firecracker starts flowering in late winter and Parry’s joins the color fest in spring. (Bloom periods are later at higher elevations.) Expand your penstemon collection to extend your bloom season and keep the nectar flowing. The more reliable the food source, the more likely hummingbirds will stay, perhaps to nest in your yard. Coral penstemon (P. superbus) blooms in late spring and rock penstemon (P. baccharifolius) flowers in late spring to late summer.

Penstemons that thrive in the low desert display flowers in the pink-orange-red spectrum. Higher-elevation gardeners can add lavender-blue-purple to the palette, such as Rocky Mountain penstemon (P. strictus) (6,000-10,000 feet), which, unlike most of its relatives, tolerates soil moisture. Narrow leaf or mat penstemon (P. linarioides) (4,000-9,000 feet ) grows fewer than 12 inches high and spreads like a groundcover.
Subscribe Today!