by Diane Engles, HAS Trustee
If you are looking to plant more water-wise and pollinator-friendly perennials this spring, a top contender is the penstemon. This North American native plant produces colorful tubular flared blooms on vertical flower spikes — perfect feeding stations for hummingbirds and other pollinators. The shape and color of the leaves vary depending on the cultivar. They can be oval, lance-shaped or needlelike with colors ranging from green or blue-green to deep purple. Penstemons are related to foxgloves and snapdragons as is evidenced by the similarity of their blossoms. There are over 250 species of penstemons native to the U.S. and over 800 cultivars and hybrids.
“Penstemon” is derived from the Greek words penta and stemon, referring to the flower’s five stamens, four of which are fertile and one sterile. They are also known as beardtongues due to the pollen-free stamen (or staminode) which protrudes from the flower and is covered by small hairs.Penstemons are long blooming and do well in a drier climate such as ours. They are especially happy in loose gravelly soil with good drainage. Penstemons tend to bloom in early summer just after the spring bloomers have faded. They come in sizes ranging from dwarfs that tuck nicely into rock gardens, to waist-high plants that can bring color and movement to the back of the border. They have a broad palette of colors ranging from soft pinks, lavenders and yellows, through more intense shades of violet, rose, and orange, as well as being known for electrifying reds and blues. Deadheading can result in a second flush of bloom, but leave one or two stems to set seed as penstemons are short-lived compared to other perennials.
Pineleaf Penstemon (P. pinifolius) comes in orange and yellow and is one of the shorter penstemons. The older variety is a vivid orange-red, and there is a yellow variety called “Mersea Yellow”. Pineleaf Penstemons have green needle-like foliage with loose spires of blossoms reaching about 10-12 inches in height. Plant Select® has introduced a variety called SteppeSuns™ Sunset Glow. Plant Select® describes it as: “This selection is more than 20 years in the making with each clone and generation an improvement in color and plant size. SteppeSuns™ Sunset Glow is a warming orange color that blooms for a very long season.”
Rocky Mountain Penstemon (Penstemon strictus ) is hardy to Zone 4. Native to Wyoming, Utah and western Colorado, it thrives in rocky or gravelly soil but will adapt to others. One of the longer-lived varieties, it has a basal mat of rounded green foliage with bright blue blooms rising 2-3 feet tall. I first saw it growing in the wild and was delighted to find it will adapt to life in a garden.
Palmer’s Penstemon (Penstemon palmeri) is a tall penstemon hardy to Zone 5. One of the few fragrant penstemons, It has gray green foliage topped in early summer by honey-scented light pink flowers on spikes 4-5 feet tall. Native to southern California, Arizona and Utah, it thrives in arid climates and dry, sandy or gravelly soils. It will not tolerate clay.
Carolyn’s Hope Penstemon (Penstemon x Mexicali) is a lovely pink and hardy to Zone 4. It is a Plant Select® variety, a hybrid between Mexican and American wild penstemons. Carolyn’s Hope was developed in Colorado for the purpose of raising funds to support breast cancer research at the University of Colorado Cancer Center. It is of medium height, 14-18 inches tall and 12-15 inches wide. Cheerful pink, white-throated tubular flowers and dark pink buds rise above narrow, glossy green foliage and are attractive nearly all summer long. Deadhead in order to prolong bloom. Seedlings are often not true to variety color, so pull (if desired).
If you want to dive deeper into the world of penstemons, you can check out the American Penstemon Society. This organization was founded in 1946 and continues their mission of studying, hybridizing and exchanging seed among members today.