There are some 250 species of penstemon. Most are native to the West, ranging from Canada into Mexico; some grow on the highest mountains, some in the desert, and others in forest glades, in foothills, on plains. A few are widely available, but most are sold only by specialists. Some of the perennials described here have woody-based stems, while others are herbaceous. Most species have narrowish, pointed leaves; those in basal foliage clump are larger, those on flower stems are smaller. Narrowly bell-shaped, lipped flowers (usually 3/4–1 1/2 in. long) are most commonly seen in bright reds and blues, but they also come in shades from soft pink through salmon and peach to deep rose, lilac, dark purple, white, and, rarely, yellow. Blossoms of some species attract hummingbirds.
Need fast drainage. Species in particular benefit from rock garden conditions. Usually short lived (3 or 4 years). Hybrids and selections tend to be easier to grow than wild species alongside regular garden plants; wild kinds may die quickly if given too-rich soil and too much water. In dry years or with restricted water, however, plants of wild species may thrive.Penstemon digitalis
Native to the eastern and central U.S. grows to 3–5 ft. tall and 2–3 ft. wide, with long, medium green leaves and clusters of white or pale pink flowers in summer. Tolerates heat and humidity. Popular ‘Husker Red’ grows to 2 1/2–3 ft. tall and has maroon foliage and pinkish white flowers.
Native to eastern North America. Grows to 1–1 1/2 ft. tall and about 3 ft. wide. Most useful for...
Grows to 6–8 in. high and 8 in. wide, with smooth, wavy-edged leaves. Purple, pansylike, slender...
Deciduous, from Europe, North Africa, and central Asia. Grows to 8–15 ft. tall and wide, with ar...