There are some 250 species of penstemon. Most are native to the West, ranging from Canada into Mexico; some grow on highest mountains, some in the desert, 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 smaller.Narrowly bell-shaped, lipped flowers (usually 3/4 to 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 barbatus
Needs some winter chill for best performance. Native to mountain regions from Colorado and Utah south to Mexico. Open, somewhatsprawling habit to 3 ft. or higher, 1 1/2 ft. wide. Bright green foliage. Long, loose spikes of red flowers over a long period, starting in late spring or midsummer. One of the best penstemons for humid-summer areas. Look for foot-tall hybrid ‘Elfin Pink’, with clear pink flowers; 2 1/2-ft. hybrid ‘Rose Elf’, with deep rose blooms; and 2-ft. variety ‘Schooley’s Yellow’, with soft lemon yellow flowers.Penstemon cardinalis
Native to southern NewMexico and Texas. Leafy habitto 2 1/2 ft. high, 2 ft. wide. Large, leathery, dark green foliage. Dark red flowers bloom all summer; very popular with hummingbirds. Long-lived, adaptable plant that thrives even in areas with humid summers.Penstemon centranthifolius
Native to Coast Ranges of California. To 2– 3 ft. tall,1 1/2–2 ft. wide, with waxy gray leaves that vary from lance shaped to oval. Long spikes of narrow bright red flowers in spring or early summer.
Native to eastern and central U.S. To 3–5 ft. tall, 2–3 ft.wide,with long, medium green leaves and clusters of white or pale pink flowers in summer. Tolerates heat and humidity.Penstemon eatonii
Native to mountains of desert Southwest. This scarlet-flowered species is similar to P. centranthifolius. Grows 1–3 ft. tall and wide and has lance-shaped, leathery green leaves, sometimes with a whitish bloom (but without a waxy coating). Flowers appear on tall spikes in spring to early summer. Tolerates heat.
California native of variable appearance, with glossy bluish green foliage and crowded spikes of narrow blossoms ranging from reddish purple to deep blue. Usually grows 1 1/2-2 ft. high and 2-3 ft. wide. Blooms in spring and early summer.
Perennials in Zones 6–9, 14–24; treated as annuals elsewhere (grow as a winter annual in Zones 12, 13). All are compact, bushy, upright plants to 2–4 ft. tall and 3 ft. wide, with narrow green leaves. Large (to 2-in.) summer flowers in loose spikes at stem ends, in almost all colors but blue and yellow. Mass these plants in borders or group with other summer-flowering plants. Where grown as perennials, set out nursery transplants in fall for bloom in late spring and early summer. After the flowers fade, cut back to side growth for another round of bloom in late summer, early fall. This group of penstemons prefers regular water but is subject to root rot in wet, heavy soils.
Native from Arizona into Mexico. To 2–4 ft. tall and 1–3 ft.wide,with leathery gray-green leaves .Many flower stalks bear reddish pink blossoms in spring. Self-sows.Penstemon pinifolius
Native to southern New Mexico and Arizona. Woody-based growth to 1 1/2ft. high, 2 ft.wide, with short, needlelike bright green leaves crowded along stems. Red-orange summer flowers. For rock garden, border, small-scale ground cover. Good in dry gardens or regularly watered ones.Penstemon pseudospectabilis
Native to mountains of Southern California and Arizona. Shrubby, upright plant 2–4 ft. tall, 2 ft. wide. Large bluish green leaves with bases that clasp the stems. Rosy pink to purple flowers from spring into summer.Penstemon rupicola
Native to Cascades and Siskiyou Mountains. Woody-based growth to 4 in. high, 1 1/2 ft. wide, with trailing, much-branched stems. Small, roundish blue-green leaves have finely toothed edges. Bright rose flowers bloom from late spring into summer. Beautiful in rock gardens or chinks in dry stone wallsPenstemon spectabilis
Native to Southern California. To 3–4 1/2 ft. tall and wide,with smooth green or grayish leaves that clasp the stems. Rose-colored to purplish flowers in spring, early summer.Penstemon strictus
Native from southern Wyoming to Arizona and New Mexico. To 2–3 ft. tall, 2 ft.wide. Dark green leaves turn purplish in winter. Blooms in early summer, producing large blossoms in near-violet to brilliant bluish purple. Long lived and adaptable.
There are some 250 species of penstemon. Most are native to the West, ranging from Canada into Mexico;...
Blooms in midsummer,with slightly branched, 3 1/2-ft. stems bearing 3-in., brightreddish apricot flowe...
Native to coastal Southern California. The two similar forms described below are both useful as small ...