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Penstemon rupicola

Rock Penstemon
Scrophulariaceae
Perennials

PENSTEMON

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 rupicola

Native to the Cascades and Siskiyou Mountains. Woody-based growth to 4 in. high and 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 walls.

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