Description
Form: Herbaceous stems on a woody base (subshrub).
Lifespan: Perennial.
Leaf retention: Evergreen to 28°F (-2.2°C) if protected from wind.
Growth rate: Moderate to rapid.
Mature Size: 12-18" (30-46cm) high and 6-12" (15-30cm) wide.
Flowers: Cherry-red to pink, may be whitish inside, tubular, in clustered spikes.
Bloom: Spring into fall. For some cultivars, a single plant may bloom up to four months in favorable conditions.
Fruit: A seed capsule containing tiny seeds.
Leaves: Glossy green, thick, oval with small-toothed margins on the lower stem and lance-shaped with smooth margins on the upper stem. The leaves may turn purple in cold weather.
Stems: Stiff, upright to leaning.
Roots: The entire root area needs all day shade, especially afternoon shade.
Wildlife: The flowers attract hummingbirds when the plant is located more than three feet above the ground. The foliage is browsed by rabbits and deer.
Toxic / Danger: No.
Origin: Texas and Mexico.

Cultivation and Uses
USDA hardiness zones: 8-10. This plant dies to the ground below 28°F (-2.2°C) but is root hardy to 10°F (-12.2°C). Provide winter wind protection in regions with freezes.
Heat tolerant: Yes.
Drought tolerant: Yes.
Sun: Rock Penstemon likes its head in the sun and its feet in the shade. Provide full morning sun with part afternoon shade for the leaves and flowers. Provide all-day shade for the roots.
Planting: Locate this plant where it receives afternoon part shade with a shaded root area. It must be protected from rabbits; 18" (46cm) high fencing is typically used. It can be grown on the top of a 4-6' (1.2-1.8m) high wall or pedestal to provide better protection for visiting hummingbirds as well as to exclude rabbits. Growing out of a well-draining hole in the side of a wall can mimic its growing conditions in the wild.
Soil: Very well draining, dry, low organic material, ph 6.1-7.8 (slightly acidic to slightly alkaline). Do not fertilize.
Water once established: Once or twice a month. This plant is susceptible to root rot. Do not overwater.
Mulch: Use inorganic mulch such as decomposed granite or tightly packed large gravel. Always shade the roots from the sun.
First Year Care: The soil must dry between waterings. This plant can be slow to establish. It may not bloom until the second year even when transplanted from a pot.
Prune: After the last freeze, remove winter damage or cut it nearly to the ground. In regions without freezes, cutting the plant lower in late winter will encourage more growth.
Litter: Low.
Propagation: Seed planted in the fall; cuttings of new growth taken in the spring.
Uses: Ornamental, hummingbird garden, rock garden, low water (xeriscape) garden.

Comments
Rock Penstemon is a member of the Penstemon and Plantain family (Plantaginaceae). It can be found growing in steep rock faces in the wild. This is one of the easiest to grow penstemons for desert regions when it is in a well draining, afternoon part-shaded location.

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