Rocky Mountain Beardtongue (Penstemon)

Rocky Mountain beardtongue (Penstemon strictus) is an evergreen perennial with several upright flower spikes above a low foliage mat. The Lady Bird Johnson Wildflower Center describes royal-blue to purple flowers, a height of 1–3 feet, May–June bloom, and special value to native bees. ([Lady Bird Johnson Wildflower Center](https://www.wildflower.org/plants/result.php?id_plant=PEST2)) ## Appearance This western North American native grows in subalpine and valley sagebrush and conifer-forest habitats. Its tubular blue-to-purple flowers rise in multiple spikes above green leaves; the species is listed as evergreen and generally reaches no more than about three feet tall. The flower display is strongest in spring, commonly May and June. ([Lady Bird Johnson Wildflower Center](https://www.wildflower.org/plants/result.php?id_plant=PEST2)) ## Growing conditions Plant it in part shade and sandy or rocky soil that drains well. Although it tolerates heavier soils and more moisture than many penstemons, the Wildflower Center says it prefers dry, light, well-drained ground and rates its water use low. Its native range includes Arizona, Colorado, New Mexico, Utah, and Wyoming. ([Lady Bird Johnson Wildflower Center](https://www.wildflower.org/plants/result.php?id_plant=PEST2)) ## Maintenance Water sparingly after establishment and avoid persistently wet soil. Seed propagation is usual; the Wildflower Center recommends barely covering seed in fall and notes that cold-moist stratification for two to three months improves germination. Root division is another option in early spring, with at least one bud on each division. Rocky Mountain beardtongue has special value to native bees, so leave some flower stems through bloom before tidying the plant. ([Lady Bird Johnson Wildflower Center](https://www.wildflower.org/plants/result.php?id_plant=PEST2))