About
Penstemon rupicola, the rock penstemon, is a creeping, dwarf, evergreen sub-shrub to 6 cm with small, rounded, glaucous leaves and tubular, two-lipped, rosy-pink flowers 3 cm long opening from late spring. A beautiful and rewarding penstemon for a sunny, well-drained rock garden or stone wall.
About the genus
Penstemon are deciduous or evergreen perennials or subshrubs with simple, narrow leaves and racemes or panicles of tubular, bell-shaped or funnel-shaped flowers in summer and early autumn, in shades of red, pink, purple, white and bicolours. Excellent plants for sunny, well-drained borders.
Growing conditions
SunlightFull sun, Partial shade
Soil typeChalk, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureWell-drained
AspectSouth-facing, West-facing, North-facing, East-facing
ExposureExposed, Sheltered
UK hardinessH5
Plant details
Plant typeShrubs
HabitMatforming
FoliageEvergreen
HeightUp to 10 cm
Spread0.1-0.5 metres
Time to full height5-10 years
Suggested usesPatio and container plants, Rock garden, Gravel garden, City and courtyard gardens, Coastal, Cottage and informal garden, Wildlife gardens
Native toW North America
Care notes
CultivationGrow in poor to moderately fertile, very gritty, well-drained soil in full sun. In cold areas, protect plant overwinter with a dry winter mulch. See penstemon cultivation for further advice The plant illustrated here is the cultivar 'Diamond Lake'
PruningDeadhead after flowering to maintain vigour. Then cut back to base in early spring
PropagationPropagate by seed
Pest resistanceMay be susceptible to slugs, snails, glasshouse red spider mite, and leaf and bud eelworms
Disease resistanceGenerally disease-free