Specialist penstemons

These compact, usually evergreen subshrubs and alpines vary from upright to more spreading, prostrate or mat-forming plants. Tubular white, pink, red, blue or yellow flowers are borne over several weeks. Examples are Penstemon fruticosus var. scouleri 'Albus', Penstemon newberryi and Penstemon rupicola.

These more specialist penstemons must have free-draining, ideally gritty soil in full sun. They can do well in poor soil. In cold areas, they appreciate the protection of being planted at the base of a warm wall. A gravel garden, scree or rock garden would be perfect.

Plants will not do well in heavy, wet soil and will not flower in shade.

To keep plants compact and productive, shorten stems immediately after flowering. Delay pruning of late-summer-flowering types until early spring.