Penstemon

Originating from the United States, penstemons form a bushy clump composed of long, green, evergreen leaves. Just like foxgloves, to which they are closely related, they have tubular flowers in various colours including; pink, violet, yellow, red, white, or burgundy, often maculated or spotted inside the purple or white corolla. They flower abundantly from early summer and continuously until autumn, provided that the faded flower stems are regularly cut. Sun-loving plants par excellence, they thrive in warm and rich, well-draining, rocky or sandy soils and appreciate moisture during their flowering period. While they are very hardy on the coast, elsewhere they should be planted in the warmest and sunniest spots in the garden. A warmer and more sheltered exposure is recommended in colder and wetter regions. Similar to grasses, the stems should be cut back to 15-20cm (6-8in) from the ground in early spring.

Doubtful about their hardiness? The most knowledgeable gardeners always take a few penstemon cuttings in summer and keep them in buckets protected from the cold during winter. This ensures the perenniality of their plants.