Penstemon heterophyllus 'Catherine de la Mare

Penstemon ''Catherine de la Mare' is an upright perennial to 50cm tall, with lance-shaped leaves and  clusters of small bell-shaped purple blue tubular flowers.  This hardy semi evergreen evergreen plant is best left until early spring after the risk of harsh frosts has passed before pruning back any dead stems and excess growth, although can be pruned by a third in early autumn if likely to be damaged by winter winds.    Will tolerate any well drained soil, in sun or part shade.  In colder areas protect with a dry mulch in winter.