The intense blue flowers that have a tinge of purple that contrasts beautifully with silvery green foliage. From June to October you will have a fantastic display all summer long. These plants are resilient and weather resistant, and will withstand unpredictable British weather. Grow penstemon in a sunny or semi shaded position on fertile, well-drained soil. Penstemons can tolerate dry soils once established but dislike heavy soils that are particularly cold and wet in winter. Improve heavy soils by adding plenty of coarse grit prior to planting. Feed and water penstemons regularly until they are fully established. Once established they are reasonably tolerant of drought and will require little maintenance. Deadhead faded penstemon flowers to maintain the plant's vigour and encourage further blooms to be produced. In cold areas apply a dry mulch of bark chips of straw around the crown of each plant in autumn. Leave the old foliage intact until spring to protect plants during winter. Pr