Jacob’s ladder
These plants are clump forming perennials growing to about 18-24in in height which form dense mounds of foliage with pinnate leaves and numerous leaflets on erect stems. They flower in profusion in late spring or early summer with bell or saucer shaped flowers in terminal or auxiliary cymes. These are plants for the herbaceous border which give the appearance of perhaps being tender but are actually perfectly hardy.
They grow well in both partial shade or full sun in moist but well drained soil and regular deadheading will prolong the flowering season. Clumps can be divided when dormant and the seed can be sown in the greenhouse in the spring.
P. ‘Northern Lights’ has scented lilac-blue flowers above a mound of green finely cut foliage.
P. reptans ‘Stairway to Heaven’ has variegated foliage which is cream and green but flushed with pink in late spring as the new growth develops. The fragrant flowers are pale blue.
