These shade-loving perennials form lush rosettes of finely divided, ferny, typically light to medium green foliage; clusters of bell-shaped flowers appear in spring or early summer. Good under trees. Lovely in combination with bellflower (Campanula), bleeding heart (Laprocapnos), ferns, hellebore, hosta, lilies. Grow from seed or from divisions made after bloom or in spring; give well-drained soil. The following species and hybrids are among those most commonly available in nurseries.
P. caeruleum. JACOB'S LADDER. Native to Europe and Asia. Fairly upright-growing plant to 13 ft. high, 11 ft. wide. Lavender-blue, pendulous, inch-wide flowers. 'Brise d'Anjou', with each leaflet neatly outlined in white, is one of the most striking variegated-foliage plants.
P. reptans. CREEPING JACOB'S LADDER. Native from New Hampshire to Georgia, west to Minnesota, Oklahoma, and Alabama. Weak-stemmed plant to 11 ft. high, 1 ft. wide; light blue, -in. flowers. Better known than the species is heavy-blooming 'Blue Pearl'; it grows 10 in. high, 1 ft. wide and bears bright blue blossoms. 'Firmament' grows to 20 in. high, 1 ft. wide, with bright blue flowers. 'Stairway To Heaven' has leaves edged in white and light blue flowers. 'Touch of Class' is similar but is a little more vigorous. Good in shaded borders and rock gardens.