Perennial of the Month-- June 2005 

(pole-uh-mO' knee-um) (pronunciation at link, turn up volume if too low)

Common name: Purple-leaved Jacob's Ladder

Family: Polemoniaceae, Polemonium

Height x width: 24" x 12"

Growth rate; habit: moderate, upright

Foliage: alternate, odd-pinnate compound leaves, 20-30 leaves, mainly basal to about 8in. high, basal leaves 3-5in. long,  smaller up the stem; arranged ladder-like (hence the name) up stems; purplish-tinted, especially in spring and fall, and more so in high light

Flowers: fragrant, cobalt blue, cup-shaped flowers in terminal clusters (cymes) in late spring (south), early summer (north); purple flower stems 15-18in. tall

Hardiness: USDA zones (3?) 4-8

Soil: well-drained, average to moderately moist; don't allow to dry out

Light: part shade to full sun north (and if moist), part shade to shade south

Pests and problems: none serious, leaf tips may scorch if too much sun or too dry, leaf spots and powdery mildew may be a problem in the south; foliage tends to decline later in summer; possible slug damage

Landscape habit, uses: borders, woodland gardens, shade gardens, cottage gardens; combines well with white variegated Jacob's ladder cultivars such as Snow and Sapphires, low golden or variegated ornamental grasses or other plants such  as variegated bugloss (Brunnera) cultivars

Other interest: one of darkest purple, showiest, and hardiest cultivars in Vermont trials; named for the biblical reference to Jacob; this cultivar selected by Adrian Bloom in 1996, introduced at the Chelsea flower show in 2002.

Other culture: may cut back to basal foliage after bloom for tidiness, and to encourage late summer rebloom

Propagation: commercially from Blooms of Bressingham licensed propagators as patented, at home by division

Sources: many specialty perennial nurseries, including those Blooms retailers