Polemonium

Polemonium flowers

Attractive hardy annuals and short-lived perennials from northern temperate regions. The leaves are arranged in a series of rung-like leaflets, hence its common name.

Family: Polemoniaceae
Botanical Name: Polemonium (po-lee-mo-nee-um)
Common Names: Jacob's Ladder

Foliage: Deciduous, ladder-like, pinnate green leaves.

Flowers: Sprays of simple open bell-shaped flowers.

Flowering Period: Late spring to summer.

Soil: Moist but well-drained, fertile soil (clay, sand or loam). Acid, alkaline or neutral pH.

Conditions: Full sun or partial shade. Plant in any aspect.

Habit: Bushy, upright or spreading.

Type: Herbaceous perennial.

Origin: North and South America, Asia and Europe.

Hardiness: Hardy in the UK.

Planting and Growing Polemonium

Easy to grow. Thrives in any good free-draining, fertile soil. Add plenty of compost before planting.

Excellent border perennial. Suitable for mixed herbaceous borders and shady woodland edges.

Taking Care of Polemonium

Pruning Polemonium

Deadhead to prolong the flowering season. Tidy up the old foliage in autumn.

Perennials can be short lived, so lift and divide every few years to reinvigorate.

Pests and Diseases

Generally trouble free.

Propagating Polemonium

Divide established clumps when dormant.

Popular Varieties of Polemonium

Polemonium boreale (Northern Jacobs Ladder) is a compact hardy creeping perennial with pinnate green leaves and sky blue flowers. Height and spread to 1ft (30cm). Variety 'Heavenly Habit' bears clusters of violet-blue flowers, each with a distinct golden yellow eye. For sale at Thompson & Morgan.

Polemonium caeruleum produces hummocks of attractive dark-green, fern-like foliage. Strong stems with blue or white flowers, in May-July. Height 1.5-3ft (45-90cm), spread 1.5ft (45cm). For sale at Crocus. Cultivars include:

  • 'Album' white flowers.
  • 'Brise d'Anjou' attractive yellow or cream-edged leaves and mauve flowers.

Polemonium Golden Feathers is an attractive variegated form with bright golden edged foliage. Lavender or lilac coloured flowers appear in spring and last several months. For sale at Suttons.

Polemonium foliosissimum violet, yellow or white flowers. Height to 3ft (90cm),

Polemonium repans low growing spreading form with lilac flowers. Height to 1ft (30cm). Cultivar 'Stairway to Heaven' (PBR) bears distinctive variegated foliage and clusters of light blue to white flowers. For sale at Crocus.