About
Polemonium caeruleum, Jacob's ladder, is a clump-forming perennial to 90 cm with ladder-like, pinnate, mid-green leaves and stiff stems bearing sprays of blue flowers 2.5 cm wide with prominent yellow stamens in early summer; it often seeds about freely. An ornamental and rewarding native for a sunny, moist border.
About the genus
Polemonium, Jacob's ladders, are annuals or herbaceous perennials with pinnate, ladder-like leaves and clusters of tubular, bell- or funnel-shaped flowers in blue, violet, pink or white from late spring to summer. Rewarding and reliable border plants.
Growing conditions
SunlightFull sun, Partial shade
Soil typeClay, Loam, Sand
Soil pHAcid, Alkaline, Neutral
Soil moistureMoist but well-drained
AspectSouth-facing, North-facing, West-facing, East-facing
ExposureExposed, Sheltered
UK hardinessH7
Plant details
Plant typeHerbaceous Perennial
HabitClump forming
FoliageDeciduous
Height0.5-1 metres
Spread0.1-0.5 metres
Time to full height2-5 years
Suggested usesCoastal, Wildlife gardens, Wildflower meadow, City and courtyard gardens, Cottage and informal garden
Native toTemperate Eurasia
Care notes
CultivationGrow in any fertile, moist but well-drained soil in full sun or partial shade
PruningNo pruning required. Cut back foliage to ground level at the end of the season
PropagationPropagate by seed sown in containers, in a cold frame in autumn or spring, or divide in spring
Pest resistanceGenerally pest-free
Disease resistancePowdery mildews can sometimes be a problem