Polemonium caeruleum
Jacob's ladder
A clump-forming perennial to 90cm tall, with ladder-like, pinnate mid-green leaves composed of leaflets, and stiff stems bearing sprays of blue flowers 2.5cm wide with prominent yellow stamens in early summer; often seeds about rather freely
Synonyms
Polemonium pulchellum Turcz.
Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Moisture
Moist but well–drainedpH
Acid, Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Green | |||
|---|---|---|---|---|
| Summer | Blue | Green | ||
| Autumn | ||||
| Winter |
Position
- Full sun
- Partial shade
Aspect
South–facing or North–facing or West–facing or East–facing
Exposure
Exposed or Sheltered Hardiness
H7Botanical details
- Family
- Polemoniaceae
- Native to GB / Ireland
- Yes
- Foliage
- Deciduous
- Habit
- Clump forming
- Genus
Polemonium can be annuals or herbaceous perennials or upright or spreading habit, with pinnate leaves and usually clustered, tubular, bell, or funnel-shaped flowers
- Name status
Correct
- Plant range
- N Temperate
How to grow
Cultivation
Grow in any fertile, moist but well-drained soil in full sun or partial shade
Propagation
Propagate by seed sown in containers, in a cold frame in autumn or spring, or divide in spring
Suggested planting locations and garden types
- Coastal
- Wildlife gardens
- Wildflower meadow
- City and courtyard gardens
- Cottage and informal garden
- Flower borders and beds
Pruning
No pruning required. Cut back foliage to ground level at the end of the season
Pests
Generally pest-free
Diseases
Powdery mildews can sometimes be a problem
Get involved
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