Also known as Blue Jacob's Ladder · Blue Polemonium · Blue Valerian
Jacob's Ladder (Polemonium caeruleum) is a perennial wildflower producing clusters of sky-blue, star-shaped flowers atop upright stems. Ideal for cottage gardens and shad
At-a-glance light, water, soil, and growing conditions from plant data
Moderate
50% intensity
Thrives in full sun to partial shade. Protect from intense afternoon sun in hot climates.
Moderate
50% intensity
Prefers consistently moist soil, but avoid waterlogging.
Well-drained
50% intensity
Moderate
50% intensity
Prefers cool to moderate temperatures. Hardy in many climates.
Low
25% intensity
Benefits from a light feeding in spring; avoid over-fertilizing.
Safety information from plant toxicity data
| Attribute | Value |
|---|---|
| Toxic for humans | No 0/5 intensity |
| Toxic for pets | No 0/5 intensity |
Key traits and growing stats from plant data
Watering, pruning, propagation, and repotting details from plant data
Keep the soil consistently moist but not waterlogged during the growing season. Water deeply when the top inch of soil feels dry.
Reduce watering in autumn and winter, allowing the soil to dry out slightly between waterings to prevent root rot.
Deadhead spent flowers to encourage further blooming and prevent self-seeding. In late autumn or early spring, cut back the old foliage to the ground.
This tidies the plant and promotes healthy new growth for the coming season.
Jacob's Ladder is easily propagated from seed sown in autumn or early spring, or by division in spring. Seeds may require a period of cold stratification.
Divisions should be replanted promptly and kept moist until established.
Established plants generally do not require frequent repotting. If container-grown, repot every 2-3 years in spring. Choose a pot only slightly larger than the current one with fresh, well-draining potting mix.
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Monthly activity intensity for bloom and fruit across both hemispheres.
Flowering & fruiting calendar
Flowering & fruiting calendar
Photos of Jacob's Ladder (Polemonium caeruleum)
Where Jacob's Ladder (Polemonium caeruleum) is found
Density
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Common names and botanical synonyms
Botanical classification
| Rank | Name |
|---|---|
| Kingdom | Plantae |
| Division | Tracheophyta |
| Class | Magnoliopsida |
| Order | Ericales |
| Family | Polemoniaceae |
| Genus | Polemonium |
| Species | Polemonium caeruleum |
Similar in genus Polemonium
Answers based on plant encyclopedia data
