Jacob's ladder
Polemonium caeruleum
Also called Polemonium, Greek valerian and Charity
Garden plant · PerennialsCut the whole thing to the ground the moment the first flush is over. It comes back with fresh ladders and often a second flowering, where left alone it just goes to mildew and seeds itself everywhere.
Care at a glance
- Ease
- Easy
- Water
- Every 5 daysWater the ground — water at the base, in the morning, not over the leaves.
- Light
- Sun to part shade
- Feed
- Every 45 days
- Humidity
- Average
- Hardiness
- Very hardy RHS H7, to -25°C
- Size
- 0.7 m tall · 0.4 m across
- Lifecycle
- Perennial
- Origin
- Europe and temperate Asia
Is it safe for pets and people?
PetsNothing recorded against it
No animal-poison authority lists this plant either way.
PeopleNot checked yet
Nobody has checked this one against a source for us yet, so treat it as unknown rather than safe.
Checked against ASPCA and RHS on 2026-09-22. Where a source says nothing, we say nothing.
A guide, not veterinary or medical advice. If a pet or a person has eaten a plant and you are worried, call your vet or doctor now — don’t wait for signs to appear. Spotted a mistake? Tell us.
First signs of trouble
- The ladder leaves go grey-white from the bottom of the plant upwards in July, and the rungs curl in on themselves. It is the commonest thing to happen to this plant and cutting it to the ground fixes it.Powdery mildew · disease
- Small brown rounds with a paler ring, one or two per leaflet, on the shaded lower ladders after a wet fortnight.Leaf spot · disease