Photo credits and licenses
Real photographs from naturalists and photographers worldwide, each used under its own license. Credit: Photo by Rose Zappa / iNaturalist (CC BY), Photo by Rose Zappa / iNaturalist (CC BY), Photo by Andrew St. Paul / iNaturalist (CC BY) and Photo by Andrew St. Paul / iNaturalist (CC BY). How photos are sourced →
Jacob's Ladder
Polemonium
Also called greek valerian
Also comes in white.
Jacob's Ladder blooms from May through June.
Mature size, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not.
Growing Jacob's Ladder
Plant it in part shade. It prefers moderate water. It is hardy in USDA zones 3–7. Expect it to reach about 1.6 ft tall and 1.3 ft wide at maturity, in roughly 2 years.
When to plant Jacob's Ladder
Plant Jacob's Ladder in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. For the middle of its hardy zones 3 to 7 range, spring means April to June and fall means August or September. Once settled, it blooms from May to June.
Month-by-month timing for your zone is on the planting calendar: for the middle of its range, start with zone 5 in April.
Good to know about Jacob's Ladder
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Worth knowing
No extension source rates it toxic, and the 'Jacob's Ladder' entry in pet-poison databases is actually an unrelated plant, Smilax, not this one. per NC State and USDA
Two plants, one name
'Jacob's Ladder' covers two plants: North American native Polemonium reptans and the Eurasian garden species P. caeruleum. For native or pollinator value, choose reptans. per NC State and Missouri Botanical Garden
Dislikes heat and humidity
It fails in hot, humid summers; heat plus dry soil scorches the leaves and can force it into summer dormancy. A cool-climate woodlander. per NC State
Early food for native bees
Its spring flowers feed emerging native bees and bumblebees early in the season, when little else is blooming; butterflies visit too. per NC State and Wildflower Center
Deer resistant
Deer usually leave it alone; three sources rate it deer resistant, though very hungry deer may still nibble. per NC State
Grown for their foliage
Some varieties are grown for their leaves, not flowers: 'Stairway to Heaven' has cream-and-green variegated foliage; 'Heaven Scent' emerges reddish. per Chicago Botanic Garden
What pairs well with Jacob's Ladder
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Hellebore
Shares part shade and moderate water; blooms in late winter, before this one opens; both offer pollinator forage, in different months; evergreen, so the bed keeps its shape through winter.
Summersweet
Shares part shade and moderate to high water; blooms in midsummer as this one finishes; both are strong pollinator plants, and they feed in different months; taller at 5.9 ft, for the layer behind it.
Cardinal Flower
Takes part sun to part shade and moderate to high water; blooms in midsummer as this one finishes; both are strong pollinator plants, and they feed in different months; taller at 3.3 ft, for the layer behind it.
Northern Sea Oats
Shares part shade and moderate water; blooms in midsummer as this one finishes; its seed heads stand through winter, for structure and the birds; taller at 3.3 ft, for the layer behind it.
Eastern Redbud
Takes part sun to part shade and moderate water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months; both are native plants.
Serviceberry
Takes part sun to part shade and moderate water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months; both are native plants.
Monkshood
Takes part sun to part shade and moderate water; blooms in late summer, extending the bed's season; both offer pollinator forage, in different months; taller at 3.9 ft, for the layer behind it.
Witch Hazel
Takes part sun to part shade and moderate water; blooms in late winter, before this one opens; both offer pollinator forage, in different months; taller at 9.8 ft, for the layer behind it.
Featured in these guides
Explore similar plants
You might also like
Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.