Polemonium

( pol - em - MOH - nee - um )

At-A-Glance Information

This genus of flowering perennials (rarely annuals) is commonly called Jacob's Ladders, and needs partial to full shade and regular water. They have ferny foliage and clusters of bell-shaped blue (rarely white or pink) flowers in spring and summertime. These are great candidates for under-tree plantings, as their root systems are not invasive. Most species are native to cool temperate to arctic regions in the Northern Hemisphere and reach between 4 and 47 inches tall when in bloom. 

Polemonium Species and Varietals

Polemonium is the type genus member of the plant family Polemoniaceae and includes between 25 and 40 distinct species. Polemonium grows best in zones 1-11 and 14-17, though this varies somewhat depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Polemonium caeruleum (Jacob's Ladder)
This species is native to Europe and Asia, and has a somewhat upright habit, reaching 1-3 feet tall and 1-1.5 feet wide. Flowers are lavender-blue. Variety 'Brise d'Anjou' (pictured) has leaves outlined in white. Other commonly grown garden cultivars include 'Album' (with white flowers), 'Blue Pearl', 'White Pearl' (with white flowers) and 'Snow and Sapphires' (with variegated foliage).

Polemonium californicum (Moving Polemonium, Low Jacob's-Ladder, California Jacob's Ladder)
Native to the northwestern United States, these plants prefer shady, moist habitats like mountain woodland areas. Individual plants form clumps of 12-20 inches. 

Polemonium carneum (Royal Jacob's Ladder, Great Polemonium, Oregon Polemonium, Salmon Polemonium)
This species is native to Washington and California, and reaches 1-1.5 feet tall and about as wide. Flower buds are yellow, and open to reveal peach-pink blossoms that mature to a purplish-blue color.

Polemonium eximium (Skypilot, Showy Sky Pilot)
This perennial species grows at high altitudes, and is endemic to the Sierra Nevada mountain range in California. This is a very sought-after wildflower and produces a 4-16 inch tall plant with sticky, aromatic foliage. Fragrant flowers are dark blue, sometimes whitish-blue or pink-lavender. They are somewhat unpleasant smelling, their urine-like fragrance attracts their best pollinators.

​Polemonium 'Firmament'
This is a hybrid between Polemonium caeruleum and Polemonium reptans, which reaches 20 inches tall and a foot wide with bright  blue flowers. It is wonderful in borders.

Polemonium pulcherrimum (Beautiful Jacob's Ladder, Showy Jacob's Ladder, Skunk-Leaved Polemonium)
This species grows well in zones A1-A3, 1-11, 14-17 and H1 and is native from Alaska down to California. It can be either sprawling or erect, growing to a foot tall and just as wide. Flowers bloom in clusters of blue or white, and often have yellow throats. Great for shady, rocky areas of the garden. Foliage smells like a skunk.

Polemonium reptans (Spreading Jacob's Ladder, Creeping Jacob's Ladder, False Jacob's Ladder, Abscess Root, American Greek Valerian, Blue Bells, Stairway to Heaven, Sweatroot)
This species is native to eastern areas of the United States and grows to 1-1.5 feet tall and a foot wide. Flowers are light blue. This plant is best known through its variety 'Blue Pearl', a plant that reaches just 10 inches tall and 1.5 feet wide, with bright blue flowers. This species and its varietals are wonderful in shaded rock gardens.

Polemonium vanbruntiae (Appalachian Jacob's Ladder, Bog Jacob's Ladder, Vanbrunt's Polemonium)
These perennial plants have green foliage and produce purple flowers from the middle of June to late July. They prefer to grow in wetland-type landscapes such as bogs, swamps, and marshes.

Caring for Polemonium

Propagation

Problems and Pests

Gallery

Camellias are great candidates to be grown as container plants on your patio.
A field of thea sinensis
Camellia hiemalis 'Shishi Gashira'

Videos

A video all about growing camellias successfully
Propagating camellias

Resources

Wikipedia: Polemonium
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Page 522, Polemonium
If you have any questions, comments, concerns, or photos you’d like to add to the gallery, please let me know by sending me a message using the button below!
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