Polemonium Plant Profile
Garden Care, Uses, Growing and Varieties of Jacob's Ladder
Shade loving, bright flowering and extremely winter hardy, Jacob's ladder is an excellent choice for a wide variety of gardens and landscapes.
Botanical and Common Name: Polemonium has a couple of common names including Jacob's Ladder and Greek Valerian.
Plant Category: Jacob's Ladder is perennial to Zone 3 or 4.
Bloom Time and Color: Polemonium plants flower each spring and early summer with charming blue, lavender or pink flowers. With summer cutting back an autumn flush of flowers is often seen.
Foliage: The foliage of the Jacob's Ladder gives the plant its charming common name because the leaves are opposite and resemble a primitive step ladder.
Growth Habit: Polemonium has a lovely growth habit that is slightly upright with charming foliage shape.
Dimensions: Most polemonium will grow 2-4' tall but some smaller forms do exist.
Preferred Conditions: Jacob's ladder prefers slightly moist soil but will tolerate a fairly wide range of soil fertility. Part shade is preferred but full sun is appreciated in cooler climates. Full shade is tolerated in dappled or bright shade conditions and beneficial to polemonium plants in hot, humid summers. If Jacob's ladder foliage fades in the summer it is getting too hot.
Maintenance: If the leaves of the polemonium fade in the heat of summer the gardener should cut the stems down and water deeply to allow a fall flush of foliage, otherwise Jacob's ladder needs little maintenance.
Pests or Diseases: Mildew can be a problem for polemonium in humid areas and sun scorch can brown the leaves if your Jacob's ladder gets too much sun but otherwise these perennials have few pest or disease problems.
Propagation Methods: Easily divided, polemonium species can also be grown from seed. Specific cultivars should be purchased as started plants or acquired through division since they may not come true from seed.
Companion Plants: Combine Jacob's ladder with other spring blooming plants like Primrose, Snapdragons or impatiens for a beautiful spring border. To provide year-round interest combine polemonium with other interesting foliage plants like evergreen shrubs, winter flowers, and fall plants. Use polemonium with other shade plants for beds under large, shade trees combining with hostas, ferns, hellebores and bell flowers.
Seasons of Interest: Polemonium is interesting spring through frost as the foliage is highly attractive even once the flowers fade in summer.
Uses in the Garden: Mixed borders, shady under-plantings, foliage gardens, blue or pink flowering gardens, and cottage gardens are all appropriate uses for Jacob's ladder.
Varieties and Cultivars:
Polemonium caeruleum: This species gives the most popular Jacob's ladders for home garden landscaping.
- P. caeruleum album – A charming white flowering form that grows to 3' tall.
- 'Brise d'Anjou' – A variegated form of Jacob's ladder that increases the foliage interest.
- 'Snow and Sapphires' – Another variegated form the “Snow” of its name refers to the white striped foliage and the “Sapphires” part of the name refers to the stunning blue flowers.
- 'Bressingham Purple' – This dwarf polemonium has purple-tinted foliage and bright blue flowers.
Polemonium carneum – The flowers of this polemonium species are more shallow, saucer-shaped rather than funnel-shaped like the other Jacob's ladders and tend to be much shorter for front of the border use.
- 'Apricot Delight' – At only 16” tall this Jacob's ladder is still a show-stopper with apricot colored flowers.
Polemonium reptans – A lower-growing, more sprawling species of Jacob's ladder, P. reptans specimens usually have very beautiful flower forms. Sometimes called “Creeping Jacob's Ladder” because of its rhizomatic root system this species is native to Missouri according to the Missouri Botanical Garden website.
- 'Blue Pearl' – Blue flowers slightly darker in shade than the P. reptans species.
- 'Pink Dawn' – A 12” tall pink flowering form that contrasts nicely with other Jacob's ladder plants.
