Although Jacob's Ladder plants are relatively pest free and low maintenance, they are particular about where they will grow. But if you have the right conditions, as described below, Jacob's Ladder is lovely.
Flowers: Most Jacob's Ladder plants have bell-shaped flowers in shades of purple and lavender, but there are also white, pink and yellow varieties available, although harder to find.
Leaves: The compound leaves are composed of rows of narrow, pinnate leaflets. The branches grow from a basal rosette and arch and sway as they grow tall.
Common Name(s):Jacob's Ladder
USDA Hardiness Zones:
- Polemonium 'Album' - White Flowering
- Polemonium - 'Bambino Blue'
- Polemonium 'Snow and Sapphires' - Variegated leaves and blue flowers. Somewhat hardier than the similar 'Brise d'Anjou' (24--30" tall. Zones 5-8)
- Polemonium'Stairway to Heaven' - Blue flowers on variegated foliage that blushes pink, in cool weather. (12--24" tall. Zones 4 - 8)
Starting Jacob's Ladder Seed: If you already have a Jacob's Ladder plant, it will self-seed on its own. You could also collect seed to replant elsewhere. Jacob's Ladder can be direct seeded in either spring or fall. Loosely cover the seed with soil, water and keep moist and be sure to mark the spot so that you do not disturb it.
To start seed indoors, sow either 2 months before your last frost date or in mid-summer, to transplant in the fall. Seed takes up to a month to germinate and should be keep moist until then. Transplant outdoors in spring, just before your last frost date, or in early to mid-fall.
Dividing Jacob's Ladder Plants: Jacob's Ladder plants should be divided every 2 - 4 years, or they will start to die out in the center. They divide most easily and successfully in early spring. Carefully lift and separate the basal rosettes, replant and water well.
Soil: Jacob's Ladder is more fussy about moisture than about soil pH, but they will grow best in a loose, rich soil with a neutral soil pH of about 6.2 - 7.0.
Exposure: Jacob's Ladder plants prefer partial or dappled shade and a moist, but well-draining soil. Plants that receive regular watering will bloom longer and remain attractive into summer.
Maintenance: Jacob's Ladder requires minimal maintenance. Once the flowers finish blooming, cut the flower stalks back to the plant's base. You should get repeat blooms.
If the foliage starts to look tattered, it too can be cut back and cleaned up. New growth will replace the trimmed foliage.
Feeding: Jacob's Ladder is a long-lived perennial. Give the plants a boost in early spring with a dose of balanced fertilizer, as the new growth is emerging. I like to feed them again, once the faded flowers have been cut back.
Pests & Diseases:Jacob's Ladder plants are generally problem free, but there are a few pests and diseases that will attack, particularly is the plants are stressed. The most common problems are sun scorch and insufficient water, which cause the leaf tips to start browning. Other potential problems include:
They are also apparently delicious to grounghogs.