Jacob’s Ladder Plant Care: How to Grow Jacob’s Ladder

Jacob’s ladder is a woodland herbaceous perennial in the Polemoniaceae (phlox) family. Its pinnate dark green leaves climb along its stems in pairs, like a ladder. During its bloom time (April or May), Jacob’s ladder erupts in clusters of lavender-blue wildflowers that hang down from the stems. Jacob’s ladder thrives in USDA Hardiness Zones four through nine. If sheltered from excessive heat, humidity, and sunlight, Jacob’s ladder is relatively low-maintenance.

Two related species—Polemonium reptans and Polemonium caeruleum—share the name Jacob’s ladder. Polemonium reptans grows as a native plant in the US northeast and is a threatened species in some areas; it’s therefore not sold as a gardening plant. Polemonium caeruleum, also known by the common name Greek valerian, has several cultivars recognizable by flower color. These include:

1. 1. Album: The Album cultivar has white flowers instead of lavender or blue.
2. 2. Bambino Blue: Bambino Blue’s flowers tend to be significantly lighter in color.
3. 3. Snow and Sapphires: This variety does have lavender or blue flowers (“sapphires”) but also has white-striped variegated leaves (“snow”).
4. 4. Stairway to Heaven: Like Snow and Sapphires, Stairway to Heaven has variegated leaves, but Stairway’s leaves turn pink in cooler weather.

You can propagate Jacob’s ladder from seed or by division. Sow seeds in late spring or early summer, well after the last frost. Bury them about eighteen inches apart in rich, moist soil in a part of the garden that gets partial shade. Make sure they get plenty of water until they sprout.

To divide an existing Jacob’s ladder plant, first dig up the plant, then gently separate the roots to produce several new plants. Replant the new plants at least eighteen inches apart and water well until established.

Jacob’s ladder doesn’t require a lot of attention to get along in your garden. Since it’s a woodland plant, it requires at least partial shade; placing the plant in full sun will cause the leaves to scorch and wither. Jacob’s ladder prefers a slightly acidic soil pH. Keep the soil moist, not soggy, by periodically mulching your Jacob’s ladder with leaves.

Jacob’s ladder tends to be quite hardy and shouldn’t give you much trouble.

1. 1. Diseases and pests: Jacob’s ladder is deer-resistant and isn’t often a target for pests, though if its leaves don’t receive enough airflow or get too moist, it can develop powdery mildew or leaf spot. You should also keep an eye out for slugs.
2. 2. Regular Maintenance: Depending on how much new growth your Jacob’s ladder exhibits, you should plan on dividing and replanting about every two to four years.
3. 3. Trimming: You may need to cut back your Jacob’s ladder if the stems start to get too leggy. Learn how to prune plants in your garden.

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