Showy Jacob's Ladder Plant Care
Polemonium foliosissimum A.Gray
Updated · Sources · How we source care data
Polemonium foliosissimum, the towering Jacob's-ladder, is a rare species of flowering plant in the phlox family Polemoniaceae, native to the western United States; Arizona, Colorado, Idaho, Nevada, New Mexico, Utah and Wyoming. As its synonym Polemonium archibaldiae it has gained the Royal Horticultural Society's Award of Garden Merit.
Every 7–10 days
Partial shade to full shade
50–75°F
40–70%
At a glance
How do you care for Showy Jacob's Ladder?
Water Showy Jacob's Ladder every 7–10 days, letting the top layer of soil dry out between waterings, and give it partial shade to full shade. It prefers temperatures of 50–75°F (10–24°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Showy Jacob's Ladder Native To?
What Is the Showy Jacob's Ladder?
Showy Jacob's Ladder (Polemonium foliosissimum) belongs to the Polemoniaceae family within the Polemonium genus. Showy Jacob's Ladder is native to the western United States. Showy Jacob's Ladder is also known as Manyleaf Jacob's Ladder.
Showy Jacob's Ladder displays a clumping perennial growth habit, reaching up to 1.5 ft tall with a spread of approximately 1 ft. Showy Jacob's Ladder produces clusters of tubular, bell-shaped flowers in shades of blue, pink, or white.
Leaf size: approximately 4 inches.
How Often Should You Water a Showy Jacob's Ladder?
Polemonium foliosissimum requires watering every 7–10 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–10 days
Let soil partially dry between waterings
What Light Does the Showy Jacob's Ladder Need?
Showy Jacob's Ladder thrives in partial shade to full shade. The optimal light range is 100–1,000 lux. Avoid placing Showy Jacob's Ladder in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Partial shade to full shade
100–1,000 lux
What Temperature and Humidity Does the Showy Jacob's Ladder Prefer?
Polemonium foliosissimum grows best at temperatures of 50–75°F. Showy Jacob's Ladder prefers humidity levels of 40–70%.
Temperature
50–75°F
Humidity
40–70%
What Soil Mix Works Best for a Showy Jacob's Ladder?
Moist, well-draining soil with high organic content. Good drainage is essential for Showy Jacob's Ladder to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Showy Jacob's Ladder?
Feed Showy Jacob's Ladder every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Showy Jacob's Ladder?
Divide clumps every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Showy Jacob's Ladder?
Showy Jacob's Ladder can be propagated through seeds, division. Similar propagation techniques also apply to sharp-flowered jacob's ladder plant care, which shares the same genus.
Is the Showy Jacob's Ladder Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Showy Jacob's Ladder, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Showy Jacob's Ladder?
Showy Jacob's Ladder is susceptible to aphids, spider mites, powdery mildew. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Showy Jacob's Ladder Need?
Showy Jacob's Ladder grows outdoors in USDA Zone 12a. It survives winters down to planting zone 12a. Showy Jacob's Ladder is native to the western United States. In cooler regions, grow Showy Jacob's Ladder as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Showy Jacob's Ladder is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Polemonium genus — compare its care with other Polemonium species on PlantoScan.
Polemonium is part of the Polemoniaceae plant family — browse all Polemoniaceae genera and species.
Showy Jacob's Ladder copes with lower light than most plants — browse the full list of low-light plants.
More Polemonium Species
Other Polemonium species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Polemonium foliosissimum A.Gray, family Polemoniaceae (first published in Syn. Fl. N. Amer. 2(1): 151 (1878)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Showy Jacob's Ladder, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Hardiness zone: USDA Zone 12a, calculated from the plant's minimum temperature.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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