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Description
Polemonium, commonly known as Jacob’s ladder, is a genus of flowering plants in the family Polemoniaceae. It is native to North America and Europe and consists of about 25 species of herbaceous perennials. The name “Jacob’s ladder” comes from the arrangement of its leaves, which resemble the rungs of a ladder. The plant is widely grown in gardens and is popular for its attractive foliage and delicate flowers.
Taxonomic Information
| Domain | Eukaryota |
|---|---|
| Kingdom | Plantae |
| Phylum | Spermatophyta |
| Class | Magnoliopsida |
| Order | Ericales |
| Family | Polemoniaceae |
| Genus | Polemonium |
Appearance
Polemonium plants can grow up to 60 cm tall and have a spread of 30 to 60 cm. The leaves are pinnate, with each leaflet being ovate or lanceolate in shape. The flowers are usually blue or purple, but can also be pink or white, and are arranged in loose clusters. They have five petals and five stamens and bloom in late spring to early summer. Some varieties also produce small, round, black seeds.
Care Guide
Polemonium plants prefer moist, well-draining soil and partial shade to full sun. They require regular watering, especially during the growing season, but should be allowed to dry out slightly between waterings. Fertilization should be done once a month during the growing season using a balanced fertilizer. These plants are hardy and can grow in hardiness zones 3 to 8.
Common Pests & Diseases
Polemonium plants are generally resistant to pests and diseases. However, they can be susceptible to powdery mildew, a fungal disease that causes a white, powdery coating on the leaves. This can be treated by removing affected leaves and spraying the plant with a fungicide. Aphids and spider mites can also occasionally infest the plant, which can be controlled with insecticidal soap or neem oil.
Habitat
Polemonium plants are native to North America and Europe, where they grow in meadows, forests, and along stream banks. They are also commonly grown in gardens and landscaping.
Question and Answer
Q: Can Polemonium plants grow in full sun?
A: Yes, Polemonium plants can grow in full sun, but they prefer partial shade.
Q: When is the best time to fertilize Polemonium plants?
A: Fertilization should be done once a month during the growing season.
Q: How do I control powdery mildew on my Polemonium plant?
A: Remove affected leaves and spray the plant with a fungicide.
Q: What hardiness zones can Polemonium plants grow in?
A: Polemonium plants can grow in hardiness zones 3 to 8.
Related Plants
- Polemonium caeruleum
- Polemonium reptans
- Polemonium boreale
- Polemonium viscosum
References
- Encyclopedia Britannica. (n.d.). Polemonium. In Britannica Online. Retrieved August 3, 2021, from https://www.britannica.com/plant/Polemonium.
- Missouri Botanical Garden. (n.d.). Polemonium. In Missouri Botanical Garden. Retrieved August 3, 2021, from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=b429.
- University of Florida IFAS Extension. (2021). Jacob’s Ladder. In Gardening Solutions. Retrieved August 3, 2021, from https://gardeningsolutions.ifas.ufl.edu/plants/ornamentals/jacobs-ladder.html.
