Overview: Polemonium occidentale Greene var. lacustre (Wherry) Lakela
Polemonium occidentale Greene var. lacustre (Wherry) Lakela, commonly known as the western polemonium or Jacob's ladder, is a herbaceous perennial plant that belongs to the family Polemoniaceae. This plant is native to the western regions of North America, including the western United States and Canada. It grows in moist areas, such as the edges of streams, lake shores, and wet meadows, and can be found in elevation ranging from sea level to around 3300 meters.
Common Names
The western polemonium has several common names, including western polemonium, Jacob's ladder, and riverbank polemonium. These names are used differently depending on the location, but they all refer to the same plant.
Appearance
The western polemonium has a unique appearance. It has a basal rosette of compound leaves that form a clump of up to 60 cm wide and 35 cm tall. The leaves are pinnate, with oval leaflets that are finely toothed at the edges and hairy underneath. The stems are erect, reaching up to 75 cm tall, and bear several small, blue-violet flowers arranged in clusters. The flowers have five fused petals, five stamens, and a single pistil. They bloom from May to August.
Uses
The western polemonium has several uses. It is a popular ornamental plant because of its attractive appearance and ability to grow in moist areas. It is also used in traditional medicine by some Native American tribes to treat various ailments such as fever, cough, and diarrhea. However, it is important to note that this plant may be toxic if ingested in large quantities, and it should only be used under the guidance of a medical professional.
Light Requirements
Polemonium occidentale var. lacustre typically grow in sunny to partially shaded areas. In the wild, it can be found growing in bogs, fens, wet meadows, and other wetland habitats. However, it can also tolerate some dry conditions, making it a versatile plant for many different growing conditions.
Temperature Requirements
These plants can grow in a wide range of temperatures, but generally prefer cooler climates. They are native to the western United States and can be found growing in mountainous regions up to 10,000 feet in elevation. In cultivation, they are considered hardy in USDA zones 3 to 8, meaning they can tolerate winter temperatures as low as -40°F.
Soil Requirements
Polemonium occidentale var. lacustre grows best in well-draining, moist soils. They are often found growing in wetlands, so they prefer soils that are consistently moist but not waterlogged. The pH of the soil should be slightly acidic to neutral (pH 6.0 to 7.0). Good soil texture is also important, as these plants require oxygen to reach their roots. Sandy loam soils are optimal for growing this plant, but it can also tolerate heavier clay soils.
Cultivation
Polemonium occidentale Greene var. lacustre (Wherry) Lakela prefers to grow in moist, well-drained soil that is rich in organic matter. The plant thrives in partially shaded areas, and grows well in gardens and meadows. It does not require much maintenance and can tolerate some drought, although it prefers to be watered regularly.
Watering Needs
Regular watering is necessary for Polemonium occidentale Greene var. lacustre (Wherry) Lakela, especially during the hot and dry seasons. The plant prefers moist soil, so water it frequently to keep the soil moist but not waterlogged. Mulching around the plant can help retain moisture in the soil.
Fertilization
Polemonium occidentale Greene var. lacustre (Wherry) Lakela does not require too much fertilization, as it prefers soil rich in organic matter. However, a light application of balanced fertilizer, such as a 10-10-10 blend, can be applied once a month during the growing season to promote growth and flowering.
Pruning
Polemonium occidentale Greene var. lacustre (Wherry) Lakela does not require much pruning, as it has a naturally compact growth habit. However, it is a good idea to remove any dead or damaged stems to promote new growth. Pruning can be done after flowering or in the early spring.
Propagation of Polemonium occidentale Greene var. lacustre (Wherry) Lakela
Polemonium occidentale Greene var. lacustre (Wherry) Lakela, commonly known as Western Jacobs ladder, is a beautiful perennial plant that can be propagated by seeds, cuttings, and division.
Propagation by seeds
The easiest and simplest way to propagate Polemonium occidentale Greene var. lacustre is by using seeds. The plant produces seed pods that ripen in the late summer or early fall. The seeds can be collected by hand and sown immediately or stored in a cool and dry place for later use. The seeds should be planted in well-draining soil in a sunny or partially shaded spot and kept moist until they germinate.
Propagation by cuttings
Polemonium occidentale Greene var. lacustre can also be propagated by stem cuttings. Select a healthy stem that does not have any flowers or buds and make a clean cut just below a node. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cutting in a well-draining soil mix, keep it moist, and place it in a shaded location until roots have developed. Once the roots are established, the cutting can be planted in its permanent location.
Propagation by division
Polemonium occidentale Greene var. lacustre can also be propagated by division. Wait for the plant to mature and develop a clump of stems. Dig up the clump carefully with a fork and separate the stems into smaller clumps. Replant the smaller clumps in a well-draining soil mix and keep them moist until they establish roots in their new location.
Disease management
Polemonium occidentale Greene var. lacustre (Wherry) Lakela can be affected by different types of diseases. Here are some of the most common ones:
Leaf spot
Leaf spot is a fungal disease that causes circular or irregular spots on the leaves of the plant. To control this disease, it is important to remove and destroy infected leaves. Fungicides can also be used to keep the disease from spreading.
Root rot
Root rot is a fungal disease that affects the roots of the plant, leading to a decay of the tissue. To prevent this disease, it is important to ensure that the soil is well-drained and not too wet. Fungicides can also be used to control the disease.
Powdery mildew
Powdery mildew is a fungal disease that appears as a white, powdery substance on the leaves of the plant. To control this disease, it is important to remove infected leaves and improve air circulation around the plant. Fungicides can also be used to control the spread of the disease.
Pest management
Pests can also be a problem for Polemonium occidentale Greene var. lacustre (Wherry) Lakela. Here are some of the most common pests and ways to control them:
Aphids
Aphids are small insects that feed on the sap of the plant, causing stunted growth and distortion of the leaves. To control aphids, insecticidal soap can be used or the plant can be sprayed with a strong stream of water to remove the insects.
Spider mites
Spider mites are tiny insects that feed on the plant's foliage, causing yellowing and bronzing of the leaves. To control spider mites, the plant can be sprayed with insecticidal soap or neem oil, or a miticide can be used.
Slugs
Slugs are mollusks that feed on the leaves of the plant, leaving large holes. To control slugs, it is important to remove hiding places such as rocks and old leaves around the plant, and to use baits such as beer traps or iron phosphate.
