Origin
Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn, commonly known as bush lupine, is a native West Coast plant found in British Columbia, Canada, south to Baja California, Mexico.
Common Names
Bush lupine is also commonly known as coastal bush lupine, tall lupine, and western lupine.
Uses
Bush lupine is used for erosion control, reclamation, and landscaping due to its deep root system and tolerance for dry, sandy, and nutrient-poor soils. Additionally, bush lupine contains alkaloids that were used as food by various Native American tribes, although these alkaloids can be toxic if consumed in large amounts. Bush lupine is also an important host plant for the larvae of the endangered mission blue butterfly.
General Appearance
Bush lupine is a perennial shrub that can grow up to six feet tall and four feet wide. The plant has dark green palmate leaves that grow up to ten inches long. The leaves are divided into 9-17 leaflets, with each leaflet being 1-3 inches long and ½-1 inch wide. The showy flowers bloom in spikes of pea-like flowers that are typically blue-purple, although they can also be white or pink. The fruit is a hairy pod that is 1-2 inches long.
Growth Conditions for Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn
Light: Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn generally thrives in areas with full sun exposure or partial shade. It requires a minimum of six hours of direct sunlight per day for optimal growth.
Temperature: This subspecies of Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn prefers a temperate climate, with moderate temperatures ranging from 50 to 80 degrees Fahrenheit. It cannot withstand extreme hot or cold temperatures, making it intolerable in regions with harsh weather conditions.
Soil: Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn thrives in well-drained, sandy, or slightly acidic soil with a pH range of 6.5 to 7.5. It cannot tolerate waterlogged or heavy clay soils, which can cause root rot and hinder growth. Ideally, it would grow in areas with loose soils that promote good airflow, leading to an excellent root system.
Cultivation Methods
Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn, commonly known as the bush lupine, is a low-growing woody shrub that requires full sun and well-drained soil. It can tolerate sandy soils and is commonly found near coastal bluffs and dunes.
The plant can be propagated through seeds, and it is recommended to sow them in the fall to allow for the natural stratification process. The seeds should be sown directly into the soil with a depth of half an inch and spaced about 1 foot apart.
The shrub also spreads through underground root suckers, so be sure to provide enough space for the bush lupine to expand.
Watering Needs
Bush lupines are drought-tolerant plants, but they will benefit from regular watering during the growing season. It is best to water them deeply and slowly, allowing the soil to absorb the water without running off.
During the summer months, when the plant is in full bloom, it is recommended to water it once a week, or more frequently if the weather is particularly hot and dry. In the winter months, the plant can go without water for longer periods, but be sure not to let the soil dry out completely.
Fertilization
Bush lupines do not require much fertilization, as they are adapted to growing in nutrient-poor soils. However, if you want to promote more vigorous growth and blooming, you can apply a balanced fertilizer in the early spring before new growth appears.
Avoid applying too much nitrogen fertilizer, which can lead to excessive vegetative growth at the expense of flowering.
Pruning
Bush lupines require minimal pruning since they naturally grow in a low and bushy form. However, you can remove any dead or damaged branches in the late winter or early spring before new growth appears.
You can also prune the plant to shape it or maintain a particular size. If you want the shrub to remain low and bushy, avoid pruning the central stem. Instead, selectively prune the side branches to promote a more dense growth habit.
Propagation of Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn
Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn, commonly known as bush lupine, is a beautiful flowering plant that is native to the coastal regions of Oregon. This plant has a woody stem and can grow up to 6 feet tall. The leaves of bush lupine are compound and palmate, with 7-10 leaflets. The flowers of this plant are blue or purple and bloom from April to July.
Propagation Methods
Bush lupine can be propagated by seeds, cuttings, or division.
Propagation by Seeds
The seeds of bush lupine should be sown in the fall, as they require a period of cold stratification to germinate. The seeds should be sown in well-draining soil and should be covered with a light layer of soil. The soil should be kept moist, but not saturated. The seeds typically germinate in the spring, after a cold winter.
Propagation by Cuttings
Bush lupine can also be propagated by stem cuttings. The best time to take cuttings is in the summer, when the plant is actively growing. The cuttings should be taken from the tips of the stems, and should be about 3-4 inches long. The leaves on the lower half of the cutting should be removed, and the cutting should be dipped in rooting hormone. The cutting should be planted in well-draining soil and should be kept moist. The cutting will typically root in about 4-6 weeks.
Propagation by Division
Bush lupine can also be propagated by division. The best time to divide the plant is in the fall, after the plant has finished flowering. The plant should be dug up and the root ball should be divided into smaller sections. Each section should have some roots and some stems. The divided plants can be replanted in well-draining soil and should be kept moist while they establish their root systems.
Overall, bush lupine is a beautiful plant that can be easily propagated by seeds, cuttings, or division. With a little bit of effort, you can propagate this plant and enjoy it in your garden for years to come.
Disease and Pest Management for Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn
Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn is a perennial plant that is native to North America and is commonly known as silvery lupine. This plant is often used for landscaping as it produces attractive and colorful flowers. Managing diseases and pests is essential for healthy growth of these plants. Here are some of the common diseases and pests that may affect Lupinus arbustus Dougl. ex Lindl. ssp. silvicola (Heller) D. Dunn, along with ways to manage them.
Common Diseases
1. Root Rot: Root rot is caused by a fungus that attacks the roots of the plant, leading to yellowing of the foliage, wilting, and death. To prevent root rot, it is recommended to plant the lupines in well-draining soil, avoid overwatering, and remove any infected plants from the area. In case of severe infection, it is advisable to use a fungicide.
2. Powdery Mildew: Powdery mildew is a fungal disease that affects the foliage of the plant, causing a white or gray powdery coating on the leaves. This disease can be prevented by ensuring proper air circulation around the plant, avoiding overhead watering, and removing any infected foliage. In case of severe infection, fungicides can be used.
3. Bacterial Blight: Bacterial blight causes water-soaked lesions on the leaves of the plant, which turn brown and dry out. The disease can be controlled by avoiding overhead watering, removing infected plant parts, and using copper-based fungicides.
Common Pests
1. Aphids: Aphids are small green insects that suck the sap from the plant, causing stunted growth and distorted foliage. Aphids can be controlled by using insecticidal soaps or neem oil, or by introducing natural predators such as ladybugs or lacewings.
2. Cutworms: Cutworms are the larvae of certain species of moths that feed on the stem of the plant at soil level, cutting off the entire plant. To prevent cutworms, it is recommended to use collars made of cardboard or plastic around the base of the plant, or to use insecticides.
3. Spider Mites: Spider mites are tiny pests that feed on the underside of the foliage, causing a yellow stippling pattern on the leaves. They can be controlled by spraying the plant with water to remove them, or by using miticides.
