Origin
Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby, commonly known as Spotted silver lupine, is a perennial plant species that is native to North America. It is found in many states of the United States such as Arizona, Colorado, Idaho, Nevada, New Mexico, Utah, and Wyoming. This plant is adapted to grow in dry sandy or rocky soil at elevations ranging from 4,000 to 11,000 feet.
Common Names
The Spotted silver lupine is recognized by many common names, including Silver lupine, Spotted lupine, Spotted silver-leaf lupine, and Fulvous-spotted lupine. These names describe the unique appearance of the plant and its blooms.
Uses
Spotted silver lupine is cultivated as an ornamental plant and used in native plant landscaping. The plant is an important species for reclamation and restoration projects because it enhances soil fertility with its root nodules which contain nitrogen-fixing bacteria. It also provides food for native wildlife, such as elk, deer, and other herbivores. The plant's seeds are also used for food by humans and were an essential part of the diet of Native Americans who ground them into flour and made them into cakes.
General Appearance
The Spotted silver lupine has a herbaceous growth habit and typically grows to about 1-3 feet tall and 2-3 feet wide. The leaves of the plant are gray-green in color, silvery-hairy, palmately compound with up to eight narrow leaflets. The plant's blooms appear in late spring or early summer, producing a spike-like raceme that can grow up to 10 inches long. The flower color can range from deep blue-violet to lavender to white, with yellow and maroon markings that appear in spots on the petals. The plant's fruit is a hairy, flattened legume pod that contains 1 to 4 seeds.
Light Requirements
Lupinus argenteus Pursh var. fulvomaculatus require full sun to partial shade for optimum growth. It means they need a minimum of 6 hours of full sunlight per day to thrive. Partial shade means some protection from direct afternoon sun, particularly in hot climates. They grow best in areas that receive more sun than shade and will tolerate direct sunlight in cooler climates.
Temperature Requirements
Lupinus argenteus Pursh var. fulvomaculatus are native to the Western United States and Canada. They thrive in areas with a continental climate with hot summers and cold winters. They can tolerate summer temperatures up to 85°F (29.4°C) and winter temperatures as low as -20°F (-28.9°C). Lupinus argenteus Pursh var. fulvomaculatus are hardy plants and can tolerate a wide range of temperatures and climatic conditions.
Soil Requirements
Lupinus argenteus Pursh var. fulvomaculatus prefer well-draining soil that is rich in organic matter. They grow well in rocky or sandy soil with a pH range of 6.5 to 7.5. They are tolerant of poor or nutrient-deficient soils, but the soil must be well-draining to avoid waterlogging. The recommended soil texture for the plant is sandy loam. If the soil is clay, amending with compost, sand, or grit to improve drainage will be necessary.
Cultivation Methods
Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby is best grown in areas with cool summer climates where there is good drainage. These plants prefer to be in full sun, although they can tolerate some shade. In terms of soil, they grow well in soils that are well-drained and have a slightly acidic pH level, ranging from 5.5 to 6.5. Sandy soils are preferable to clay soils.
Watering Needs
These plants require regular watering during their growing season, which is in the spring and summer. Watering should be done evenly to avoid waterlogging the soil. It is best to water them early in the morning so that the leaves can dry out before the sun gets too hot. Irrigation systems can be set up to fulfill watering needs.
Fertilization
To keep Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby healthy and to help it thrive, fertilization is necessary. A good option is to use a balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium. The fertilizer should be applied in early spring when the plant begins growing. A slow-release fertilizer will provide continuous feeding through the growing season and will require reapplication less frequently.
Pruning
Pruning is not necessary for Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby, but if you feel it’s necessary to control the height or shape, then it is best to do it in the late fall or early spring. Make sure to sterilize your pruning tools before and after use with a solution of 1 part water to 9 parts bleach to avoid the spread of disease. Remove any dead or wilted plant material from the plant to help promote healthy growth.
Propagation of Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby
Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby, commonly known as spotted silver lupine, is a perennial herbaceous plant that is native to western North America. This plant is propagated using various methods which include:
Seed Propagation
The most common propagation method for Lupinus argenteus is through seeds. Seeds can be sown directly into the ground during the fall or stratified and sown in the spring. Stratification involves placing the seed in moist soil and refrigerating it for several weeks. Once stratified, the seeds can be sown in containers or directly in the ground.
Vegetative Propagation
Lupinus argenteus can be propagated vegetatively using stem cuttings or root cuttings. Stem cuttings are taken from the parent plant and rooted in moist soil. Root cuttings are taken from the parent plant's root system and similarly rooted in moist soil.
Division
Division is another method of propagation that can be used to produce new Lupinus argenteus plants. Divide the parent plant during the fall by separating the plant into sections with a sharp saw or knife, ensuring that each section has roots.
These propagation methods can be used to produce new Lupinus argenteus plants, each with unique characteristics. Ensure that the plants are grown in well-draining soils, exposed to sunlight and capable of withstanding periods of drought.
Disease Management
Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby is generally resistant to many diseases that affect other plants. However, it can still be affected by some fungal diseases, including:
- Anthracnose: This disease typically affects the leaves and stems of the plant, causing dark, sunken lesions that may develop yellow halos. Infected leaves may also appear brown and wilted. To manage this disease, affected plant parts should be removed and destroyed. Fungicides may also be applied to protect the plant.
- Rust: Rust appears as small orange or yellow pustules on the undersides of leaves. Infected leaves may also turn yellow and drop prematurely. To manage rust, remove and destroy infected leaves, and use a fungicide to prevent the spread of the disease.
To prevent the occurrence of fungal diseases, ensure that there is adequate air circulation around the plant and avoid overhead watering.
Pest Management
Lupinus argenteus Pursh var. fulvomaculatus (Payson) Barneby can also be affected by some pests, including:
- Aphids: Aphids are small, pear-shaped insects that feed on the sap of the plant, causing wilted and distorted growth. To manage aphids, spray the plant with a strong stream of water or use insecticidal soap.
- Cutworms: Cutworms are the larvae of certain moth species, and they feed on the stems of the plant, causing wilting and death of the affected area. To manage cutworms, handpick and remove them from the plant, or use an insecticide.
Regularly inspecting the plant and removing any pests can prevent their spread and reduce damage to the plant. Additionally, maintaining good garden sanitation can help prevent the occurrence of pests and diseases.
