Overview
Lupinus argenteus Pursh var. parviflorus (Nutt. ex Hook. & Arn.) C.L. Hitchc. is a sub-species of Lupinus argenteus, a plant endemic to western North America. This plant is commonly known as the silver lupine, or the silky lupine. It is a perennial plant that belongs to the Fabaceae family, which is also known as the legume, pea or bean family.
Origin
Silver lupine is native to western North America, ranging from British Columbia to California, and can be found in various habitats such as meadows, dry slopes and open woods.
Common names
Silver lupine is commonly known as the silver lupine or the silky lupine due to its silvery hairs that cover the plant's leaves and stem. Other common names include silky scorpionweed, Douglas' silver lupine, and dwarf silver lupine.
Appearance
Silver lupine is a perennial plant that can grow up to 60cm in height. The leaves are alternate, palmately compound, and have 5-10 leaflets. The plant's stem is covered with silvery hairs. The flowers are arranged in cylindrical spikes that are 5-10cm long. The flowers have five petals, which are typically blue to purple in color. The plant produces a pod that contains seeds.
Uses
Silver lupine has various uses, including ecological and medicinal purposes. The plant is used in ecological restoration as it is nitrogen-fixing and can help to improve soil quality. The plant is also used to provide food and habitat for various pollinators, including bumblebees, butterflies, and moths. Additionally, the plant is used in traditional medicine to treat various ailments such as fever and digestive disorders.
However, it's important to note that Lupinus argenteus can be toxic to livestock as it contains alkaloids that can cause birth defects and neurological problems.
Light Requirements
Lupinus argenteus Pursh var. parviflorus is a plant species that thrives in areas with full sun exposure. It is not adapted to grow in shaded environments. Therefore, it is recommended to plant them in areas with direct sunlight exposure, typically for at least six hours each day.
Temperature Requirements
The temperature requirements of Lupinus argenteus Pursh var. parviflorus vary depending on the stage of growth. During the germination stage, the ideal temperature for the seed to sprout ranges between 10°C to 15°C. After the seedling emerges above the soil surface, the optimum temperature range for growth is between 16°C to 25°C. Mature plants can tolerate temperatures between 25°C to 30°C.
Soil Requirements
Lupinus argenteus Pursh var. parviflorus thrives in well-draining, sandy, and gravelly soils. It can grow in a pH range of 4.7 to 7.8, with a preference for mildly acidic soils. Adequate soil moisture is essential for optimum plant growth; thus, provide enough water to maintain the soil moist, but not waterlogged. This plant species is not adapted to grow in heavy soils, such as clay or compacted soils.
Cultivation methods for Lupinus argenteus Pursh var. parviflorus
Lupinus argenteus Pursh var. parviflorus (Nutt. ex Hook. & Arn.) C.L. Hitchc. is a hardy, drought-resistant perennial plant that is native to the western United States. It is commonly known as silver lupine or silvery lupine and is grown for its attractive silver-gray foliage and stunning bluish-purple flowers. If you wish to cultivate this plant, you must consider the following methods:
- It prefers full sun but can tolerate partial shade.
- The soil must be well-drained and moderately fertile, with a pH between 6.0 and 7.5.
- It is best to sow seeds directly into the ground in the fall or early spring.
- It can also be propagated through stem cuttings or divisions.
Watering needs for Lupinus argenteus Pursh var. parviflorus
Proper watering is essential for the growth and survival of Lupinus argenteus Pursh var. parviflorus. Watering needs vary depending on the climate, soil type, and plant size.
- It prefers well-drained soil, so make sure the soil is not waterlogged.
- Young plants require regular watering until they become established.
- Once established, silver lupine can tolerate periods of drought.
- During prolonged dry spells, it may need supplemental watering.
- Watering should be done early in the morning or late in the evening to avoid evaporation.
Fertilization of Lupinus argenteus Pursh var. parviflorus
Lupinus argenteus Pursh var. parviflorus is not a heavy feeder and can grow well without fertilization. However, adding nutrients can improve blooming and growth. Here are some tips for fertilizing silver lupine:
- Use a balanced fertilizer, such as a 10-10-10 or 15-15-15 formula.
- Apply the fertilizer once in early spring and once in early summer.
- Use a slow-release fertilizer to avoid burning the roots.
- Do not over-fertilize, as it can lead to weak growth and fewer flowers.
Pruning of Lupinus argenteus Pursh var. parviflorus
Pruning silver lupine is not necessary for its survival, but it can improve its appearance and prolong its life. Here are some pruning tips for Lupinus argenteus Pursh var. parviflorus:
- Deadhead spent flowers to promote new blooms.
- Pinch back the tips of new growth in the spring to encourage bushier growth.
- Remove any dead or diseased foliage or stems to prevent the spread of disease.
- Delay pruning until late summer or fall to allow the plant to store food reserves for the winter.
Propagation Methods:
Lupinus argenteus Pursh var. parviflorus (Nutt. ex Hook. & Arn.) C.L. Hitchc. can be propagated both by seeds and vegetative cuttings.
Propagation by Seeds:
Seeds can be collected from the plant once the pods are mature. Crush the pods to release the seeds. The seeds can be directly sown in the garden bed or in pots. Sow the seeds at a depth of 1-2 inches and cover with soil. Keep the soil moist and place the pots in a sunny location. Seeds usually germinate within 14 to 30 days after sowing.
Propagation by Vegetative Cuttings:
Vegetative cuttings can be taken in late spring or early summer. Take 3 to 4 inches stem cuttings from the plant. Remove the lower leaves and dip the cuttings in rooting hormone. Plant the cuttings in moist soil in the pots or directly in the garden bed. Keep the soil moist and place the pots in a sunny location. The cuttings will start to root within 2 to 3 weeks.
Disease Management
Lupinus argenteus Pursh var. parviflorus (Nutt. ex Hook. & Arn.) C.L. Hitchc. is susceptible to fungal diseases such as root rot, stem rot, and leaf spot. To manage these diseases, it is important to maintain good sanitation practices, including removing infected plant debris and disinfecting tools between uses. Additionally, proper watering and drainage can help prevent the development and spread of fungal diseases. Fungicides may also be effective in managing these diseases, but it is important to carefully follow label instructions for proper use and application.
Pest Management
Lupinus argenteus Pursh var. parviflorus (Nutt. ex Hook. & Arn.) C.L. Hitchc. is susceptible to a variety of pests, including aphids, spider mites, and snails. Aphids and spider mites can be managed through regular monitoring and the use of insecticidal soaps or oils. Snails can be deterred by removing debris and other hiding places around the plants, and using physical barriers such as copper tape or mesh. It is important to avoid using broad-spectrum pesticides that can harm beneficial insects and disrupt the ecosystem.
