Origin
Lupinus excubitus M.E. Jones var. hallii (Abrams) C.P. Sm., commonly known as Hall's bush lupine, is a wildflower native to California and found typically in the Sierra Nevada mountain range and the San Gabriel Mountains. It usually grows at elevations between 4,000 and 9,000 feet and is known for its beautiful and showy display of flowers during the spring and summer months.
Common Names
Hall's bush lupine is commonly known by several other names including Hall's lupine, Sierra lupine, and bush lupine. The plant is also known as the "grape soda lupine" due to the grape soda-like fragrance of the flowers.
Uses
The plant is popular for its use in public and private wildflower gardens. It is also used for restoration in areas where native plants have been lost to large-scale development. The nectar provided by its flowers is a valuable food source for bees and other pollinators. Additionally, the plant has historical medicinal uses, with the California Native Americans using it as a treatment for skin ailments and stomach disorders.
General Appearance
Hall's bush lupine is a perennial herbaceous flowering plant that grows up to 3 feet high and wide. The plant has a bushy and rounded habit. The leaves of the plant are palmately compound, with 5 to 8 leaflets growing up to 4 inches long. The flowers of the Hall's bush lupine are blue, purple, or pink and grow in cylindrical clusters along a central spike. The plant produces fruit that is a legume, which contains a few seeds that are green when immature, but turn black when mature.
Light Requirements:
Lupinus excubitus M.E. Jones var. hallii grows well in full sun to partial shade. They require at least six hours of direct sunlight exposure for good growth and development. However, they will not do well in complete shade as it hinders photosynthesis and leads to spindly growth.
Temperature Requirements:
Lupinus excubitus M.E. Jones var. hallii grows well in a wide range of temperatures, but they thrive in cool to mild temperatures. During the growing season, the ideal temperature range is between 50–75°F, and they can tolerate colder temperatures as low as 25-30°F. Temperatures exceeding 90°F should be avoided as they can cause heat stress and damage to the plant.
Soil Requirements:
The plant grows best in well-drained soils with a neutral to slightly acidic pH level. A pH range of 6.0 to 7.5 is ideal for the plant's growth and development. Soil should be rich in organic matter, medium-textured, fertile, and should be able to retain water well. Sandier soils can also be used, but extra attention should be given to watering and nutrient levels as they have lower water and nutrient retention.
Cultivation Methods:
Lupinus excubitus M.E. Jones var. hallii (Abrams) C.P. Sm. is a perennial herb that is native to California and is commonly referred to as the Hall's lupine. The plant is known for its bluish-purple flowers that bloom in the late spring or early summer.
The plant prefers to grow in full sun to partial shade and in well-draining soil. It can be propagated through seed or vegetative cuttings. The recommended planting depth for seeds is about 1/4 inch.
Watering Needs:
Lupinus excubitus M.E. Jones var. hallii (Abrams) C.P. Sm. is drought-tolerant and can survive with minimal watering. It is important to avoid overwatering the plant as it can lead to root rot and other diseases. The plant can be watered deeply once a week during the growing season.
Fertilization:
Lupinus excubitus M.E. Jones var. hallii (Abrams) C.P. Sm. does not typically require fertilization. However, if the plant appears to be struggling or if it is being grown in poor soil, it might benefit from a slow-release fertilizer applied at the beginning of the growing season. Avoid using excessive amounts of nitrogen fertilizer, as it can cause the plant to produce more leaves and fewer flowers.
Pruning:
Pruning is not necessary for Lupinus excubitus M.E. Jones var. hallii (Abrams) C.P. Sm. However, to promote bushier growth, the plant can be pinched back after the first set of leaves appears. Deadheading the spent flowers can also encourage more blooms to form.
Propagation of Lupinus excubitus var. hallii
Lupinus excubitus var. hallii is commonly known as the Hall’s lupine or the bajada lupine. It is a native Californian plant that is found at elevations of 1,000 to 5,000 feet. Lupinus excubitus var. hallii can be propagated through different methods.
Seed Propagation
The easiest way to propagate this plant is through seed propagation. The seeds can be planted directly in the soil in early spring or fall after soaking them overnight in water. The soil should be well-drained, and the seeds should be planted at a depth of 1/8 inch and 12 inches apart to allow enough space for the plant's growth. The seedlings will emerge within 10 to 20 days, and they should be watered regularly to keep the soil moist until they establish themselves.
Cutting Propagation
Cutting propagation can also be used to propagate Lupinus excubitus var. hallii. This method involves taking cuttings from the stem and placing them in the soil. The cuttings should be taken in early spring, and they should be 3 to 4 inches long. Once planted, the soil should be kept moist until the cuttings root, which should take about 4 to 6 weeks.
Division Propagation
Division propagation can be used to propagate Lupinus excubitus var. hallii by dividing the root ball. This method should be done in the spring. The root ball should be dug up, and the plant should be gently separated from the clump using a sharp knife. Each division should have a minimum of three shoots and a healthy root system. Once separated, the divisions should be planted in well-drained soil and kept moist until they establish themselves.
Disease Management
One common disease that may affect the Lupinus excubitus var. hallii is root rot, caused by Phytophthora cinnamomi, a fungus-like organism. The disease attacks the roots, restricting the movement of water and nutrients, eventually leading to wilting and death of the plant. To manage the disease, it is essential to avoid overwatering the plant, provide adequate drainage and avoid planting in areas prone to waterlogging. If the infection is severe, it is best to uproot the affected plant and discard it to prevent the spread of the disease.
Powdery mildew is another disease that may occur on Lupinus excubitus var. hallii. The disease manifests as a white powdery coating on the leaves, inhibiting photosynthesis and leading to stunted growth. It is best to control the disease by planting resistant cultivars and maintaining appropriate watering practices. Some fungicides may also help manage powdery mildew, but it is essential to follow the instructions provided by the manufacturer and apply them as directed.
Pest Management
Aphids are a common pest that may attack Lupinus excubitus var. hallii. These small insects feed on the plant's sap, causing yellowing of the leaves and distortion of the plant's growth. To manage aphids, it is essential to monitor the plant regularly and use an insecticidal soap to control the infestation. Additionally, introducing natural predators of aphids, such as ladybirds and lacewings, can also help control the population.
The lupin plant aphids are another pest that may affect Lupinus excubitus var. hallii. These insects feed on the plant's leaves, causing yellowing and distortion of the leaves. The pests also excrete honeydew, leading to the growth of sooty mold fungi. To prevent the infestation of lupin plant aphids, it is essential to regularly monitor the plant and employ an integrated pest management approach. This may involve using insecticidal soap, releasing natural predators, and removing and spraying affected parts of the plant with water.
