Origin
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm., commonly known as Siskiyou lupine, is a perennial herbaceous plant that is native to western North America, specifically found in California, Oregon, and Washington.
Common Names
The Siskiyou lupine has a few common names, including broadleaf lupine, cousins, patsy’s lupine, purple-flowered broadleaf lupine, and simply as lupine in some cases.
Uses
The Siskiyou lupine is an important plant for pollinators because of its high nectar and pollen production. This plant is also used in restoration projects to reintroduce native vegetation to disturbed or damaged ecological systems, especially in areas that have experienced fires. Additionally, the seeds of the Siskiyou lupine are edible and sometimes used as a food source by indigenous people.
General Appearance
The Siskiyou lupine grows up to 120 centimeters tall, with stems that are densely covered with white hairs. The leaves are palmately compound with five to thirteen leaflets that are elliptic to oblong in shape. The inflorescence is a cylindrical cluster of pea-like flowers, varying in shade from violet to deep blue and growing up to 22mm long. The plant produces dehiscent fruits that contain several smooth seeds that are colored with various shades of mottled or solid brown.
Growth Conditions for Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm.
Light: Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. requires full sun exposure for optimal growth. It can tolerate partial shade, but it may lead to smaller plant size, reduced number of flowers, and increased susceptibility to disease.
Temperature: This plant typically grows in areas with a Mediterranean climate, characterized by mild wet winters and hot dry summers. The ideal temperature range for Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. is between 55-75°F (13-24°C). It can tolerate temperature extremes, but growth may be stunted, and flowering may be reduced.
Soil: Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. prefers well-draining soils with a pH range of 5.5-7.0. It can grow in different soil types, such as sandy, loamy, or clay soils, as long as they are well-draining. It is also adapted to soil low in fertility and can fix nitrogen from the atmosphere through its association with rhizobia.
Cultivation
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. is a beautiful, perennial herb that thrives in full sun and well-drained soil. It prefers alkaline soil but will tolerate a pH as low as 5.5. It is a hardy plant that adapts well to varying soil types, including clay, loam, and sand. It is best to sow Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. seeds in the fall directly into your garden beds, as the plant requires a period of cold stratification to break dormancy. Once the seeds germinate, thin the seedlings to a spacing of about 12-18 inches to allow room for the mature plants to grow.Watering Needs
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. prefers moist but well-drained soil. When grown in the garden, it should be watered regularly, but caution should be taken not to overwater the plant. Overwatering can lead to root rot, so ensure that the soil is not waterlogged. In times of drought, it is crucial to water the plant deeply, allowing the water to seep through the soil and reach the plant's roots. Before watering, always check the soil's moisture level to avoid overwatering or underwatering.Fertilization
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. is a nitrogen-fixing plant, and therefore, it does not require excessive fertilization. However, it is recommended to fertilize the plant annually with a balanced, slow-release fertilizer in the springtime when new growth starts. Alternatively, it is also possible to feed the plant with compost tea or a liquid fertilizer made from kelp or fish emulsion. Fertilization is not recommended during hot and dry periods, as it may damage the plant.Pruning
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. does not require regular pruning; however, deadheading is necessary to promote continuous blooming. Deadheading is the process of removing spent flowers before they can mature and produce seed. Additionally, it is recommended to remove any dead or diseased foliage to maintain the plant's overall health and appearance. Late season pruning should be avoided, as it can interfere with the development of the following year's growth.Propagation of Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm.
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. can be propagated through several methods. These are:
Seed propagation
The easiest and most practical way of propagating Lupinus bicolor is through seed propagation. Collect the seeds from the pods just before they open. Keep the seeds in a cool and dry place until ready to plant. Once you are ready to plant, you may soak the seeds for 24 hours to hasten germination. Plant the seeds in well-drained soil and water them regularly. Seedlings should emerge after 2 to 3 weeks.
Cutting propagation
Lupinus bicolor can also be propagated through cuttings, although this method is less common. Collect cuttings in the spring from the younger branches. Make sure the cutting has at least two nodes. Dip the cut end into rooting hormone and plant in a well-drained soil mix. Keep the soil moist and warm, and roots should form in a few weeks. Once the cutting has established roots, transplant to a larger pot or directly into the garden.
Division
Division is another method of propagating Lupinus bicolor. Peat moss and other organic matter will help create a favorable environment for the roots. Spring and fall are the best times for dividing plants. Dig up the plant and divide it into smaller parts. Replant the smaller parts into well-draining soil and keep well watered. The division method works best on well-established plants that are at least two years old.
Disease Management
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. can be susceptible to various diseases that can affect its growth and production. Some of the common diseases include:
- Anthracnose: This disease can cause wilting of the leaves and stems. Regular fungicide applications can help in controlling the disease.
- Bacterial Blight: It causes the development of water-soaked spots on the leaves which turn brown later on. Copper-based fungicides can be applied to reduce the spread of the disease.
- Fusarium Wilt: This disease causes the yellowing and wilting of the leaves. Fungicide treatments can help control the spread of the disease.
To manage diseases in Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm., it is essential to maintain good field hygiene by removing plant debris and infected plant parts. Regular inspection of the plant for early signs of disease can also help prevent the spread of disease. Chemical and biological controls can also be used to manage diseases effectively.
Pest Management
Lupinus bicolor Lindl. ssp. umbellatus (Greene) D. Dunn var. umbellatus (Greene) C.P. Sm. can face pest problems, which can affect its growth and yield. Here are some common pests that can affect the plant:
- Aphids: These insects can cause yellowing, wilting and stunted growth of the plant. The application of insecticides or the use of natural predators like ladybugs can effectively control aphid infestations.
- Cutworms: These pests can chew off the seedlings at the soil level. The use of collars around the seedlings can help prevent cutworm infestations.
- Snails and Slugs: These pests can cause damage to the young seedlings. Handpicking or the use of snail and slug baits can control their population.
Regular scouting and monitoring of the plant can help detect pest infestations early. The use of cultural practices like crop rotation, intercropping, and proper field sanitation can also prevent the spread of pests. The use of chemical control methods should be used as a last resort.
