Origin
Lupinus caudatus Kellogg var. subtenellus C.P. Sm. belongs to the family of Fabaceae and is a sub-species of Lupinus caudatus which is native to western North America.
Common Names
The plant is commonly referred to as Tailcup Lupine and Slender Lupine.
General Appearance
The Tailcup Lupine plant is an herbaceous perennial that can grow up to 60cm in height. It has a slender and erect stem that is hairy throughout. The leaves are compound and contain 5 to 7 leaflets with a linear shape. The flowers, which bloom from May to August, are densely packed on a long inflorescence. The flowers are blue or purple in color and have a white spot on the upper petal. The fruit of the plant is a linear legume which splits into 2 valves to release the seeds.
Uses
The Tailcup Lupine has a number of uses. Firstly, it is a common ornamental plant as it adds aesthetic value to a garden with its beautiful flowers. Secondly, it is used as a food crop by indigenous people in parts of North America. The seeds are ground into a flour and used to make bread, porridge and cakes. Finally, the plant has ecological significance as it is a valuable source of nitrogen fixation in soil, thereby improving soil fertility.
Light Requirements
Lupinus caudatus var. subtenellus thrives in areas with plenty of sunshine. It prefers full sunlight and can tolerate partial shade but may not grow as well.
Temperature Requirements
Lupinus caudatus var. subtenellus can tolerate cold temperatures and prefers high elevations. However, it also tolerates warm temperatures, especially during the growing phase. The optimal temperature range for its growth is between 15°C and 20°C.
Soil Requirements
Lupinus caudatus var. subtenellus prefers well-draining soils that are fertile and rich in nutrients. The soil pH should range between slightly acidic and neutral (6.0 to 7.5). Additionally, the plant is adapted to grow in soils that are low in Nitrogen. The plant also prefers sandy soils over clayey soils as it is better for its root system and general health.
Cultivation methods of Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
Lupinus caudatus Kellogg var. subtenellus C.P. Sm. is a hardy plant that can be grown as an annual or a perennial. It prefers well-drained soil and a sunny location. The plant can be propagated by seeds that are sown directly in the ground after the danger of frost has passed. Alternatively, seeds can be started indoors 6-8 weeks before planting outdoors.
Watering needs of Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
The plant requires moderate watering, with the soil kept consistently moist but not waterlogged. It is tolerant of drought once established, but prolonged dry periods can adversely affect the plant's growth and flowering. To maintain optimal growth and flowering, it is recommended to water the plant regularly, especially during periods of extended dryness.
Fertilization of Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
The plant does not require heavy fertilization, but a light application of a balanced fertilizer once or twice during the growing season can encourage healthy growth and blooming. Over-fertilization can lead to a weak stem and excessive foliage at the expense of blooms, so it's important to avoid overfeeding the plant.
Pruning of Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
The plant does not require pruning, but deadheading spent blooms can encourage further flowering. It's also recommended to remove any yellow, damaged, or diseased foliage throughout the growing season to promote plant health and aesthetics. In areas with harsh winters, the plant can be cut back to the ground in autumn to promote new growth in the spring.
Propagation of Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
Lupinus caudatus Kellogg var. subtenellus C.P. Sm. is commonly propagated by seed. Seeds can be collected from fully matured individuals during the fall season. These seeds can be directly sown in the field or started indoors for later transplanting.
When starting seeds indoors, they should be soaked in water for 24 hours before planting. Sow the seeds in a well-drained potting mix, water lightly, and place them in a warm and bright location. Germination can take up to 30 days and should be watered sparingly to prevent fungal growth and damping off.
Seedlings should be transplanted to a larger container when they have developed three to four sets of true leaves. The plant can be transferred to the desired site when it has grown to a height of 6-8 inches and has established a strong root system.
Lupinus caudatus Kellogg var. subtenellus C.P. Sm. can also be propagated through stem cuttings and division. However, these methods are not as commonly used as seed propagation due to the species' fragile root system.
Stem cuttings can be taken during the summer months when the plant is actively growing. Use clean pruning shears to cut a stem with two to three nodes and remove the lower leaves. Dip the cutting in rooting hormone and plant in a well-drained potting mix. Keep the cutting moist by covering it with a plastic bag or cloche, and place it in a brightly lit, warm location. Roots should develop within a few weeks, and the plant can be transplanted once they have established.
Division involves separating the roots and shoots of a mature plant and replanting them. However, this method can be challenging due to the species' delicate root system.
Disease Management for Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
One of the main diseases that can affect Lupinus caudatus Kellogg var. subtenellus C.P. Sm. is root rot, caused by the fungus Fusarium solani. Symptoms include wilting, yellowing, and root decay. To manage this disease, it is important to provide good drainage and avoid overwatering. Fungicides can also be used, but they are not always effective.
Another disease that can affect this plant is powdery mildew, caused by the fungus Erysiphe cichoracearum. Symptoms include a white powdery substance on the leaves and stems, as well as stunted growth. To manage this disease, remove and destroy infected plant parts and improve air circulation around the plant. Fungicides can also be used.
Pest Management for Lupinus caudatus Kellogg var. subtenellus C.P. Sm.
One of the main pests that can affect Lupinus caudatus Kellogg var. subtenellus C.P. Sm. is aphids. These small insects can cause curling and yellowing of leaves, as well as stunted growth. To manage aphids, use a strong stream of water to wash them off the plant, or use insecticidal soap or neem oil. Ladybugs and lacewings can also be introduced to the garden as natural predators of aphids.
Another pest that can affect this plant is the lupin seed weevil, which feeds on the seeds of the plant. To manage this pest, inspect the seeds for signs of damage before planting and remove any infested seeds. Insecticidal sprays can also be used, but they should be applied early in the growing season to be effective.
