Overview
Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. is a species of lupine that belongs to the Fabaceae family. It is a herbaceous perennial plant that is native to North America.
Common Names
This plant goes by several common names including subalpine lupine, Arctic lupine, and Robbin's lupine.
Appearance
The subalpine lupine is a flowering plant that grows up to 4 feet tall. It typically has a single erect stem with alternate compound leaves. The leaves consist of 5-10 leaflets that are elliptic to lanceolate in shape and are green on the upper surface and paler on the underside. The plant produces showy, dense spikes of flowers that are usually blue or purple, but can also be pink, white, or yellow. The fruit of the plant is a hairy legume that contains several seeds.
Uses
The subalpine lupine is an important plant for both ecological and agricultural purposes. It is a source of food for many animals, including bees, butterflies, and birds. It is also used in land restoration projects because it helps to improve soil conditions and prevent erosion. Additionally, it can be used as a forage crop for livestock, as it is high in protein.
Light Requirements
Lupinus arcticus var. subalpinus thrives in full sun to partial shade. This plant requires a minimum of six hours of direct sunlight per day. When grown in partial shade, ensure that it receives morning sun or dappled sunlight, creating an environment with bright but indirect light.
Temperature Requirements
The temperature requirement of Lupinus arcticus subalpinus varies depending on the season and the climate. The plant can tolerate a wide range of temperatures and can survive in areas with both warm and cool climatic conditions. The optimal temperature range during the growing season is between 10°C - 20°C (50°F - 68°F). However, Lupinus arcticus var. subalpinus can tolerate temperatures as low as -20°C (-4°F) during the dormant season.
Soil Requirements
Lupinus arcticus var. subalpinus grows well in well-drained soils with a pH range of 6.5 - 7.5. The soil should be rich in organic matter, loamy in texture and must provide adequate drainage. This plant cannot tolerate prolonged waterlogging during the growing season. It prefers soils that are fertile and hold moisture well. Ensure that the soil is not compact to prevent the occurrence of root rot.
Cultivation Methods
Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. grows well in areas with well-drained soil. It prefers slightly acidic to neutral soil pH levels. It is an exceedingly tough and resilient plant, capable of growing in a wide variety of soil types, including sandy, loamy, and clayey soils. One should ensure that the plant receives ample sunlight for optimal growth.Watering Needs
Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. requires moderate watering. Like other lupine plants, it has a deep taproot capable of reaching down into the soil to access water reserves. During the summer months, regular watering is essential for the plant to thrive. It is important to avoid overwatering as this plant does not do well in waterlogged soil.Fertilization
Though Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. is a self-sufficient plant that can fix its nitrogen from the air using root nodules, adding nitrogen-rich fertilizer is recommended. It is essential to use a balanced, slow-release fertilizer at the beginning of each growing season, which helps promote flowering and healthy vegetative growth.Pruning
Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. does not require regular pruning. However, to stimulate growth and increase blooms, deadheading by removing spent flower heads can be an effective technique. One should also remove any diseased, damaged, or dead plant material as soon as possible to avoid the spread of diseases that could affect the plant.Propagation of Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm.
Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. commonly known as the Arctic Lupine, is a perennial plant that belongs to the family Fabaceae. The plant is mostly found in Alaska and Western Canada, but it can also thrive in subalpine and alpine regions.
Seed Propagation
The most common propagation method of Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. is through seeds. The seeds of this plant can be directly sown in containers or in the ground during spring or fall. The ideal soil for these seeds is sandy and well-drained. The containers should be placed in a location that receives partial shade or full sunlight.
The seeds should be sown at a depth of about 1 inch and spaced 6-18 inches apart. They should be watered regularly but not overwatered. The germination of these seeds typically takes about 15-30 days.
Vegetative Propagation
Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. can also be propagated vegetatively through stem cuttings or division. Stem cuttings should be taken from the parent plant during its active growth period and rooted in sandy soil. The cuttings should be kept moist and in partial shade until they develop roots.
The plant can also be propagated through division. This should be done in early spring or fall. The parent plant should be carefully dug out, and the crowns should be separated into sections. Each section should be planted in a separate container or directly in the ground.
Care and Maintenance
Regardless of the propagation method used, Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. requires adequate care and maintenance. The plant prefers well-draining soil and regular watering. It should be fertilized annually with a balanced fertilizer. Deadheading the spent flowers can encourage the plant to produce more blooms.
With proper propagation and care, Lupinus arcticus S. Wats. var. subalpinus (Piper & B.L. Robins.) C.P. Sm. can be a beautiful addition to any garden or landscape.
Disease Management for Lupinus arcticus S. Wats. var. subalpinus
Lupinus arcticus S. Wats. var. subalpinus is generally a hardy plant and is not prone to many diseases. However, some diseases that might affect it include:
- Fungal Leaf Spot: Fungal leaf spot usually appears as brown or black spots on the leaves. These spots may merge, causing the leaves to turn yellow and fall off. To manage fungal leaf spot, remove the affected leaves and treat the plant with a fungicide.
- Crown Rot: Crown rot is a fungal disease that causes the plant's roots to rot. This usually happens in damp conditions. To manage crown rot, improve the drainage around the plant and remove any infected plant material.
Preventative measures such as good sanitation practices and maintaining proper growing conditions can help prevent these diseases from affecting the plant.
Pest Management for Lupinus arcticus S. Wats. var. subalpinus
Lupinus arcticus S. Wats. var. subalpinus is also fairly resistant to pests, but some common pests to watch out for include:
- Aphids: Aphids are tiny insects that suck the sap out of the plant, causing it to wilt and become distorted. To manage aphids, spray the plant with insecticidal soap or neem oil.
- Spider Mites: Spider mites are another pest that can cause the leaves to yellow and fall off. To manage spider mites, regularly spray the plant with water to keep the leaves clean and well-hydrated, and consider using a miticide.
Again, preventative measures are key to preventing these pest infestations. This includes keeping the plant healthy and properly watered, removing any dead or dying plant material, and regularly checking the plant for signs of pests.
