Plant Description
Arnica louiseana Farr var. frigida (C.A. Mey. ex Iljin) Welsh is a perennial plant that is part of the Asteraceae family. It is a subspecies of Arnica louiseana and is commonly known as Arctic Mountain Arnica or Frigid Arnica.
The plant grows from a rosette of basal leaves that are typically 10-15 cm long. The stem grows to typically 10-35 cm tall and is usually hairy. The leaves are opposite, and their shape varies from spatulate to elliptic, with a length of up to 7 cm and a width of up to 2 cm.
The flowers grow in terminal heads that typically contain 1-4 flowers. The heads are usually 2.5-5 cm in diameter. The involucre bracts are purplish-brown in color, and the ray florets are typically yellow.
Plant Origin
Arnica louiseana Farr var. frigida is native to the Arctic regions of North America, specifically in Alaska and the Yukon. The plant also grows in some parts of Canada, including the Northwest Territories and Nunavut.
Common Names
The plant is commonly known as Arctic Mountain Arnica or Frigid Arnica. In Alaska, it is also called the Arctic Leopard’s Bane or the Arctic Wolf’s Bane.
Plant Uses
The plant has a long history of use in traditional medicine for various ailments, including sprains, bruises, and sore muscles. The roots and leaves contain several active compounds, including helenalin and dihydrohelenalin, which are known to have anti-inflammatory properties.
In addition to its medicinal properties, Arnica louiseana Farr var. frigida is also used as an ornamental plant in some areas. Its stunning yellow flowers and unique appearance make it a popular addition to rock gardens and alpine gardens.
Light Requirements
The Arnica louiseana var. frigida plant requires full sunlight for its growth. The plant must be exposed to at least six hours of direct sunlight every day. If the plant does not receive adequate sunlight, it may fail to bloom properly.
Temperature Requirements
The Arnica louiseana var. frigida plant is a cold-hardy plant that grows best in cool temperatures. The plant can tolerate extreme cold temperatures and can thrive in temperatures as low as -10°C. The plant's optimum growth temperature is between 16-22°C. Too much heat can cause the plant to suffer, and it may even die in very high temperatures.
Soil Requirements
The Arnica louiseana var. frigida plant grows best in well-draining soil that is rich in organic matter. The soil should be slightly acidic, with a pH range of 5.5-6.5. The plant requires moist soil but not waterlogged soil; water should not be allowed to remain on the surface. The plant's roots require good air circulation, so the soil must not be compacted. Soil should be replenished with compost every year to provide adequate nutrients for the plant's growth.
Cultivation Methods
Arinica Louiseana Farr var. frigida grows best in well-drained soil and partial shade. If planting in a pot, choose a container with good drainage holes and use a mixture of peat, sand, and perlite in equal parts to prevent root rot. The plant can also tolerate dry conditions, but avoid extremely hot, dry summers.
Watering Needs
Arnica Louiseana Farr var. frigida prefers slightly moist soil but can tolerate periods of drought. Water the plant regularly during the growing season, ensuring the root ball does not dry out. Avoid overwatering, as it can lead to root rot.
Fertilization
The plant does not require heavy fertilization. Apply a balanced, slow-release fertilizer in early spring before new growth appears. Alternatively, use compost or well-rotted manure to feed the plant once a year, but avoid applying too close to the stem.
Pruning
To maintain the desired shape, prune Arnica Louiseana Farr var. frigida in late winter or early spring before new growth appears. Prune back up to one-third of the plant's total height as needed. Cut back any damaged or dead stems as soon as you notice them.
Propagation of Arnica louiseana Farr var. frigida
Arnica louiseana Farr var. frigida (C.A. Mey. ex Iljin) Welsh, commonly known as Louise's arnica, is a flowering plant that is native to North America. It is found in alpine and subalpine areas, growing in wet meadows, tundra, and along streams.
Propagation Methods
One common method of propagating Arnica louiseana Farr var. frigida is by seed. The plant produces small, hairy seeds that are dispersed by wind or water. To propagate the plant using seed, it is best to collect the seeds in the fall and sow them in the fall or early spring. The seeds do not require any special treatment before sowing, but they should be placed on the surface of damp soil and covered lightly with a thin layer of soil. The soil should be kept damp until the seedlings emerge, which can take up to several weeks.
Another method of propagating Arnica louiseana Farr var. frigida is by division. The plant produces clusters of rhizomes that can be divided in the spring or fall. To divide the plant, carefully dig up the clump and cut it into smaller sections, ensuring that each section has several shoots and some healthy roots. Replant the sections in well-draining soil and keep them moist until they become established.
Growing Arnica louiseana Farr var. frigida by cuttings is possible, but it is not a commonly used method. If you want to propagate the plant using cuttings, take softwood cuttings in the spring and root them in a mixture of sand and peat moss. Keep the rooting medium moist and place the cuttings in a shaded area until they develop roots and new growth.
Disease Management
Arnica louiseana Farr var. frigida is prone to several diseases that can affect its growth and yield. It is essential to take timely measures to manage and prevent these diseases to ensure healthy plant growth. The common diseases that can affect the plant include:
Root Rots
Root rots are among the most prevalent diseases that affect the Arnica louiseana Farr var. frigida. It is caused by fungi that attack the roots, leading to rotting and eventually death. To manage root rots, avoid planting in poorly drained soils and ensure that the soil is well-aerated. In case of an infection, remove and destroy the affected plants and their root balls.
Fungal Leaf Spots
Fungal leaf spots are characterized by the presence of black, circular spots on the leaves. The disease is caused by a fungus that thrives in moist and humid conditions. To manage fungal leaf spots, ensure proper air circulation by spacing the plants and avoiding overhead watering. Use fungicides to treat infected plants.
Powdery Mildew
Powdery mildew is a common disease that affects the Arnica louiseana Farr var. frigida. It is characterized by the presence of powdery white spots on the leaves. The disease is caused by fungi that thrive in high humidity and poorly ventilated environments. To manage powdery mildew, ensure proper air circulation, reduce humidity levels by avoiding overhead watering, and use fungicides.
Pest Management
In addition to diseases, Arnica louiseana Farr var. frigida is also prone to pest attacks that can affect its growth and yield. It is essential to take timely measures to manage and prevent these pests to ensure healthy plant growth. The common pests that can affect the plant include:
Aphids
Aphids are small, pear-shaped insects that attack the plant's leaves and stems by feeding on the sap. They also transmit viral diseases that can severely damage the plant. To manage aphids, use insecticidal soap or neem oil spray to control their population, and encourage natural predators such as ladybugs and lacewings.
Mites
Mites are small, spider-like insects that attack the plant's leaves, causing yellowing and leaves' stippling. They thrive in hot, dry conditions, making them prevalent in arid areas. To manage mites, spray the plants with water to increase humidity levels and apply insecticidal soaps or neem oil.
Slugs and Snails
Slugs and snails attack the plant's leaves and stems, causing extensive damage. They prefer moist and cool environments, making them prevalent in wet areas. To manage slugs and snails, remove any debris or hiding places, apply diatomaceous earth, and use copper barriers to prevent their movement.
