Overview
Sorbus sitchensis M. Roemer var. grayi (Wenzig) C.L. Hitchc. is a species of plant from the Rose family, Rosaceae. This plant is native to western North America, including the Pacific Northwest region of the United States and parts of British Columbia in Canada. It is commonly known as the Sitka mountain ash or Gray's mountain ash, and is widely recognized for its use in both traditional and modern herbal medicine.Description
Sorbus sitchensis var. grayi is a small to medium-sized deciduous tree that grows up to 15 meters tall. It has a straight trunk with a thin, irregular crown composed of slender branches. The leaves are alternate and pinnately compound, with 11 to 17 leaflets that are elliptic to oblong in shape and sharply serrated along the edges. The leaflets are dark green in color above and paler below, and turn a brilliant red or orange in the fall. The flowers are small, white, and arranged in large clusters that bloom in early summer. The fruit is a small, round pome that is orange to red in color and ripens in late summer.Common Names
Sorbus sitchensis var. grayi is commonly known by several other names depending on the region and language. Besides Sitka mountain ash and Gray's mountain ash, it is also referred to as Western mountain ash, Oregon mountain ash, Skookum apple, and Pigeon berry.Uses
The fruit of Sorbus sitchensis var. grayi has been used extensively by various indigenous groups in the Pacific Northwest. They used the berries to make preserves, juices, and pemmican, a traditional food made from dried meat, fat, and fruit. The bark and leaves of the plant were used for medicinal purposes, as they contain tannins, flavonoids, and other compounds that have anti-inflammatory, antioxidant, and analgesic effects. Today, Sorbus sitchensis var. grayi is primarily used as an ornamental plant in gardens and landscapes. Its attractive foliage and showy flower clusters make it a popular choice for parks, streets, and private gardens. The fruit is also a favorite food source for birds, including grouse, cedar waxwings, and robins, making it a valuable plant for wildlife habitat.Light Requirements
Sorbus sitchensis M. Roemer var. grayi grows in full sun to partial shade. When exposed to full sun, the tree is often smaller and has a more dense and compact shape. In partial shade, the plant tends to grow taller and more open.
Temperature Requirements
This plant can tolerate a wide range of temperatures, but it thrives in cooler conditions. In its natural habitat, it is found in regions with mild summers and cool, moist winters. It can tolerate temperatures below freezing and is capable of surviving in areas with heavy snowfall. Sorbus sitchensis M. Roemer var. grayi does not do well in areas with hot, dry summers.
Soil Requirements
When it comes to soil, Sorbus sitchensis M. Roemer var. grayi prefers well-drained, moist soil that is slightly acidic. It can grow in a variety of soil types, including sandy loam, silt loam, and clay loam. It can also grow in rocky soils, as long as there is enough soil for the roots to anchor themselves. The plant does not do well in areas with heavy clay soil or poor drainage. It also prefers soils that are rich in organic matter.
Cultivation
The Sorbus sitchensis M. Roemer var. grayi is a deciduous tree that grows well in a wide range of soils from sandy loam to heavy clay with good drainage. Plant this tree in a spot that receives full sun to partial shade. It is an extremely cold-hardy tree, tolerating temperatures down to -40°F. If you live in a region with harsh winters, this tree is perfect for your garden.
Watering Needs
Watering is essential to ensure the survival and growth of your Sorbus sitchensis M. Roemer var. grayi tree. Newly planted trees need regular watering, but once established, they are very drought tolerant. As a general rule, water your tree deeply once a week during the growing season. Ensure the soil is moist about 6-8 inches deep. Reduce watering during fall to harden off the wood before the onset of winter.
Fertilization
Apply fertilizer during spring to boost growth and improve nutrient uptake. The Sorbus sitchensis M. Roemer var. grayi tree responds well to fertilizers rich in phosphorus and potassium since they promote root and shoot growth. You may choose to use compost or well-rotted manure instead of fertilizers. Apply it around the tree's base up to the drip line. Avoid the trunk, as it may damage the bark and cause disease.
Pruning
Pruning is essential to maintain the Sorbus sitchensis M. Roemer var. grayi tree's size and shape. Prune in late winter when the tree is dormant, removing only dead, diseased, or damaged branches. It is a low maintenance tree that requires minimal pruning. Pruning should not exceed 25% of the tree's canopy since it may lead to tree stress and decline.
Propagation of Sorbus sitchensis M. Roemer var. grayi (Wenzig) C.L. Hitchc.
Sorbus sitchensis M. Roemer var. grayi (Wenzig) C.L. Hitchc., commonly known as Sitka mountain ash, is a small deciduous tree that is native to the coastal regions of Alaska and British Columbia. The tree produces clusters of berries that are highly attractive to birds and wildlife. Propagation of the Sitka mountain ash can be achieved through different methods such as seed propagation and vegetative propagation.
Seed Propagation
Seed propagation is the most common method of propagating the Sitka mountain ash. The seeds require a period of cold stratification to germinate successfully. The seeds can be stratified by placing them into a container of moist sand or vermiculite and storing them in the refrigerator at 2-4° Celsius for 90-120 days. After stratification, the seeds are sowed into a growing medium and kept in a warm and bright location. The seedlings can be transplanted after a year or two.
Vegetative Propagation
Vegetative propagation is an alternative method of propagating the Sitka mountain ash and involves rooting cuttings from a mature healthy tree. Hardwood cuttings of 6-8 inches (15-20 cm) long with a diameter of ½ inch (1.3 cm) are collected during the dormant season between late fall and mid-winter. The cuttings are then dipped into a rooting hormone and planted into a well-draining growing medium and kept in a warm, moist, and bright location. The cuttings will develop roots within 6-12 months and can be transplanted outdoors once they have hardened off.
Disease Management
Sorbus sitchensis M. Roemer var. grayi is generally tolerant to most common diseases. However, there are a few fungal diseases that can affect this plant:
- Cedar-Apple Rust: The fungal disease appears as round, yellow spots on the leaves. Rust pustules can be seen on the lower surface of the infected leaves. To manage this disease, remove the infected leaves, keeping the area below the tree clean, and avoid planting junipers nearby.
- Powdery Mildew: This disease is characterized by the appearance of white, powdery coating on plant leaves. To manage this disease, improve air circulation by pruning the plant, water at the base of the plant, and apply a fungicide.
- Fire Blight: The symptoms of the disease are wilting and dieback of the plant. The infected branches appear to have a scorched appearance. To manage this disease, remove infected parts of the plant as soon as possible and sterilize your pruning tools before using them on healthy plants.
Pest Management
Sorbus sitchensis M. Roemer var. grayi is also generally resistant to pest infestations. However, there are a few pests that may affect this plant:
- Spider Mites: These pests appear as tiny red spots on the leaves, which may also become stippled and discolored. To manage them, use insecticidal soap, introduce natural predators such as lady beetles, keep the soil moist, and improve air circulation by pruning the plant.
- Aphids: These pests appear as tiny, pear-shaped bugs on the undersides of leaves, causing yellowing and distorted growth. To manage them, use an insecticidal soap, introduce natural predators such as lady beetles, and prune the plant to improve air circulation.
It is always important to monitor the plant regularly. If you detect any signs of disease or pests, it is essential to act quickly and manage the issue to prevent significant damage to the plant.
