Overview of Fraxinus pennsylvanica Marsh. ssp. oregana
Fraxinus pennsylvanica Marsh. ssp. oregana, commonly known as Oregon ash, is a deciduous plant species in the Oleaceae family. It is endemic to western North America, including parts of the United States and Canada. This tree is closely related to the green ash (Fraxinus pennsylvanica), but it is distinguishable due to minor morphological and genetic differences.
Description of Fraxinus pennsylvanica Marsh. ssp. oregana
The Oregon ash tree can grow up to 80 feet tall with a trunk diameter of three feet. It has a rounded crown, with a straight, slender bole usually free of branches for up to 40 feet. The tree's bark is initially smooth and brown, but it becomes more rough and grey with age. The leaves of the Oregon ash are deciduous and normally comprised of five to nine leaflets. These leaves are green during the summer, turning yellow before falling off for the winter.
The tree is dioecious, meaning there are separate male and female trees. The female trees produce small, winged fruits known as samaras, which are dispersed by wind and water.
Uses of Fraxinus pennsylvanica Marsh. ssp. oregana
Traditionally, the Oregon ash was treasured by Indigenous peoples for its medicinal and practical uses. The inner bark was used to produce twine and baskets, while the leaves and bark were utilized in poultices to relieve inflammation and pain. The wood was also regarded for its durability and strength as it was used to make canoe paddles and hunting weapons.
Today, the Oregon ash is commonly used in horticulture as a shade tree and for its vibrant fall foliage. The lumber is also utilized for furniture construction, flooring, and cabinetry due to its robust nature. It is also commonly used in ecological restoration projects, acting as a habitat for various animals and stabilizing riparian areas.
Light Requirements
The Fraxinus pennsylvanica Marsh. ssp. oregana (Wesmael) G.N. Mill. requires full to partial sunlight exposure for optimal growth and development. The plant can grow in shaded areas but may mature slower. At the same time, it is important to protect the plant from strong winds and excessively hot or dry conditions, particularly during its establishment period.
Temperature Requirements
The plant is adapted to grow in cold to temperate climates and can withstand low temperatures of up to -50°F (-45°C). It thrives in areas with an average temperature range of 55°F-75°F (13°C-24°C) and may experience some heat stress at temperatures above 85°F (29°C). The ideal temperature range for the plant to grow and develop well is 60°F-70°F (15°C-21°C).
Soil Requirements
The Fraxinus pennsylvanica Marsh. ssp. oregana (Wesmael) G.N. Mill. prefers moist and well-drained soils, such as loamy, sandy loam, and silty loam soils, with a neutral soil pH of 6.0-7.5. The plant can also tolerate slightly acidic to slightly alkaline soils. The soil should be rich in nutrients, organic matter, and humus, with good water retention capacity. The plant can also grow in poorly drained soils, although this may lead to stunted growth and poor development. The plant is adapted to grow well in alluvial soils and gravely sandy loams, which can allow for optimal growth and development.
Cultivation Methods
Fraxinus pennsylvanica Marsh. ssp. oregana (Wesmael) G.N. Mill. is commonly known as Oregon ash and is native to western North America. It is a hardy tree and can tolerate a wide range of soil conditions. The tree is commonly propagated through seeds or cuttings.
For successful germination, it is advisable to stratify the seeds for two months in a moist medium before planting them in a well-draining soil mix. The ideal temperature for growth should be between 60°F and 75°F, and the tree should be planted in a spot with full sun exposure.
Watering Needs
Fraxinus pennsylvanica Marsh. ssp. oregana (Wesmael) G.N. Mill. has moderate water needs, and regular watering is recommended to keep the soil moist but not waterlogged. Watering frequency can be adjusted based on the soil type and the tree's age and size.
A layer of mulch can help retain soil moisture and keep the tree's roots cool during hot weather. Avoid overhead watering as it can lead to fungal infections.
Fertilization
Oregon ash trees have moderate fertility requirements and respond well to balanced fertilizers. Fertilizer application should be done twice a year, during the spring and fall seasons.
A soil test can help determine the appropriate amount of fertilizer to apply. Over-fertilizing can lead to accelerated growth, weak branches, and fewer flowers and fruits.
Pruning
Pruning is an essential aspect of Oregon ash tree care. It promotes tree health, enhances its appearance, and corrects structural problems. The best time to prune the tree is during the dormant season, i.e., late fall or winter.
Regularly remove weak, damaged and dead branches, any crossing or rubbing branches, and any sprouts that form on the base of the trunk. Ensure that the pruning tools are clean and sterile to avoid any spread of fungal infections.
Propagation Methods for Fraxinus Pennsylvanica Marsh. ssp. Oregana
Fraxinus Pennsylvanica Marsh. ssp. Oregana is commonly known as the Oregon ash and is a deciduous tree native to the Pacific Northwest region of North America. It can reach a height of up to 25 meters and is known for its tolerance of wet soils, making it an ideal tree for riparian restoration projects.
Propagation of Fraxinus Pennsylvanica Marsh. ssp. Oregana can be done through several methods, including seed propagation and vegetative propagation.
Seed Propagation
The first step in seed propagation is to collect mature fruits from the tree. Fruits are usually ready to be harvested in late summer or early fall and can be identified by their reddish-brown color.
Once the fruits are collected, they should be cleaned and soaked in water for several days. This will help to soften the fruit and make it easier to remove the seed.
After the seed is removed from the fruit, it should be stored in a cool, dry place until the following spring when it can be planted. Fraxinus Pennsylvanica Marsh. ssp. Oregana seeds require a period of stratification before they can germinate, so they should be placed in a refrigerator for 2-3 months prior to planting.
Seeds can be planted in pots or directly in the ground and should be covered lightly with soil. They should be watered regularly and kept in a warm, sunny location. Germination can take several weeks to several months, depending on the conditions.
Vegetative Propagation
Vegetative propagation involves taking cuttings from an existing Fraxinus Pennsylvanica Marsh. ssp. Oregana tree and encouraging them to root and grow into a new tree.
The best time to take cuttings is in the early spring before the tree has begun to leaf out. Cuttings should be taken from the current year's growth and should be 6-8 inches long with several nodes.
Once the cuttings are taken, the leaves should be removed from the bottom half of the stem. The cuttings can be dipped in rooting hormone to encourage root growth and then planted in a well-draining soil mix. The cuttings should be kept in a warm, humid location and misted regularly to prevent them from drying out.
Rooting can take several weeks to several months, depending on the conditions. Once the cuttings have rooted and begun to grow, they can be transplanted into larger pots or directly into the ground.
Disease and Pest Management for Fraxinus pennsylvanica Marsh. ssp. oregana
Fraxinus pennsylvanica Marsh. ssp. oregana, commonly known as Oregon ash, is a deciduous tree species native to the Pacific Northwest Region of North America. As with most trees, Oregon ash is susceptible to a wide range of diseases and pests that can negatively impact its health. Here are some of the common diseases and pests affecting Oregon ash and how to manage them.
Diseases
One common disease affecting Oregon ash is ash anthracnose, which is caused by the fungus Gloeosporium aridum. It causes brown spots and cankers on leaves, twigs, and branches. Severe infections can cause defoliation, stunted growth, and dieback. To manage ash anthracnose, prune infected branches and improve tree vigor through proper fertilization and watering. Fungicide sprays can also be used in severe cases.
Another disease that can affect Oregon ash is ash yellows, a viral disease spread by insect vectors such as leafhoppers and planthoppers. Symptoms include yellowing of leaves, stunted growth, and twig dieback. There is no cure for ash yellows, so infected trees should be removed to prevent the spread of the disease.
Oregon ash can also be affected by root rot, which is caused by soilborne pathogens such as Armillaria mellea and Phytophthora species. Symptoms include wilting, yellowing leaves, and dieback. To manage root rot, improve soil drainage and avoid overwatering. Fungicide treatments can also be used in severe cases.
Pests
Oregon ash is susceptible to a variety of pests, including the emerald ash borer (EAB) and the ash whitefly. EAB is an invasive species that feeds on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients. Symptoms of EAB infestation include canopy thinning, bark splitting, and D-shaped exit holes. To manage EAB, insecticide treatments can be used, but early detection is crucial for effective control.
The ash whitefly is another insect pest that can infest Oregon ash. It feeds on the undersides of leaves, causing yellowing and stunting of growth. Heavy infestations can cause defoliation and dieback. To manage ash whitefly, introduce natural predators like lacewings or ladybugs or use insecticidal soaps. Neem oil can also be used to control whiteflies.
In conclusion, Oregon ash is prone to diseases and pests that can negatively impact its health and reduce its aesthetic and economic value. Proper care and management practices, including pruning, fertilization, and pest management strategies, can help prevent and control these issues.
