Overview of Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg.
Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. is a species of hawthorn, also known as black hawthorn. It is native to western North America, including the Pacific Northwest, California, and British Columbia. The plant can be found growing in moist forests, riverbanks, and meadows.
General Appearance
Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. is a deciduous shrub or small tree that can grow up to 10 meters tall, though it usually grows around 2 to 5 meters. The plant has a rounded crown and a short trunk, covered in brownish-gray bark. Its leaves are simple, alternate, and have serrated margins. They are 2 to 4 centimeters long and have a glossy dark green color on top, while the underside is more of a paler green.
The plant blooms in late spring or early summer with small, white, or pink flowers, growing in clusters. Its fruits are small, red, or black, and round, with a diameter of around 1 centimeter. They ripen in the fall and provide food for birds, while also being edible for humans.
Uses
Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. has been used for its medicinal properties, mainly for heart-related conditions. Its berries, leaves, and flowers have been used in traditional medicine by various tribes in North America. Modern studies have shown that the plant can help lower blood pressure and cholesterol levels, while also having anti-inflammatory properties.
The plant is also used in landscaping, as it adds ornamental value to gardens and parks due to its attractive foliage, flowers, and fruits. Its dense growth makes it a popular choice for hedges, as it can provide privacy and shelter for wildlife.
In addition, the fruits of Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. are used for making jelly and wine and can also be eaten raw or cooked in pies and other desserts. The plant has also been used for its wood, which is strong and slightly flexible, making it suitable for small crafts and tool handles.
Light Requirements
The Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. plant prefers full sun to partial shade. It can tolerate some shade, but it might not produce as many flowers or fruits as it would if it had more sun exposure.
Temperature Requirements
The Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. plant can handle a wide range of temperatures. It grows well in USDA hardiness zones 6 to 9, which means it can tolerate minimum temperatures of -10 to 25 degrees Fahrenheit. This plant can also withstand high temperatures, but it might require some extra water during heatwaves.
Soil Requirements
The Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. plant prefers well-draining soil that is moist but not overly wet. It can grow in a variety of soil types, including loamy, sandy, and clay soils. However, it prefers slightly acidic to neutral pH levels between 5.5 and 7.5. Adding organic matter to the soil can help with drainage, water retention, and nutrient availability.
Cultivation Methods
Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg., also known as Black Hawthorn, is a deciduous shrub or small tree that can reach up to 20 feet in height and spread. It grows best in USDA hardiness zones 4-8 and prefers full sun to partial shade in well-draining soils that are slightly acidic to neutral.
Planting should be done in the fall or early spring, and the root ball should be placed at or slightly above the soil level. The plant should be watered immediately after planting to establish roots.
Watering Needs
Black Hawthorn requires regular watering during the first growing season to establish roots. After that, it is relatively drought-tolerant and does not require much watering. The plant should be watered deeply but infrequently, allowing the soil to dry partially between waterings.
Fertilization
Fertilization should be done in the early spring before new growth starts. A balanced fertilizer with equal parts of nitrogen, phosphorus, and potassium can be used. The fertilizer should be applied at a rate of 1 pound per inch of trunk diameter, spread evenly around the tree's drip line, and watered in thoroughly.
Pruning
Pruning should be done in the late winter or early spring before new growth starts. The plant should be pruned to maintain the desired shape and size, removing any broken, diseased, or crossing branches. Black Hawthorn has thorns, so gloves should be worn while pruning. It is also important to prune the plant regularly to maintain good airflow and prevent any pest or disease issues.
Propagation of Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg.
Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg., commonly known as black hawthorn or river hawthorn, can be propagated through several methods such as seed propagation, hardwood cuttings, layering, and grafting.
Seed Propagation
The most common propagation method for Crataegus douglasii var. rivularis is seed propagation. Hawthorn seeds have a hard seed coat that needs to be stratified or scarified before planting. Stratification refers to the process of exposing seeds to cold, moist conditions for a period of time to simulate natural winter dormancy. Scarification involves nicking or scratching the seed coat to assist germination. After stratification or scarification, plant the seeds in a well-draining soil mix and keep them in a warm, bright area. Germination can take several weeks or months, so be patient and ensure the soil is consistently moist.
Hardwood Cuttings
Hardwood cuttings can be taken from mature hawthorn trees during the dormant season. Select a healthy branch and cut a 6-8 inch section of wood at a 45-degree angle. Dip the base of the cutting in rooting hormone and plant it in a pot filled with a well-draining soil mix. Keep the pot in a bright, warm area and ensure the soil is consistently moist. After several weeks, the cutting should produce roots and can be planted in a larger pot or directly into the ground.
Layering
Layering involves bending a low-hanging branch of a mature hawthorn tree to the ground and burying it in soil while still attached to the parent plant. The branch should be partially stripped of its bark where it will come in contact with the soil to encourage root growth. After a few months, roots should develop, and the new plant can be cut from the parent and transplanted into a pot or directly into the ground.
Grafting
Grafting is a method of propagation that involves attaching a scion (a small piece of a desired plant) to a rootstock (the root system of a different plant). Hawthorns are typically grafted onto rootstocks of other hawthorn species to ensure disease resistance and vigor. This method requires some knowledge of grafting techniques and is typically done by experienced gardeners.
Disease Management for Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg.
The most common diseases that affect Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. are:
- Cedar rust: This disease causes brown spots on the leaves and stems of the plant. It can be managed by removing infected plant parts and applying fungicides.
- Fire blight: This disease causes blackened stems and leaves, which eventually wilt and die. It can be controlled by pruning infected plant parts and spraying with antibiotics.
- Powdery mildew: This disease causes white powdery spots on the leaves and stems of the plant. It can be managed by removing infected plant parts and applying fungicides.
To prevent these diseases, it is important to keep the plant healthy by providing adequate water and nutrients, avoiding overcrowding, and promoting good air circulation.
Pest Management for Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg.
The most common pests that affect Crataegus douglasii Lindl. var. rivularis (Nutt.) Sarg. are:
- Aphids: These insects feed on the sap of the plant, causing stunted growth and leaf distortion. They can be controlled by spraying the plant with insecticidal soap or neem oil.
- Codling moth: This insect feeds on the fruit of the plant, causing wormy apples. It can be controlled by applying pheromone traps or spraying with insecticides.
- Mites: These insects cause bronzed or yellowed leaves and webbing on the plant. They can be managed by removing infected plant parts and spraying with insecticidal soap or neem oil.
To prevent these pests, it is important to keep the plant healthy by providing adequate water and nutrients, avoiding over-fertilization, and practicing good sanitation measures.
