Overview of Cornus Sericea
Cornus sericea, commonly known as Red Osier Dogwood, is a deciduous shrub that belongs to the Cornaceae family. This plant is native to North America and can be found in various regions such as Alaska, Canada, and the northernmost parts of the United States.
General Appearance
Red Osier Dogwood can grow up to 3-6 feet. It has a spreading habit that can reach up to 10 feet. The leaves are oval-shaped, pointed, and 2-5 inches long. During autumn, the leaves change from green to shades of red or purple. The bark is a bright red color that provides an excellent contrast to the green foliage.
Common Names
The plant has several common names, including Red Osier Dogwood, Western Dogwood, American Dogwood, and Red Willow.
Uses
Cornus sericea is a popular ornamental shrub due to its vibrant bark color and its tolerance for a wide range of soil moisture conditions. The plant can grow in wet areas, making it an ideal choice for rain gardens or along streams and ponds. The bark contains medicinal properties that can be used to treat various ailments such as fever, cold, and diarrhea. In addition, the twigs can be used in basket making and crafts.
Growth Conditions of Cornus sericea
Light Requirements: Cornus sericea commonly known as red osier dogwood requires full sun to partial shade for its proper growth. It thrives well in areas that receive six hours of sunlight per day. When grown in shaded areas, the plant tends to have fewer flowers and fruits compared to those grown in full sun.
Temperature Requirements: Cornus sericea can survive in a wide range of temperatures but thrives best in cool climates. It can grow in USDA hardiness zones 2 to 8. During the growing period, the ideal temperature range is between 18°C to 24°C (65°F to 75°F). The plant can tolerate frost, but it is vulnerable to heat stress.
Soil Requirements: Cornus sericea grows well in fertile, acidic soils that have good drainage. It can also grow in loamy soils with a pH range between 5.0 to 7.0. The plant prefers moist soils and can tolerate occasional flooding. It is not suited for clayey or alkaline soils.
Water Requirements: Cornus sericea has moderate water requirements. During the growing season, the plant needs regular watering to keep the soil moist. However, it is essential not to overwater the plant as it can lead to root rot. During the dormant season, the plant can withstand drought and requires minimal watering.
Fertilizer Requirements: Cornus sericea does not need much fertilization. Applying a slow-release fertilizer during early spring can help provide the plant with necessary nutrients. However, excessive use of fertilizers can cause the plant to grow too fast, leading to weak branches with reduced ability to resist pests and diseases.
Cultivation Methods
Cornus sericea thrives in areas with moist, well-drained soils but can tolerate a wide range of soil types, including clay soils. It grows best in full sun but can also tolerate partial shade. For best results, plant Cornus sericea in the spring or fall.
When planting, dig a hole that is twice the diameter and depth of the root ball. Gently loosen the roots before placing the shrub in the hole. Backfill with soil and water thoroughly.
Watering Needs
Cornus sericea prefers consistent moisture, especially during its first growing season. Water deeply once a week, or more often during periods of drought or high heat. Avoid overwatering, as this can lead to root rot.
Fertilization
Cornus sericea benefits from a balanced fertilizer application in the spring. Apply a slow-release fertilizer according to the label instructions, and water thoroughly after application. Avoid over-fertilizing, as this can lead to excessive growth and weak stems.
Pruning
To maintain a bushy and healthy appearance, prune Cornus sericea annually in the late winter or early spring before new growth appears. Remove dead or damaged branches and cut back up to one-third of the oldest branches to promote new growth. Take care not to remove too much of the plant, or it may lose its natural shape.
Propagation of Cornus sericea
Cornus sericea, commonly known as redtwig dogwood, can be propagated through various methods such as seeds, stem cuttings, and division.
Propagation by Seeds
To propagate through seeds, collect mature fruits during late summer and remove the seeds by washing and cleaning them. Store the cleaned seeds in a cool and dry place until spring. In the spring, sow the seeds in well-draining soil in a shaded area. Keep the soil moist, and the seeds should germinate within a few weeks.
Propagation by Stem Cuttings
Propagation of Cornus sericea by stem cuttings can be done during late spring or early summer. Select healthy vegetative shoots that are approximately 6 inches in length with at least two nodes. Remove the lower leaves and stem, leaving only two to three leaves at the tip. Dip the cuttings in rooting hormone and insert them into a pot filled with well-draining soil. Keep the soil moist, and the cuttings should root within four to six weeks.
Propagation by Division
Propagation by division can be done during the dormant season. Dig up the plant and divide the root system into several sections, ensuring that each section has its shoot. Replant the divisions in well-draining soil and keep the soil moist until the new plants are established.
According to the propagation method used, the young plants may take several weeks to months to establish and grow into mature plants. However, with proper care and management, Cornus sericea can be propagated successfully.
Disease Management:
Cornus sericea, commonly known as red twig or red osier dogwood, is susceptible to some disease issues that can affect its growth and appearance. Some common diseases that can affect the plant include:
- Septoria leaf spot: It is a fungal disease commonly observed in humid conditions. To manage it, remove and destroy the infected plant tissue and avoid overhead watering that can spread the spores. Fungicides containing copper or chlorothalonil can also help in controlling the disease.
- Leaf blight: Caused by the fungus Apiosporina morbosa, is another disease that can cause severe defoliation if not treated. Prune the infected branches and dispose of them properly, sanitize cutting tools, and avoid wetting the leaves while watering.
- Powdery mildew: A fungal disease that causes a powdery white covering on the leaves, twigs, and flowers. Application of fungicides containing potassium bicarbonate, neem oil, or sulfur can manage the disease effectively.
Pest Management:
Cornus sericea is relatively resistant to pests but may suffer from attack by a few common pests like:
- Aphids: These insects suck sap from the leaves and twigs of the plant. You can spray the plant with a stream of water to dislodge the aphids or apply insecticidal soaps or oils that desiccate and kill the pests.
- Lecanium scale: A scale insect that feeds on plant sap, leading to twig dieback and stunted growth. Use dormant oil sprays to smother the insects or apply systemic pesticides to control the pests.
- Japanese beetles: These beetles chew on the leaves and flowers, causing extensive damage to the plant. Handpicking the beetles and dropping them into soapy water or applying neem oil, pyrethrin, or spinosad can help control the beetles.
