Overview of Corylus avellana L.
Corylus avellana L. is a deciduous woody plant, commonly known as the European hazelnut or cobnut. It belongs to the family Betulaceae and is native to the temperate regions of Europe and western Asia. The plant is grown for its edible nuts and ornamental purposes. The shrub-like tree can grow up to 12 meters in height, and it has a broad, spreading canopy with a dense arrangement of leaves and branches.
Physical Characteristics of Corylus avellana L.
Corylus avellana L. has a rounded to oval shape with slightly serrated edges. The leaves are alternate, deciduous, roughly as broad as they are long, and have a rough texture on both sides. They can be between 6-12cm in length and are a dark green or blue-green color. The branches are woody, but the new stems are hairy and have a reddish-purple color, while the bark is grey-brown and fissured. The plant blooms in early spring, and the male flowers are in the form of catkins (elongated clusters of flowers) while the female flowers are much smaller and grow individually.
Uses of Corylus avellana L.
The nuts of Corylus avellana L. are harvested for their culinary use and are popular in sweet and savory dishes. They can be eaten raw or roasted and are commonly used in confectionery. The leaves and bark of the plant have been used in traditional medicine for their astringent, diuretic, and anti-inflammatory properties. The plant has also been used for soil stabilization, as wildlife habitat, and as an ornamental plant in gardens and urban areas.
Growth Conditions for Corylus avellana L.
Light: Corylus avellana L. is a shade-tolerant plant and grows best in partial shade to full sun. It can tolerate a range of light conditions, but performs best in areas that receive at least six hours of direct sunlight each day.
Temperature: The ideal temperature range for Corylus avellana L. is between 65-75°F (18-24°C) during the day and 55-65°F (12-18°C) at night. The plant can tolerate temperatures as low as -22°F (-30°C) during the dormant season (winter months) and as high as 86°F (30°C) during the growing season (summer months).
Soil Requirements: Corylus avellana L. grows best in well-drained soils that are rich in organic matter. It can tolerate a range of soil types, including loam, clay, and sand, but prefers soils that are slightly acidic to neutral (pH 5.5-7). The plant does not tolerate water-logged soils, so it is important to ensure adequate drainage.
The soil should also be fertile and nutrient-rich, with a pH between 5.5 and 7.0. It is recommended to amend the soil with compost or other organic matter to improve soil structure and fertility. Additionally, Corylus avellana L. prefers soils that are consistently moist, but not water-logged.
Cultivation of Corylus avellana L.
Corylus avellana L., commonly known as Hazelnut, is a deciduous shrub that requires well-draining, fertile soil to grow. The ideal pH range for the plant is 5.5-7.5, so it is essential to test the soil before planting. The plant requires full sunlight to grow optimally.
Propagation of Corylus avellana L. can be done through seeds or vegetative cuttings. If planting through seeds, sow them in well-draining soil and keep them moist until germination occurs. Vegetative cuttings are usually taken from mature plants during dormancy and rooted in a suitable rooting medium.
Watering Needs
Corylus avellana L. requires regular watering, especially during the growing season. Water the plant whenever the top inch of soil feels dry. Overwatering can lead to root rot, so it is crucial to avoid watering the plant too frequently.
During the dormant season, reduce watering to prevent the plant from becoming too wet during the cold season.
Fertilization
Corylus avellana L. requires regular fertilization to thrive. Use a balanced fertilizer with a 10-10-10 NPK ratio, applied during the growing season. Fertilizer should be applied at the base of the plant and watered in thoroughly to ensure proper absorption.
It is also useful to add organic matter, such as compost or well-rotted manure, to the soil to improve soil fertility and provide essential nutrients.
Pruning
Corylus avellana L. requires pruning to maintain its shape and size. Pruning should be done during the dormant season to avoid stressing the plant. Remove any dead or diseased branches, as well as any crossing branches, rubbing branches, and sucker growth.
Pinching back the tips of new growth can also help to encourage bushier growth and prevent the plant from becoming leggy.
Propagation of Corylus avellana L.
Corylus avellana L., commonly known as the common hazel or filbert, is a deciduous shrub that belongs to the family Betulaceae. The shrub is native to Europe, western Asia, and northern Africa. It can be propagated through various methods depending on the availability of planting materials and the desired number of plants.
Seed propagation
Corylus avellana L. can be propagated through seed, which is the most traditional method of propagation. Seeds are collected in autumn or early winter and stratified for two to three months at about 4°C to break their dormancy. After stratification, the seeds can be sown in spring or autumn in well-drained seedbeds.
The seedlings should be watered regularly until they become established, and then they can be transplanted to their permanent site in the garden. However, seed-propagated plants may take up to five years to bear nuts and may not be true to type.
Cuttings propagation
Corylus avellana L. can also be propagated by cuttings, which involves taking stem cuttings from a mature hazel bush and rooting them. Hardwood cuttings are taken in late autumn or winter and are rooted in a mixture of sand and peat.
The cuttings are treated with rooting hormone to encourage root development and are kept in a cool, shaded place until they have rooted. Once rooted, they can be transplanted to a permanent site in the garden.
Layering propagation
Another propagation method for Corylus avellana L. is layering, which involves encouraging the parent plant to produce roots from a stem that is still attached to the shrub. A low-growing stem is selected, and a groove is made on the stem where it touches the soil. The groove is filled with rooting hormone, and the stem is covered with soil.
The stem will eventually produce roots, and once these roots are large enough, the new plant can be separated from the parent plant and transplanted to a permanent site in the garden. Layering helps to produce a new plant that is identical to the parent plant and can bear nuts in a shorter time than seed-propagated plants.
In summary, Corylus avellana L. can be propagated through seed, cuttings, and layering. Each propagation method has its advantages and disadvantages, and the choice of method depends on the availability of planting materials and the desired number of plants.
Disease and Pest Management for Corylus avellana L.
Corylus avellana L., commonly known as the common hazel tree, is a plant from the Betulaceae family. It is a deciduous shrub that is native to Europe and western Asia but widely cultivated in temperate regions worldwide. Like any other plant, Corylus avellana L. is susceptible to various diseases and pests. However, by identifying the common problems and taking preventive measures and mitigation methods, we can keep our hazel trees healthy and productive.
Common Diseases
Various fungal pathogens can cause diseases in Corylus avellana L., especially when the plant is under environmental stress, such as high humidity, poor air circulation, or inadequate nutrition. Here are some of the most common diseases that might affect the common hazel tree:
- Eastern Filbert Blight: Eastern Filbert Blight is a fatal fungal disease that infects most hazelnut varieties. It causes the stem to develop cankers, which can girdle and kill the stem. It is challenging to control or eradicate, and infected plants must be removed and destroyed. Preventive measures include planting resistant cultivars, pruning out infected twigs, and ensuring adequate nutrition and irrigation.
- Coryneum blight: Coryneum blight, also known as shot hole disease, is caused by a fungus that affects the leaves and twigs of hazel plants. It causes small, circular red-brown spots on leaves, which can eventually lead to defoliation. The infected twigs may develop small, sunken cankers that crack and ooze. This disease can be controlled by pruning out infected twigs, providing adequate nutrition and irrigation, and applying fungicides in the early stages of the infection.
- Powdery Mildew: Powdery mildew is a fungal disease that causes powdery white or gray spots on the leaves, stems, and flowers of hazel plants. It can reduce plant growth, cause defoliation, and lower nut yield and quality. This disease thrives in humid conditions and can be prevented by maintaining good air circulation, avoiding overhead irrigation, and applying a suitable fungicide.
Common Pests
Corylus avellana L. is also vulnerable to several pests that can cause significant damage to the plant's growth and development. Here are some of the most common pests that might affect the common hazel tree:
- Hazelnut Weevil: The hazelnut weevil is a small, reddish-brown beetle that feeds on hazel nuts and damages the kernel. The adult beetles emerge in early summer and lay eggs on the developing nuts. The larvae feed on the nut kernel, causing it to become shriveled and unmarketable. To control this pest, it is advisable to monitor the nuts regularly and remove any infested ones before the larvae emerge.
- Aphids: Aphids are small, soft-bodied insects that suck sap from the leaves and stems of hazel plants. They can cause leaf distortion, stunting, and reduced nut yield. Aphids can be controlled by natural predators, such as ladybugs and lacewings, or by using insecticidal soap or neem oil spray.
- Leafrollers: Leafrollers are small, brown caterpillars that feed on leaves and fruits of hazel plants. They can cause severe defoliation and fruit damage. Handpicking the caterpillars, using pheromone disruptors, or spraying insecticides can help control leafrollers.
Overall, a proactive approach to pest and disease management, including proper pruning, irrigation, nutrition, and sanitation, can help keep Corylus avellana L. trees healthy and productive. In severe infestations or infections, it is advisable to seek the advice of a professional arborist or plant pathologist.
