Corylus

Description

Corylus is a genus of trees and shrubs that belong to the Betulaceae family. Commonly known as hazels, these plants are native to the temperate regions of the Northern Hemisphere. The genus consists of around 20 species, including the popular Corylus avellana or common hazel, which is widely cultivated for its nuts. The genus name Corylus is derived from the Greek word “korys,” which means helmet, referring to the husk surrounding the nut.

Taxonomic Information

Appearance

Corylus plants can grow up to 20 meters tall, but most species are shrubs or small trees that reach a height of 3 to 6 meters. The leaves are simple, alternate, and deciduous, with serrated edges. The flowers appear in early spring, before the leaves, in clusters of male catkins and smaller female flowers. The fruit is a nut surrounded by a leafy or spiny husk. The nut is edible and has a hard, woody shell.

Care Guide

Corylus plants are easy to care for and can thrive in a variety of conditions. Here are some tips on how to care for your hazel:

• Water: Hazel plants prefer moist but well-drained soil. Water regularly during the growing season, but avoid overwatering.
• Fertilization: Use a balanced fertilizer in the spring to promote healthy growth. Avoid overfertilizing, as this can lead to excessive foliage and poor nut production.
• Soil: Hazels prefer loamy, slightly acidic soil. Add organic matter to improve soil quality.
• Sunlight: Hazels prefer full sun or partial shade. Avoid planting in extremely hot or dry areas.
• Hardiness Zones: Hazels are hardy in USDA zones 4-8. Some species may be more cold-tolerant than others.

Common Pests & Diseases

Like all plants, hazels are susceptible to pests and diseases. Here are some common problems to watch out for:

• Aphids: These small insects can cause leaf curl and stunted growth. Use insecticidal soap to control infestations.
• Spider mites: These tiny pests can cause yellowing and wilting of leaves. Use insecticidal soap or neem oil to control infestations.
• Leaf spot: This fungal disease can cause brown spots and premature leaf drop. Remove infected leaves and avoid overhead watering.
• Bacterial blight: This disease can cause wilting and dieback of branches. Remove infected branches and avoid overhead watering.

Habitat

Corylus plants are native to the temperate regions of the Northern Hemisphere, including Europe, Asia, and North America. They can be found in a variety of habitats, including woodlands, hedgerows, and riverbanks. Some species are adapted to dry, rocky soils, while others prefer moist, well-drained soils.

Question and Answer

Q: Are hazel nuts edible?
A: Yes, hazel nuts are edible and are commonly used in cooking and baking.

Q: How long does it take for hazel trees to bear fruit?
A: Hazel trees typically begin to bear fruit after 3-4 years, with peak production occurring at around 8-10 years.

Q: Can hazel plants be grown in containers?
A: Yes, hazel plants can be grown in containers. Choose a large container with good drainage and use a well-draining potting mix.

Q: Are hazel plants deer-resistant?
A: Some hazel species, such as the American hazel (Corylus americana), are deer-resistant. However, others may be more attractive to deer.

Related Plants

• Betula (birch)
• Alnus (alder)
• Carpinus (hornbeam)
• Ostrya (hop-hornbeam)

References

• Dirr, M. A. (2009). Manual of woody landscape plants: Their identification, ornamental characteristics, culture, propagation and uses. Stipes Publishing.
• Missouri Botanical Garden. (n.d.). Corylus. Retrieved from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=280186&isprofile=0&
• RHS. (n.d.). Corylus. Retrieved from https://www.rhs.org.uk/plants/search-results?form-mode=false&query=Corylus