The Corkscrew Hazel (Corylus avellana ‘Contorta’), also known as Harry Lauder’s Walking Stick, is a deciduous shrub recognized for its distinctive, twisted branches. Its unique form provides significant visual interest, especially in winter when its bare, contorted stems are fully visible. Delicate, pendulous catkins in late winter and early spring further enhance its ornamental appeal. These features make it a popular choice for landscape design, offering architectural structure and a focal point.
Essential Growing Conditions
For the Corkscrew Hazel to thrive and develop its unique characteristics, proper placement and soil preparation are essential.
Sunlight
This plant adapts well to a range of light exposures, flourishing in both full sun and partial shade. While it can tolerate some shade, providing at least six hours of direct sunlight daily generally promotes more robust growth and a denser habit. In regions with intense summer heat, some afternoon shade can help protect the foliage from scorch and reduce plant stress.
Soil
Well-drained soil is important for the Corkscrew Hazel, as its root system is sensitive to excessive moisture. It performs well in various soil types, including sandy, loamy, and clay. The plant prefers neutral to alkaline pH levels but tolerates mildly acidic conditions. Incorporating organic matter before planting improves fertility and drainage, promoting strong root establishment.
Watering
Consistent moisture is beneficial for the Corkscrew Hazel, particularly for newly planted specimens during their first growing season. Regular watering helps develop a deep, healthy root system. Once established, the plant becomes more tolerant of varying moisture levels, but it still benefits from irrigation during prolonged dry periods. Checking the soil moisture by hand, ensuring the top few inches are dry before rewatering, helps prevent both overwatering and underwatering.
Temperature and Hardiness
Corylus avellana ‘Contorta’ is a hardy shrub, typically thriving in USDA Hardiness Zones 4 through 8. This indicates its ability to withstand winter temperatures ranging from approximately -30°C to -1°C (-20°F to 30°F). It performs best in climates that experience distinct seasons, with mild summers and cold winters. While generally resilient, extreme heat can sometimes cause stress, leading to leaf browning or reduced vigor.
Pruning for Form and Health
Pruning maintains the Corkscrew Hazel’s distinctive twisted form and overall health, enhancing its ornamental appeal, especially in winter.
The best time to prune is late winter or early spring, while the plant is dormant and before new growth. This timing allows a clear view of the branch structure and minimizes plant stress. Remove dead, damaged, or crossing branches to improve air circulation and prevent disease.
To maintain its unique contorted habit, remove any straight, non-twisted shoots that may emerge from the base or rootstock. These straight suckers are vigorous and can quickly outgrow and eventually overtake the desirable twisted branches if not removed promptly. If a more significant reduction in size or shaping is needed, it is generally advised to remove no more than one-third of the oldest stems each year over a period of two or three years, rather than a severe, single-session hard prune. This gradual approach helps preserve the plant’s health and its characteristic form.
Common Pests and Diseases
While generally robust, the Corkscrew Hazel can encounter certain pests and diseases. Awareness of these potential issues allows for timely intervention.
Aphids can infest Corkscrew Hazels, appearing as small insects on the undersides of leaves and new shoots. Their feeding distorts foliage and excretes honeydew, which may attract ants. Scale insects are another potential pest, appearing as small, stationary bumps on stems, also producing honeydew and weakening the plant by sucking sap.
Fungal issues like powdery mildew may affect leaves, appearing as a white, powdery coating, particularly in humid conditions. Bacterial blight can also occur, causing brown spots on leaves and lesions on branches. Regular inspection allows for early detection. Addressing these issues typically involves removing affected plant parts, maintaining good air circulation, and, if necessary, applying appropriate organic treatments.
Winter Protection
The Corkscrew Hazel is hardy, but some measures can help it navigate colder months, especially for younger plants or those in exposed locations. These steps primarily focus on protecting the root system and ensuring moisture retention.
Applying a layer of organic mulch, such as wood chips or compost, around the base of the plant in late autumn insulates the soil. This mulch layer regulates soil temperature, protecting roots from extreme cold and preventing frost heave. For container plants, move them to a sheltered location, like against a house wall or in a shed, for additional protection from harsh winter winds and excessive freezing. While established plants tolerate winter conditions well, young trees may benefit from extra care during their first few winters.