Hazelnut trees (Corylus spp.) are highly valued for their nutritious and flavorful nuts, making them a popular choice for home orchards and commercial cultivation alike. Beyond their edible benefits, these versatile trees also enhance landscapes with their attractive foliage, unique catkins, and multi-stemmed growth habit. Additionally, hazelnut trees play a crucial role in supporting wildlife, providing food and shelter for various bird species, small mammals, and beneficial insects.
One of the key advantages of growing hazelnuts is their adaptability. They thrive in a range of climates and soil conditions, making them a suitable option for many gardeners. With proper care, hazelnut trees can produce abundant harvests while adding beauty and ecological value to your outdoor space.
This guide will walk you through everything you need to know about successfully growing and maintaining hazelnut trees, from planting and pruning to pest management and harvesting.
Understanding Hazelnut Trees
Hazelnut trees (genus Corylus) are widely grown for their delicious, nutrient-rich nuts, commonly known as filberts or cobnuts. These trees are deciduous and can range from small shrubs to medium-sized trees, depending on the species. They are highly valued not only for nut production but also for their role in agroforestry, wildlife habitat, and erosion control.
Types of Hazelnut Trees
There are several species of hazelnut trees, but the most commonly cultivated ones include:
American Hazelnut (Corylus americana)
Native to North America, the American hazelnut is a hardy and adaptable species found in woodlands, thickets, and along riverbanks. It grows as a multi-stemmed shrub, typically reaching heights of 10-15 feet. This species is particularly prized for its resistance to Eastern Filbert Blight (EFB), a fungal disease that affects many hazelnut trees. The nuts are smaller than those of the European variety but have a rich, sweet flavor, making them popular among wildlife and for homegrown production.
European Hazelnut (Corylus avellana)
The European hazelnut is the most widely cultivated species for commercial nut production, particularly in Turkey, Italy, and the Pacific Northwest of the United States. It grows as a small tree or large shrub, reaching 12-20 feet tall, and is known for its high nut yield and superior nut quality. However, it is more susceptible to diseases like Eastern Filbert Blight and bacterial canker, requiring careful management in humid regions. Many well-known hazelnut cultivars, such as ‘Barcelona’ and ‘Ennis’, originate from this species.
Hybrid Hazelnuts
Hybrid hazelnuts are the result of crossbreeding American and European hazelnut species to combine the best traits of both. These hybrids are developed to improve disease resistance (especially against EFB), cold hardiness, and nut productivity. They are ideal for growers in regions where European hazelnuts might struggle due to climate or disease pressures. Many hybrid varieties are grown in the Midwest and Northeast U.S., where they contribute to sustainable agriculture and hazelnut farming.
Ideal Climate and Hardiness Zones
Hazelnut trees thrive in USDA hardiness zones 4-9, though suitability depends on the species:
- American hazelnuts can tolerate colder temperatures and thrive in zones 4-9.
- European hazelnuts prefer milder conditions and do best in zones 6-9, struggling in areas with extreme cold.
- Hybrid hazelnuts offer a broader range, often suitable for zones 4-8, depending on the specific cultivar.
These trees prefer temperate climates with moderate rainfall and well-defined seasons. They grow best in well-drained, loamy soils with a pH between 5.5 and 7.5. While hazelnuts require a certain number of chilling hours in winter for optimal nut production, they are also sensitive to late spring frosts, which can damage flowers and reduce yield.
Planting Hazelnut Trees
Planting hazelnut trees correctly is essential for their long-term health, productivity, and resistance to environmental stressors. Proper site selection, soil preparation, and planting techniques ensure that the trees establish strong root systems and thrive in their environment.
Choosing the Right Location
Hazelnut trees require a carefully chosen location to maximize their growth potential and nut yield.
Sunlight is a crucial factor, as hazelnut trees need at least six hours of direct sunlight per day. Insufficient sunlight can lead to reduced flowering and lower nut production. A location with full sun exposure throughout the day is ideal.
Soil requirements are another important consideration. Hazelnuts prefer well-drained, loamy soil with a pH between 5.5 and 7.5. Heavy clay soils that retain water for long periods can cause root rot, while excessively sandy soils may require additional organic matter to retain moisture and nutrients. If the soil is compacted, amending it with organic compost can improve drainage and aeration.
Spacing between trees is essential for proper airflow, disease prevention, and optimal growth. Hazelnut trees should be planted 10 to 15 feet apart to allow for full canopy development and healthy root expansion. If planting in rows for commercial production or windbreaks, maintaining a spacing of 15 feet between rows is recommended.
Best Time to Plant
The best time to plant hazelnut trees is in the fall or early spring while the tree is dormant. Fall planting allows the roots to establish before winter, leading to a stronger start in spring. However, in regions with harsh winters, early spring planting may be preferable to prevent frost damage to young roots. The goal is to give the tree time to develop a strong root system before the active growing season begins.
How to Plant a Hazelnut Tree
Proper planting techniques ensure that the tree adapts well to its new environment and grows vigorously. Follow these step-by-step instructions to plant a hazelnut tree correctly:
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Dig the planting hole – Dig a hole that is twice as wide and as deep as the root ball. This allows the roots to spread easily and prevents compaction.
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Amend the soil – Mix organic compost into the soil before planting to enhance fertility and improve drainage. A well-amended soil mixture promotes strong root development.
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Position the tree – Place the tree in the hole, making sure that the root collar (where the roots meet the trunk) is level with the ground. Avoid planting too deep, as this can lead to rot, and avoid planting too shallow, which can cause roots to dry out.
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Backfill the hole – Fill the hole with soil, gently tamping it down as you go to eliminate air pockets. Air pockets can cause root desiccation and hinder establishment.
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Water thoroughly – After planting, water the tree deeply to help settle the soil around the roots. Regular deep watering in the first few weeks encourages strong root growth.
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Apply mulch – Spread a 2-3 inch layer of mulch around the base of the tree, leaving a few inches of space around the trunk. Mulch helps retain moisture, regulate soil temperature, and suppress weeds, but direct contact with the trunk should be avoided to prevent rot and pest issues.
Caring for Hazelnut Trees
Proper care ensures that hazelnut trees remain healthy, productive, and resistant to environmental stress. Regular watering, fertilization, pruning, and weed control contribute to their overall growth and nut production.
Watering Requirements
Young hazelnut trees require consistent moisture to establish a strong root system. Deep watering once a week is recommended, especially during dry periods, to encourage deep root development. The soil should remain moist but not waterlogged, as excessive moisture can lead to root rot.
Mature trees become more drought-tolerant and require less frequent watering. However, during extended dry spells, occasional deep watering helps maintain optimal growth and improves nut yield. A layer of mulch around the base of the tree aids in moisture retention and prevents soil from drying out too quickly.
Fertilizing Hazelnut Trees
Applying fertilizer at the right time ensures healthy growth and nut production. A balanced fertilizer, such as a 10-10-10 NPK blend, should be applied in early spring as new growth begins. This provides essential nutrients, including nitrogen for leaf growth, phosphorus for root development, and potassium for overall tree health.
Excessive nitrogen should be avoided, as it encourages excessive foliage growth at the expense of nut production. A soil test can help determine the specific nutrient needs of the tree, ensuring that fertilization is tailored to the growing conditions.
Pruning and Shaping
Pruning is essential for maintaining the structure of the tree, improving airflow, and reducing the risk of disease. The best time to prune hazelnut trees is in late winter or early spring before new growth starts.
Dead, diseased, or crossing branches should be removed to prevent competition for resources and improve the tree’s overall health. Additionally, maintaining an open center shape allows for better sunlight penetration, which enhances nut development and minimizes fungal issues caused by excessive moisture.
Mulching and Weed Control
Mulching helps retain soil moisture, regulate temperature, and suppress weed growth. A 2-3 inch layer of organic mulch, such as wood chips or straw, should be applied around the base of the tree. However, mulch should be kept at least 2 inches away from the trunk to prevent moisture buildup, which can lead to rot or attract pests.
Weeds compete with hazelnut trees for nutrients and water, so regular removal is necessary. Hand-pulling weeds or using mulch as a natural weed barrier helps reduce competition without disturbing the tree’s roots. In larger orchards, controlled cultivation or selective herbicides may be used to manage weed growth effectively.
Growth Rate of Hazelnut Trees
Hazelnut trees are known for their relatively fast growth and early nut production compared to other nut-bearing trees. Their growth rate is influenced by various factors, including species, soil conditions, climate, and overall care.
How Fast Do Hazelnut Trees Grow?
Hazelnut trees are considered moderate to fast growers, typically increasing in height by 13 to 24 inches per year under optimal conditions. This steady growth allows them to establish quickly and reach a productive stage faster than many other nut trees. Growth rates can vary depending on the specific species, with American hazelnuts (Corylus americana) often growing slightly faster than European hazelnuts (Corylus avellana), particularly in colder climates where they are more adaptable.
Factors Affecting Growth Rate
Several key factors influence how quickly a hazelnut tree grows and develops into a productive nut-bearing tree.
Soil fertility plays a crucial role in the tree’s development. Rich, well-drained, loamy soil with ample organic matter promotes faster growth by providing essential nutrients. If the soil is poor or compacted, growth may slow down significantly.
Watering practices also impact the growth rate. Young trees require consistent moisture during their establishment phase, especially in dry periods. While mature hazelnut trees are more drought-tolerant, occasional deep watering during prolonged dry spells helps sustain strong growth and improves nut production.
Pruning and maintenance encourage a strong structural framework, preventing overcrowding of branches and enhancing air circulation. Proper pruning in the early years directs energy toward healthy, balanced growth and can improve nut yield in the long run.
Sunlight exposure is another critical factor. Hazelnut trees require at least six hours of direct sunlight per day to maximize photosynthesis and promote vigorous growth. Trees planted in shady areas tend to grow slower and produce fewer nuts.
When Do Hazelnut Trees Reach Maturity?
Hazelnut trees typically reach their full height of 10 to 20 feet at maturity, depending on species and growing conditions. Growth slows as the tree approaches its mature size, with more energy directed toward nut production rather than vertical growth.
Nut-bearing begins relatively early compared to other nut trees. Most hazelnut trees start producing within 3 to 5 years after planting, with peak nut production occurring between 7 and 10 years. Once mature, a well-maintained hazelnut tree can continue producing nuts for several decades, making it a valuable addition to home orchards and commercial nut farms alike.
Common Pests and Diseases
Hazelnut trees are susceptible to various pests and diseases that can impact growth, nut production, and overall tree health. Early detection and proper management practices help minimize damage and maintain a healthy orchard.
Pests That Affect Hazelnut Trees
Several insects target hazelnut trees, feeding on leaves, sap, or developing nuts. Effective pest control strategies include monitoring, natural predators, and targeted treatments.
Filbertworm is one of the most destructive pests affecting hazelnuts. The larvae of this moth burrow into developing nuts, causing internal damage and making them unsuitable for consumption. Infested nuts may drop prematurely, reducing yield. Pheromone traps are an effective way to monitor filbertworm activity, and timely insecticide applications can help control infestations.
Aphids are small, sap-sucking insects that cluster on the undersides of leaves and tender shoots. They weaken the tree by draining nutrients, leading to yellowing, curling leaves, and stunted growth. Aphids also produce honeydew, which encourages the growth of sooty mold. Natural predators like ladybugs help keep populations in check, while insecticidal soap or neem oil can be used for severe infestations.
Japanese beetles are known for their ability to defoliate hazelnut trees by feeding on leaves. Their damage weakens the tree and reduces its ability to produce energy for nut development. Hand-picking adult beetles in small orchards is an effective method, while traps or targeted insecticides may be necessary for larger infestations.
Diseases to Watch For
Hazelnut trees are vulnerable to several fungal and bacterial diseases that can cause significant damage if left unchecked. Proper tree care, including good pruning practices and selecting disease-resistant varieties, helps reduce the risk of infection.
Eastern Filbert Blight (EFB) is a serious fungal disease that causes dark sunken cankers on branches, leading to dieback and, in severe cases, tree death. The disease spreads through spores, particularly in wet and humid conditions. The best defense against EFB is planting resistant varieties, such as certain hybrid hazelnuts. If infection occurs, pruning out affected branches and applying fungicidal sprays can help manage the disease.
Bacterial blight primarily affects young hazelnut trees, causing dark, water-soaked lesions on leaves and twigs. As the disease progresses, infected branches may wilt and die. To control bacterial blight, infected plant material should be pruned and destroyed, and copper-based sprays can be applied to prevent further spread. Avoiding overhead watering also helps reduce moisture that promotes bacterial growth.
Powdery mildew is a common fungal disease that appears as a white, powdery coating on leaves, inhibiting photosynthesis and weakening the tree. It thrives in humid conditions and poor air circulation. Improving airflow by pruning dense branches, maintaining proper tree spacing, and applying fungicides when necessary can help control outbreaks.
Harvesting and Storing Hazelnuts
Proper harvesting and storage techniques ensure high-quality hazelnuts with excellent flavor and longevity. Knowing the right time to harvest and how to handle the nuts post-harvest helps maximize their shelf life and usability.
When to Harvest
Hazelnuts typically reach maturity and are ready for harvest in late summer to early fall, depending on the variety and local climate. Unlike some nuts that require manual picking, hazelnuts indicate ripeness by naturally falling from the tree. The husks encasing the nuts begin to dry and turn brown as they mature, signaling that they are ready to drop. Regularly checking beneath the tree during the harvest season ensures that nuts are collected at their peak freshness.
How to Harvest
Harvesting hazelnuts is a simple process since they fall naturally when ripe. Gather the fallen nuts from the ground daily to prevent spoilage or damage from pests. Shaking the branches lightly can help release any remaining mature nuts.
Once collected, hazelnuts must be separated from their husks. The husks are typically loose and can be peeled away easily. After husk removal, the nuts should be spread out in a well-ventilated area to dry for 2-4 weeks. Proper drying is essential to reduce moisture content and prevent mold growth. Placing the nuts in a single layer on screens or trays in a shaded, airy location helps speed up the process. Nuts that rattle inside their shells when shaken are fully dried and ready for storage.
Storing Hazelnuts
After drying, hazelnuts should be stored properly to maintain their flavor and freshness. For short-term storage, keep hazelnuts in a cool, dry place in breathable containers such as mesh bags or paper sacks. If stored at room temperature, they remain fresh for several months.
For long-term preservation, refrigerating or freezing hazelnuts is ideal. Unshelled hazelnuts can last up to a year in the refrigerator and two years in the freezer when placed in airtight containers. Shelled hazelnuts have a shorter shelf life but still stay fresh for several months in cold storage. Before use, hazelnuts should be brought to room temperature to enhance their natural flavor.
Propagating Hazelnut Trees
Hazelnut trees can be propagated through seeds, cuttings, or layering. Each method has its advantages and challenges, with some requiring more time and patience than others. Understanding the propagation process helps ensure successful establishment and growth.
Growing from Seeds
Propagating hazelnut trees from seeds is a long-term approach that requires patience. Since hazelnuts have a hard outer shell and a natural dormancy period, the seeds require cold stratification for 3-4 months to break dormancy and stimulate germination.
To stratify hazelnut seeds, place them in moist sand or peat moss inside a plastic bag and store them in a refrigerator at 33-41°F (1-5°C) for the required duration. After stratification, plant the seeds in well-drained soil in early spring, keeping them moist but not waterlogged.
Although hazelnut seedlings will sprout and grow, they may take several years (5-8 years) to mature into productive trees, and there is no guarantee that they will produce the same quality nuts as the parent tree due to genetic variation. For more predictable results, vegetative propagation methods such as cuttings or layering are preferred.
Propagating from Cuttings
Cuttings offer a faster and more reliable way to propagate hazelnut trees while maintaining the desirable traits of the parent plant. The best time to take semi-hardwood cuttings is in late summer, when the new growth has partially matured but is still flexible.
To propagate using cuttings, follow these steps:
- Select healthy, disease-free branches that are about 6-8 inches long with multiple leaf nodes.
- Remove the lower leaves, leaving a few at the top to support photosynthesis.
- Dip the cut end in rooting hormone to encourage root formation.
- Plant the cutting in a moist, well-draining medium, such as a mix of peat moss and perlite.
- Place the cuttings in a high-humidity environment, such as a greenhouse or under a plastic dome, to prevent moisture loss.
- Keep the soil consistently moist but not waterlogged, and provide indirect light.
Roots typically develop within 6-12 weeks, after which the young plants can be transplanted into larger containers before moving them to their permanent location.
Layering Method
The layering method is a natural and reliable way to propagate hazelnut trees while keeping the new plant connected to the parent tree until it establishes roots. This method is particularly useful for home growers who want to expand their orchard with minimal effort.
To propagate hazelnuts using layering:
- Select a healthy, low-growing branch that is flexible enough to bend to the ground.
- Bend the branch down and bury a portion of it in the soil, leaving the tip exposed.
- Wound the buried section slightly by scraping a small section of bark to encourage rooting.
- Secure the buried section with a stake or rock to keep it in place.
- Keep the soil moist around the buried section to promote root development.
Over time, the buried portion will develop roots within a year. Once a strong root system forms, the new plant can be separated from the parent tree and transplanted to a new location.
Hazelnut Tree Companion Planting
Companion planting involves strategically growing beneficial plants alongside hazelnut trees to improve soil health, deter pests, and enhance pollination. Choosing the right companion plants can help hazelnut trees thrive, while avoiding incompatible plants prevents competition and growth issues.
Best Companion Plants
Some plants contribute to a healthier growing environment for hazelnut trees by improving soil fertility, repelling pests, or attracting beneficial insects.
Nitrogen-fixing plants, such as clover, alfalfa, and vetch, play a crucial role in enriching the soil. These plants form a symbiotic relationship with bacteria in their roots, which convert atmospheric nitrogen into a usable form for nearby plants. Since hazelnut trees benefit from moderate nitrogen levels, interplanting with these legumes naturally enhances soil fertility without excessive fertilizer use.
Herbs like basil, chives, and mint serve as natural pest deterrents. Their strong scents help repel aphids, Japanese beetles, and other common hazelnut pests. Additionally, chives have antifungal properties that can reduce the risk of diseases such as powdery mildew.
Bee-friendly flowers, including lavender, marigold, and echinacea, attract pollinators, which are essential for increased nut production. Although hazelnuts are primarily wind-pollinated, a diverse ecosystem with pollinator-friendly plants promotes biodiversity and overall orchard health. Sunflowers and borage can also serve as trap crops, drawing pests away from hazelnut trees.
Plants to Avoid
Certain plants can negatively impact hazelnut trees by releasing harmful chemicals, competing for resources, or creating unfavorable growing conditions.
Walnut trees (Juglans spp.) should be avoided near hazelnut trees because they produce juglone, a natural chemical that inhibits the growth of many plants, including hazelnuts. The toxic effects of juglone can cause stunted growth, leaf yellowing, and even tree decline in susceptible species. If hazelnuts must be planted near walnut trees, they should be positioned at least 50 feet away to minimize the impact of juglone in the soil.
Dense shrubs and aggressive ground covers that compete for sunlight, water, and nutrients can hinder hazelnut tree growth. Plants with extensive root systems, such as bamboo and certain ornamental grasses, can deplete soil moisture and reduce available nutrients. Tall, bushy shrubs may also block airflow, increasing humidity levels and making hazelnut trees more susceptible to fungal diseases like Eastern Filbert Blight.
Conclusion
Hazelnut trees are a rewarding addition to any garden, providing nutritious nuts and beautiful foliage. With proper planting, care, and maintenance, these trees can thrive for decades. Whether you’re a backyard gardener or a small-scale farmer, following this guide will help you grow healthy, productive hazelnut trees.
