The hazelnut (often called a filbert) is popular among home gardeners and commercial growers for its delicious, nutritious nuts. Understanding its growth rate is essential for setting expectations regarding harvest time and final size. Compared to many nut trees that require a decade or more to become productive, the hazelnut offers a comparatively faster track to yield. This overview details the typical growth trajectory, the environmental conditions that influence its speed, and the different forms the plant can take.
Average Annual Growth Trajectory
Hazelnut trees are moderately fast-growing compared to other nut species. The growth rate changes significantly after the first year. During the initial establishment phase (the first year or two), the plant directs most energy into developing a robust root system. Above-ground height gain may appear slow during this time, as the tree prioritizes stability over vertical expansion.
Once established, a healthy hazelnut enters a rapid vegetative growth phase, adding approximately 1 to 3 feet of height annually, depending on the variety and local conditions. This vigorous growth quickly develops the branching structure necessary for future nut production. After the tree begins bearing a substantial crop (typically around year five), the vertical growth rate slows as the plant diverts energy into producing nuts instead of new wood.
Environmental Factors Influencing Growth Speed
The baseline growth rate is modulated by the specific conditions of the planting site. Sunlight exposure is a major factor; hazelnut trees require at least six to eight hours of direct sunlight daily for vigorous growth and optimal nut production. Trees planted in partial shade will grow slower, and nut yield will be reduced.
Soil composition and drainage are equally important, as hazelnuts are susceptible to root rot if they sit in standing water. They thrive in well-drained, loamy soils with a slightly acidic to neutral pH, ideally between 6.0 and 7.5. Maintaining the soil within this optimal range supports faster, healthier growth.
Consistent water availability is necessary, especially during the first few years of establishment, to support root development. While mature trees are drought-tolerant, young plants need about one to two inches of water per week until their deep fibrous root systems are fully developed. A temperate climate also requires sufficient winter chill hours (800 to 1,200 hours below 45°F) for buds to break dormancy and flower properly.
Strong, persistent winds can slow the growth rate by drying out the plant and causing physical damage, particularly when combined with high summer heat. Providing wind shelter, especially for young trees, helps ensure energy is used for growth rather than recovery. Applying a balanced fertilizer, particularly nitrogen, can boost growth in the first few years if the soil is poor.
Timeline from Planting to Full Production
Achieving a sustainable harvest requires patience, following a predictable timeline. The first two years focus primarily on root establishment, with minimal visible growth. By years three to four, the tree typically begins to flower and may produce its first small, sporadic yields. This initial harvest is often referred to as a nuisance crop because it is too small to be commercially viable.
The tree transitions into the commercial production phase around years five to eight, with yields increasing significantly annually. During this period, the plant develops a mature canopy capable of supporting a substantial nut load. Maximum yield potential and full maturity are reached around year ten and beyond, when the tree’s energy is consistently directed toward nut production.
The ultimate size depends on the variety and pruning, but a mature hazelnut can reach 10 to 20 feet in height with a similar spread. With proper management (pruning, fertilization, and disease control), a hazelnut orchard can remain highly productive for 40 to 50 years.
Growth Habits of Common Hazelnut Species
The ultimate shape and size of a hazelnut plant are dictated by its genetics, specifically whether it is a European or American species. The European hazelnut (Corylus avellana) is the primary source for commercial production worldwide due to its large nuts. This species is typically trained as a single-trunk tree, although it naturally forms a multi-stemmed shrub.
European varieties often grow taller, reaching 15 to 20 feet or more when trained. In contrast, the American hazelnut (Corylus americana) is a smaller, hardier species native to North America. The American type naturally grows as a dense, multi-stemmed shrub that produces suckers from the base.
This multi-stemmed shrub form is more compact, generally reaching a maximum height of 8 to 16 feet. American hazelnuts are favored for their cold hardiness and disease resistance, making them suitable for challenging climates. Hybrid varieties, which combine the cold tolerance of the American species with the larger nut size of the European type, exhibit intermediate growth habits.