The hazelnut, or filbert (Corylus avellana), is a deciduous shrub or small tree cultivated globally for its edible nuts. Pruning is a fundamental horticultural practice used to regulate the size of the canopy and improve the plant’s overall health. This management encourages better light distribution and air movement, directly impacting nut production. A structured approach helps establish a robust framework that supports heavy yields and improves access for maintenance and harvesting.
Timing and Objectives for Pruning Hazelnuts
The optimal time for major structural pruning of hazelnut plants is during the late winter or very early spring, while the plant remains dormant. Pruning during this dormant season minimizes stress and allows the grower to clearly see the complete branch structure. The absence of leaves makes it easier to identify crossing branches and assess canopy density.
A primary objective is maximizing sunlight exposure to the interior wood, which is necessary for flower bud development and nut set. Growers also remove dead, diseased, or damaged wood to maintain sanitary conditions. Shaping the plant and promoting new, productive fruiting wood are goals, as hazelnuts bear nuts primarily on wood grown the previous year.
Training Newly Planted and Young Trees
Establishing the permanent scaffold structure is the most impactful pruning activity in the first few years after planting. Growers generally choose between training the plant as a single-trunk tree (often preferred for commercial orchards) or allowing it to develop into a natural multi-stemmed bush. The single-trunk system, known as a central leader, focuses on developing a strong, upright main stem.
Upon planting, the young whip is typically topped with a heading cut made approximately 28 to 34 inches from the ground to reduce water demand and encourage new shoots. During the first dormant season, the focus shifts to selecting three to five permanent scaffold branches that will form the tree’s framework.
These selected limbs should be evenly spaced vertically and radially around the trunk, maintaining a vertical distance of at least six inches between them. It is important to choose branches that form wide angles with the trunk (45 to 60 degrees), as these angles promote structural strength and minimize splitting under a heavy nut load. If the chosen scaffold branches have grown more than two feet without developing lateral shoots, they should be headed back to stimulate branching and encourage a denser framework.
Maintenance Pruning for Mature Trees
Once the hazelnut tree reaches maturity, pruning shifts from structural establishment to annual maintenance and renewal. The goal is to regulate older, less productive wood and replace it with younger, more vigorous growth that carries the most nut-bearing spurs. Since nuts are borne on one-year-old wood, consistent new growth is necessary for sustained production; the tree should put on at least six to eight inches of new terminal growth annually.
Maintenance involves renewal pruning to remove older, non-productive branches, making space for new growth and maintaining productivity. Most cuts should be thinning cuts, which remove an entire branch back to a larger limb or the main trunk at the branch collar. Thinning cuts are preferred because they open the canopy to sunlight without causing the flush of vigorous, unproductive shoot growth that often follows a heading cut.
Annual maintenance should focus on removing growth that is crossing, rubbing, or growing inward toward the canopy center. Maintaining an open center shape allows maximum light exposure to the lower and interior portions of the tree, which is necessary for nut production. Growers should aim to remove no more than 25 to 30 percent of the living canopy in any single year to prevent excessive stress and yield reduction.
Managing Suckers and Watersprouts
Two distinct types of unwanted, vigorous growth commonly appear on hazelnut plants: suckers and watersprouts. Suckers are shoots that emerge directly from the root crown or root system, often originating from the rootstock rather than the desired cultivar. These growths divert energy from the main canopy and must be removed consistently, especially on young trees where they slow down growth and productivity.
The most effective method for sucker removal is to physically tear or cut them off as close to their point of origin as possible, ideally below the soil line. Cutting suckers at ground level often leaves dormant buds that rapidly regrow, so disrupting the growth point minimizes the likelihood of immediate recurrence. This process needs to be repeated throughout the growing season as suckers are prone to re-emerge.
Watersprouts are rapidly growing, upright shoots that emerge from existing branches within the canopy, often in response to a harsh pruning cut. They cast excessive shade on the lower fruiting wood and should be removed unless intentionally saved to replace an old, declining scaffold branch. Their removal ensures that available light is directed toward the more productive, horizontal fruiting wood.