Hazelnut trees, often called filberts, are a popular choice for home orchards, valued for their edible nuts and relative ease of care. The successful establishment of these deciduous trees depends significantly on planting them at the correct time. Choosing the right planting window ensures the young tree can dedicate its limited energy to root development rather than supporting new foliage growth, which is crucial for long-term survival and productivity.
The Optimal Planting Window (Dormancy)
The best time to plant hazelnut trees is during their dormant period, which is the time of year when the tree is not actively growing. This critical window occurs twice annually: late fall, after the leaves have dropped, and early spring, just before the buds begin to swell. Planting during dormancy minimizes the severe physiological stress known as transplant shock, which is caused by the sudden disruption of the root system.
When the tree is dormant, its energy reserves are stored in the roots and trunk rather than being actively used for photosynthesis and leaf maintenance. This allows the newly planted roots to establish contact with the soil and begin growing before the demands of spring foliage appear. Bare-root hazelnut stock, which is sold without soil around the roots, must be planted exclusively during this dormant phase to ensure survival.
Containerized hazelnut trees offer slightly more flexibility but still benefit from a dormant planting. Planting a containerized tree in late spring or summer forces it to expend energy on both root establishment and supporting a full canopy of leaves, making it susceptible to drought and heat stress. Planting in late fall or early spring capitalizes on the tree’s natural resting cycle, giving it a head start on root development when soil temperatures are cool.
Adjusting Planting Time by Climate Zone
While the dormant period provides the general window, the specific timing should be adjusted based on the local climate and hardiness zone. In warmer climates, typically found in USDA Zones 7 through 9, fall planting is often preferred. The mild winters in these regions allow the roots to actively grow and establish themselves throughout the cool season without the threat of a deep, sustained freeze.
Planting in the fall in these zones means the tree is well-anchored and has a functioning root system ready to support vigorous top growth when spring arrives. Conversely, in colder, northern regions, such as USDA Zones 4 through 6, a late winter or early spring planting is generally safer. Planting too late in the fall in these areas risks the young tree being killed by deep frost before its roots can properly establish in the frozen ground.
Regardless of the season, planting should only occur when the soil is workable and not waterlogged. Attempting to plant in muddy soil leads to poor root-to-soil contact and compacts the planting hole, which is detrimental to the hazelnut’s long-term health. Planting into frozen ground must be avoided until the soil has thawed and drained sufficiently.
Site Selection and Soil Preparation
The success of a hazelnut tree is not solely dependent on planting time but also on the environment it is placed into. Hazelnut trees require a location that receives full sun, meaning a minimum of six to eight hours of direct sunlight daily. Adequate sun exposure is necessary for robust growth and the initiation of flower buds that will eventually become nuts.
Creating a well-drained environment is essential, as hazelnut roots are intolerant of standing water or “wet feet.” While they can tolerate a range of soil types, including sandy and clay loams, the location must be free of chronic waterlogging, which often leads to root rot. If the site has heavy clay, amending the soil with organic matter is necessary to improve aeration and drainage.
A soil test should be conducted months before planting to determine the existing pH and nutrient levels. Hazelnut trees thrive in slightly acidic to neutral soil, with an optimal pH range of 5.5 to 7.5. If the soil test reveals a highly acidic pH (below 5.5), agricultural lime can be incorporated into the soil in the weeks leading up to the intended planting date. This preparation ensures the tree has the best possible conditions for quick establishment.