The hazelnut (Corylus avellana and Corylus americana), also known as filbert, is a nut-producing shrub or small tree in the birch family. Hazelnuts are among the easiest nut crops to grow on a homestead, producing well on a manageable shrub that is smaller and easier to harvest than most nut trees. The nuts are rich in oil and protein and are used in confections, baking, and as a nut butter. The American hazelnut is native to the eastern United States, while the European hazelnut is the primary commercial species.
Hazelnuts have been gathered by humans for thousands of years. Archaeological evidence shows that hazelnuts were a staple food of Mesolithic peoples in Europe. The European hazelnut (Corylus avellana) was domesticated in the Mediterranean region and was cultivated by the Romans. The Oregon hazelnut industry was established in the early 20th century and now produces 99 percent of the U.S. commercial hazelnut crop.
The American hazelnut (Corylus americana) was used by Native American peoples and was gathered by early colonists. Breeding programs at Rutgers University and other institutions have developed hybrid varieties that combine the cold hardiness and disease resistance of American hazelnuts with the large nut size of European hazelnuts.
Hazelnut plants grow as multi-stemmed shrubs or single-trunked trees 8 to 20 feet (2.5 to 6 meters) tall. The nuts grow in clusters of 2 to 5 and are enclosed in a leafy husk that extends beyond the nut. The shell is smooth and thin compared to other nut crops. The kernel is round, sweet, and rich in oil.
European hazelnuts are susceptible to eastern filbert blight, a fungal disease that has limited their cultivation in the eastern United States. Hybrid varieties developed for eastern growing conditions offer resistance to this disease. Hazelnuts require cross-pollination from a different variety. The plants are extremely cold-hardy, surviving temperatures to minus 30 degrees Fahrenheit (-34 degrees Celsius).
Hazelnuts are grown for nut production and as a landscape shrub on homesteads. The plants are productive, yielding 5 to 15 pounds (2 to 7 kilograms) per mature shrub. A planting of 4 to 6 shrubs is sufficient for a family's nut supply. The nuts store well in the shell for 6 to 12 months in cool, dry conditions.
Hazelnuts are used for fresh eating, roasting, chocolate confections, and hazelnut butter. The shrub's manageable size and attractive foliage make it suitable for smaller properties. Hazelnuts also produce catkins in late winter, providing early-season pollen for honeybees.