Hazelnut tree (Corylus avellana) are deciduous trees that thrive in U.S. Department of Agriculture plant hardiness zones 4 through 9. The trees have a fast growth rate and reach heights of 15 to 40 feet with a spread of 10 to 12 feet. It is multi-trunk tree that is often pruned down to a single trunk.
Hazelnut tree have a distinct flavor and there are many varieties that are roasted or eaten raw. Knowing when to expect a crop is helpful for planning hazelnuts into your culinary experience.
Years to Production
A newly planted hazelnut tree does not start producing a nut crop until the tree becomes established. A first hazelnut crop can be expected within two to five years of planting the tree.
The initial crops are usually small, but as the tree matures, the crops increase in size. A mature hazelnut tree can produce up to 25 pounds of nuts in a single year. Once a tree begins to produce, you can expect a new crop of hazelnuts each year, up to 50 years.
Key to Production
If a hazelnut tree is older than five years and has yet to produce nuts, the tree is likely missing its mate. Hazelnut trees require cross pollination from a different hazelnut cultivar to produce a nut crop.
You must grow two hazelnut trees with strong genetic differences, one as a pollinator and the other as a producer to get a nut crop. These trees need to be within about 65 feet of each other for cross pollination to take place.
Pollination and Fertilization
Pollination and fertilization must also take place for your hazelnut tree to begin producing nuts. While most trees bloom and pollinate during the spring, the hazelnut tree is unusual, as it blooms and pollination occurs during the winter.
Despite the need for a different cultivar for fertilization to occur, hazelnut trees bloom with both male and female flower. The male flowers are elongated and yellow, while the female flowers are small and red. Pollen travels on the breeze during the winter to the female flowers of the nut-producing tree.
The pollen is stored there and the tree remains dormant until the spring, when fertilization occurs, signaling the tree to start producing nuts. Once a tree is established, in its second to fifth year, you will begin to notice hazelnuts forming during May.
While they are still growing on the tree, hazelnuts are green. As the nuts mature, they begin to turn brown. Hazelnuts signify that they are ready for harvest by falling from the tree.
Nuts begin to fall from the tree as early as August but are generally ready for harvest during September and October. Due to its dense canopy and blockage of sunlight, hazelnut trees usually have very little turf grass growing beneath them, making it easier to spot and harvest nuts as they fall to the ground.