Question
I have one hazel nut tree which produced catkins but no nuts. I want to know if it is self pollinating and when to properly prune it to promote production. I do not know the variety. I may want to transplant it this year, when is the appropriate time to do that? Thank you, Beverly McDermott Flushing NY

Answer
  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.
  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 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 should begin to notice hazelnuts forming during May.
  In early spring before leaf out would be the best time to transplant a tree. When you do dig the root ball as large as you can. and the then dig the new hole twice the size of the root ball and fill with good top soil or potting soil. But be advised that this disturbance will set back the nut production until the root system has been established.
 Here is a source for more information on hazelnut growing  http://www.oregonhazelnuts.org/growers-corner/grower-handbook/