To care for hazelnuts, make sure that the soil around them is moist and has adequate drainage. Add compost or another organic substance to the soil to make it more acidic, as this creates better conditions for hazelnut bushes. Once you plant a hazelnut bush, remember to water it regularly for the first two years of its growth. After that period of time, water the plant one or two times per month.
Place about 3 to 4 inches of bark mulch around the base of the tree to keep the soil moist and prevent weed germination in the area. It is not required to fertilize hazelnut trees if there are no problems, but if the amount of nuts the tree produces decreases, add some 10-10-10 balanced fertilizer to the soil in the spring. There are two types of hazelnut trees: male and female. Unless there is a tree of an opposite sex growing close by, a hazelnut does not produce nuts, so plant several trees together.
Harvest hazelnuts in September and October. The leaves and burrs on the tree should start turning brown at that time. The nuts are not completely ripe then, but waiting longer can result in wild animals eating all the nuts. It is better to prune hazelnut bushes in the fall after all the leaves fall off the them; pruning in the spring or summer is not advised.