Hazelnut trees, known for the edible nuts they produce, are towering shade trees that reach up to 45 feet tall. The leaf canopy spreads as much as 30 feet. New trees may take up to four years before they produce a consistent nut crop, but once the hazelnuts start appearing, fresh nuts will be abundant every year. Keep hazelnut trees healthy with proper care and pruning techniques.
Test the soil pH where the hazelnut tree is planted. The tree prefers soil with a pH of 6.0 to 7.0. Home test kits are available to make it easy to test the soil's balance. Add lime fertiliser to the soil to raise the pH or sulphur to lower it, per soil test recommendations.
Keep hazelnuts planted in rich soil that drains well, in an area that offers wind protection.
Apply a thin coat of water and white latex, mixed in equal parts, to the south side of the trunk, using a paintbrush, at the beginning of the summer. The thin coat of paint will help protect the tree from sunburn. Apply paint only to young hazelnut trees that haven't started producing nuts.
Place a 2-inch layer of mulch in a 3-foot ring around the tree to hold in soil moisture. The mulch should be placed 3 inches away from base of the trunk in a large circle around the tree; do not allow mulch to directly touch the tree trunk. Straw, plastic, bark and wood chips may all be used for hazelnut mulches.
Prune hazelnut trees once every five years or so, in late fall or winter. Cut away broken, downward-facing and crisscrossing branches, using sharp hand shears. Make cuts at a slight angle, just above leaf nodes.
Thin branches near the top of the tree after it's 10 to 15 years old, to allow more light to reach the rest of the tree.
Harvest hazelnuts, using a hand rake, when they start to fall from the tree in February and March.
Fruit tree borers may bore tunnels into the tree, weakening the stems and trunk. Look for the sawdust-like material they leave behind around the fork of the tree. Scrape the sawdust away and flood the tiny holes with water to get rid of borers. Apply chemical pesticides if needed to completely eliminate borer infestation.