How to grow hazelnut
Overview
Hazelnut (Corylus avellana) is a deciduous, multi-stemmed shrub or small tree grown for its edible nuts. It is a long-term investment, taking 3–5 years to first harvest and 7–10 years for full production. Requires winter chill and cross-pollination for good yields.
Varieties
- Tonda di Giffoni — Italian variety, high kernel quality, good for home gardens.
- Barcelona — Large, round nuts; vigorous and reliable in temperate climates.
- Whiteheart — Early ripening, good flavour, popular in Australian nurseries.
Soil Preparation
Hazelnut prefers slightly acidic to neutral soil (pH 6.0–7.0) with good drainage. Before planting, incorporate well-rotted manure or compost to improve fertility. Avoid heavy clay; if needed, plant on a mound or add gypsum to improve drainage.
Growing Guide
Plant hazelnuts in full sun with well-drained, fertile soil. Space trees 4–6 m apart for good air flow and light. Dig a hole twice the width of the root ball, backfill with compost, and water in well. Mulch thickly (10–15 cm) with straw or wood chips to keep roots cool and moist. Avoid planting in heavy clay or waterlogged sites.
Sowing
Sow hazelnut seeds in autumn (stratified for 3 months at 4°C) directly into the ground or in pots. Plant 2–3 cm deep, spaced 10–15 cm apart. Germination takes 6–12 weeks. For best results, plant stratified nuts in spring after frost risk passes.
Care
Feed hazelnut in early spring with a balanced slow-release fertiliser (e.g., 10-10-10) and top-dress with compost in autumn. Prune annually in winter to remove suckers and open the canopy for light and airflow. Mulch around the base to retain moisture and suppress weeds.
Companion Planting
Companion plants include comfrey (dynamic accumulator), clover (nitrogen fixer), and yarrow (attracts beneficial insects). Avoid planting near black walnut (juglone toxicity) or in areas with heavy shade from larger trees.
Common Pests & Risks
Aphids can cause leaf curl and sooty mould; control with horticultural oil or insecticidal soap. Nut borers (larvae of the hazelnut weevil) tunnel into nuts; remove and destroy infested nuts. Bacterial blight (Xanthomonas) causes cankers; prune out infected wood in winter.
Harvesting
Harvest hazelnuts when they fall to the ground or the husks turn brown and split. Nuts are ready from late summer to autumn. Pick up fallen nuts promptly to avoid mould and pest damage. Dry nuts in a single layer for 2–3 weeks before storing.
In the Kitchen
Hazelnuts are eaten raw, roasted, or ground into flour. Store in a cool, dry place for up to 6 months. Roast at 180°C for 10–12 minutes to enhance flavour. Use in baking, salads, or as a nut butter.
Troubleshooting
Yellow leaves: often due to poor drainage or overwatering; improve soil drainage. Brown leaf edges: caused by salt burn or drought; water deeply and avoid fertiliser burn. Small or empty nuts: lack of pollination; plant two different varieties for cross-pollination. Cankers on branches: bacterial blight; prune out infected wood and avoid overhead watering. Nut drop before maturity: often from insufficient chill hours; choose a variety suited to your zone.