El hazel (Hazelnut corylus) is a fruit-bearing shrub of notable ornamental and productive value, ideal for both domestic gardens and regular plantations, thanks to its adaptability to different climates and soil types. Its cultivation is as interesting for the beauty of its flowers and foliage as for the production of the coveted hazelnuts, fruits rich in nutrients y healthy oilsBelow you will find a comprehensive guide on the essential care of hazelnuts to ensure their proper development, maximum productivity and resistance to pests and diseases.
General characteristics of the hazelnut (Hazelnut corylus)
- Common name: Hazel
- Scientific name: Hazelnut corylus
- Family: Betulaceae
- Origin: Mainly the Eurasian region, with a historical presence in temperate zones of Asia Minor and Europe.
- Type: Deciduous shrub, occasionally small tree.
- Level: Between 2 and 7 meters, and can exceed this size in optimal conditions.
- Sheets: Large, rounded, with a double-toothed edge and coloring that turns yellow before falling.
- Flowers: Male flowers in yellowish, hanging catkins; female flowers in small reddish buds. Flowers bloom in late winter or early spring, before the leaves emerge.
- Fruit: Hazelnut, usually grouped in clusters, surrounded by a green involucre that dries when ripe.
- Longevity: It is a very long-lived plant, with specimens that have been around for centuries in traditional plantations.
The gender Corylus It includes more than fifteen species that grow well in temperate regions of the northern hemisphere, being Hazelnut corylus The most cultivated for the quality of its fruit and its adaptability. This species is used both in the formation of groups, hedges or as an isolated specimen in gardens, and its ornamental varieties are also appreciated, such as the pendulous hazel (pendulum) and the golden-leaved hazel (aura).
Ideal location and climatic conditions for hazelnuts
La location The care of the hazelnut tree is essential for its development. Despite being a very hardy and adaptable plant, for vigorous growth and abundant fruiting, it's advisable to follow these tips:
- Light: It prefers sunny locations, although it also thrives in semi-shade. In very hot areas, light protection from intense sun helps prevent water stress.
- Space: As the hazel tree can reach up to 7 meters in height and expand considerably thanks to its basal shoots or suckers, it is advisable to plant it where it has enough space, away from other competitive trees or structures that limit its development.
- Climate: Best suited to temperate climates, with mild winters and moderate summers. It tolerates frost, but extreme low temperatures can affect sprouting and fruit production.
- Humidity: An environment with moderately high relative humidity favors development and pollination. Gentle winds are beneficial, as they carry pollen, but strong winds or persistent fog can impair flowering and fruit set.
Avoid placing hazelnut trees in areas where water accumulates or in waterlogged soils, as they are susceptible to root suffocation and diseases associated with excess moisture.
Soil and planting requirements
- Substratum: The hazel tree shows a remarkable capacity to adapt to different soils, although its optimal development occurs in lands deep, fertile, humus-rich and well-drained. It prefers medium textures and avoids both sandy and heavy clay soils.
- Ideal pH: Between 6 and 7, slightly acidic or neutral. In very alkaline soils it may present nutritional deficiencies.
- Previous preparation: In regular plantations, it is advisable to carry out deep tillage, incorporating organic matter (mature manure) and, if necessary, amendments to correct the pH before planting.
Planting is preferably done during the vegetative dormancy, in autumn or winter, taking advantage of the fact that the root system is superficial and does not require very deep holes (no more than 20 cm), thus avoiding the risk of root asphyxiation. For more information on the planting process, how to plant hazelnut fruit, check out this resource.
Hazelnut watering: frequency and recommendations
El hazel needs the land to be always moist but never waterloggedIt is especially sensitive to drought, which can cause premature flower and fruit drop and reduce the harvest.
- Irrigation in seedlings and young plants: Maintain regular watering every few days, adjusting the frequency based on the weather and soil type. In spring and summer, periodically check the soil's moisture and water deeply when the top layer begins to dry out.
- Irrigation in adult specimens: Space out waterings but increase the amount, especially during dry periods and high temperatures. Techniques such as drip irrigation or irrigation bags allow for efficient and consistent watering, minimizing evaporation and promoting absorption by the hazelnut's surface root system.
- Avoid puddles: Make sure the soil drains properly and never water if the soil is still wet.
Avoid frequent shallow watering, as this can encourage the development of shallow, less drought-resistant roots. Ample, more spaced-out watering is preferable.
Fertilizing and fertilizing hazelnuts
La fertilization is key to obtaining healthy and productive hazelnut trees. Hazelnut trees especially require Calcium, without neglecting the balanced supply of nitrogen, potassium, phosphorus, and magnesium. Adapt the fertilizer to the soil conditions and the plant's needs.
- Organic fertilizer: Incorporate well-rotted manure into the soil every two years, especially in the fall.
- Mineral fertilizer: You can apply mineral fertilizers at three key times: during the start of budding, after flower fertilization, and after harvest.
- Guideline proportions (for regular plantations):
– 350-400 kg/ha of calcium ammonium nitrate (26%) in three main contributions.
– 200-250 kg/ha of potassium sulphate.
– 250-350 kg/ha of calcium superphosphate (18%).
– 100-200 kg/ha of magnesium sulfate.
Adapt these quantities to the needs of your garden or orchard, consulting soil analysis to avoid overfertilizing. - Calcareous amendments: If the soil is acidic, add agricultural lime to maintain optimal pH.
- Mulching: A layer of organic mulch in spring helps conserve moisture and reduce weed competition.
Recommended hazelnut varieties
The success of a plantation depends largely on the choice of varieties and plantation design to ensure efficient cross-pollination, since hazel is a generally self-incompatible species.
- International varieties: Negreta, Gironella, Pauetet, Osu 43-58, Ennis, Buttler, Tonda di Gifoni.
- Local varieties: Casina, Grande, Espinaredo, Quirós and Amandi, especially recommended in the north of the Peninsula.
- Pollination: Plant several compatible varieties grouped in lines or alternating specimens, allocating 15-20% of the plantation to pollinators to promote fruit setting.
- Ornamental varieties: Pendula (hanging growth), Aurea (golden foliage), among others.
Hazelnut training and pruning system
La pruning It is essential to control the size, promote aeration and lighting, and prolong the productive life of the hazel tree.
- Education Hazelnut trees can be trained in bushes (several trees) or in low vases from a single trunk, this method being preferred for ease of handling and harvesting.
- Formation pruning: During the first two years after planting, prune the seedling to a height of 40-50 cm and select 3 to 5 main branches.
- Maintenance pruning: From the beginning of training, periodically remove dry, damaged, crossed branches or excessive suckers to allow light to enter and prevent disease.
- Rejuvenation pruning: In adult hazel trees, severe pruning of a significant portion of the vegetation stimulates the release of young shoots and prolongs productive life.
- Pruning time: Perform the main pruning in winter, during the vegetative stop, and light touch-ups after the harvest.
Common pests and diseases in hazelnuts
Although resistant, the hazel tree can be affected by various pests and pathologies:
- Main pests: Bed bugs, aphids, bud moth, hazelnut worm, mites and wood borer (zeuzera).
- Diseases: Powdery mildew (white spots on leaves and shoots), root rot, lichens and bud drying.
- Control and prevention: Manually remove affected areas, use organic or conventional plant protection products depending on the severity, and keep the hazel tree well-aerated and nourished for greater resistance.
- Cultural measures: Keep the soil free of plant debris, control humidity, and alternate chemical treatments if necessary to prevent resistance.
Propagation and multiplication of hazelnut
Hazelnut can be propagated by:
- Seeds: Slow method used to obtain new cultivars.
- Layer: Very effective, it consists of burying a low branch that will produce its own roots before separating it from the mother plant.
- Graft: Used on selected rootstocks to ensure the characteristics of commercial varieties.
Nutrients and benefits of hazelnuts
- Nutritional contribution: Hazelnuts contain more than 50% healthy oils, proteins, sugars, and minerals such as calcium and magnesium.
- Food properties: They are an ideal complement to the diet, especially for active peopleIts oil is used in food and also in industry for the manufacture of paints and cosmetics.
- Storage: They are harvested when the shell turns brown and after drying, they are stored in cool, dry places.
In addition, the leaves have medicinal properties and can be used in infusion for traditional uses.
- History and symbolism: The hazel tree has been part of the European landscape and culture for centuries, considered a symbol of fertility and love.
- Spectacular flowering: Its male catkins provide ornamental value in the months before spring.
- Root system: It develops a shallow but highly branched root system, making it sensitive to weed competition and sudden changes in humidity.
- Production It begins to bear quality fruit after 3 to 5 years, reaching its maximum productivity around 6 or 7 years.
- Ornamental and hedge uses: In addition to being grown for consumption, it is popular in gardens as a dense hedge or as an isolated specimen for its beauty and rusticity.
Master the hazelnut care This will allow you to enjoy a robust, ornamental, and highly productive shrub or tree for decades, adding both landscape and nutritional value to your garden or orchard. By following these recommendations on location, soil, irrigation, fertilization, pruning, and pest prevention, you'll have a healthy, vigorous plant capable of producing abundant harvests of tasty hazelnuts season after season.