A Detailed Tutorial on the Latest Hazelnut Planting Techniques and Methods
The hazelnut is a shrub or small tree of the genus Corylus in the birch family, one of the world's four major dried nuts, with strong adaptability, able to grow in mountainous areas, hilly land, gullies and riversides. Planted artificially, it begins to bear fruit in 2-4 years and enters full fruiting in 5-7 years; wild hazel stands reclaimed by hand show obvious economic returns in 2-3 years. It has very high prospects for cultivation. Let us take a look together at hazelnut planting techniques below!
Hazelnut Growing Conditions
1. Temperature: Different species of hazelnut trees have different temperature requirements. The European hazel (Corylus avellana) prefers a warm, humid climate. It is suited to areas with an average temperature of 13-15°C, an absolute minimum of -10°C, and extreme highs of 38°C. Ping'ou hybrids are more cold-resistant than the European hazel and are suited to cultivation in areas with an average annual temperature of 7.5-13°C and minimum temperatures down to -30°C.
2. Light: The hazelnut tree is a light-loving plant, generally requiring annual sunshine hours of more than 2100 hours, otherwise flower bud formation is reduced and yields are low.
3. Soil: The hazelnut tree prefers to grow on fertile, well-aerated sandy loam; the Ping'ou hybrid in particular has high soil requirements, and dry sandy soil, heavy clay soil, swamps, saline land and low-lying land are all unsuitable for establishing a hazel orchard. Ping'ou hybrids require a soil pH of 6.5-7.5, while the European hazel requires 5.5-7.
Hazelnut Propagation Techniques
1. Seed propagation: In wild hazel stands, select high-yielding, large-fruited, pest- and disease-free clumps as seed mother trees, and from them choose hazelnuts that are large, have plump kernels and are free of pests and diseases for sowing. Hazel seed germination power is retained for 1 year. Sowing is best done in spring, generally in mid-to-late April. For ridge planting the row spacing is 60 cm and the plant spacing 6-8 cm; for bed planting the row spacing is 20 cm and the plant spacing 5-6 cm. When sowing, first open a furrow on the leveled ridge surface, 5-6 cm deep. Then scatter the pure seed screened out of the damp sand into the bottom of the furrow at the above row and plant spacings, cover with 3-5 cm of soil, and press lightly.
2. Division propagation: There are two methods of division propagation. One is to dig up the entire mother plant and divide it into several small clumps or individual plants, each individual plant having a root system and 1-2 branches. The other is to dig up root suckers around the mother clump and separate out several plants while keeping the mother plant. Division seedlings should retain a 20 cm root section and a certain number of fibrous roots. After the division seedlings are separated from the mother plant, the branches should be cut short, leaving them 15-20 cm long, and they should immediately be heeled in to keep them moist and prevent water loss.
3. Root sucker propagation: There are two methods of root sucker propagation. One is to dig up the root suckers around existing clumps to obtain planting stock. The other is to propagate in a dedicated mother plant orchard. Mother plants intended for propagation should be cut back to the ground in spring to promote the production of root suckers in the clump. During the growing period, ensure an adequate supply of fertilizer and water, and thin appropriately so that the root suckers are not too dense, ensuring both that the root suckers develop and grow well and that it is easy to dig up the seedlings in autumn.
4. Layering propagation
① Horizontal layering: This can be done in autumn or spring, but spring is the most suitable time. Pull vigorous one-year-old branches out horizontally and lay them on the ground, fix them in place, and do not cover with soil. Carefully protect the leaf buds so that they sprout. In this way, almost all the buds on the horizontal surface can grow into new shoots. When the new shoots grow to 10-15 cm, wind soft iron wire 2-3 times around each node of the one-year-old branch (that is, the base of each new shoot) to promote new root formation. Then earth up the new shoots to two-thirds of their height, and earth up 1-2 more times later according to the growth height of the new shoots. After leaf fall in autumn, cut apart each node, and each becomes a seedling with a vertical new shoot and roots at its base.
② Arch layering: Arch layering is divided into hardwood layering and softwood layering. Hardwood layering is done in early spring: dig a trench 15-20 cm deep around the clump, scatter well-mixed rotted farmyard manure into the trench, and keep the trench 10-15 cm deep. The distance between the trench and the base of the clump should be such that when the branch is bent down, its lower-middle part can touch the bottom of the trench. Select well-developed one-year-old branches and bend them toward the bottom of the trench. Fix them in place, then cover with soil, fill the trench level and firm it. In this way, the branches and buds left above the ground sprout and grow, while the parts pressed in the soil take root. To promote good rooting of the branches, you can also girdle the part of the branch pressed at the bottom of the trench, 1-2 mm wide, removing the phloem, or make several transverse cuts. Softwood layering is done in early to mid-June, when the current-year basal shoots have grown to 60-80 cm; the method is the same as for hardwood layering.
Hazelnut Planting Management
1. Planting density: To make hazelnut trees achieve the goal of high yields, the planting density of hazelnut trees should be reasonable. The rational choice of hazelnut planting density is closely linked to many factors, such as species, variety, rootstock, cultivation techniques, tree form used, terrain, soil and climatic conditions. Therefore, when choosing the planting density of hazelnut trees, many factors must be considered so that the hazelnut trees can grow vigorously.
2. Planting density: In places with fertile soil and flat terrain, the planting distance of hazelnut trees should be larger; in mountainous hazel orchards with steeper slopes and poor soil, the planting row spacing can be smaller. For varieties with vigorous growth and an open canopy, the planting row and plant spacing should be larger; for varieties with weak growth and an upright, compact canopy, the planting row and plant spacing can be smaller. According to different cultivation purposes, the planting density should also differ. Some, for early high yields, can use planned dense planting, dense in the early stage, and later when the orchard canopy closes, thinning can be carried out.
3. Planting depth: For planting depth, the root system must not be buried too deep or too shallow; after planting, the root crown is required to be at ground level or slightly below the ground by 5 cm. A soil cover depth of 6-10 cm above the root system is appropriate. If the soil in the hole is loose, to prevent the soil from settling too much after watering and making the planting depth difficult to control, water appropriately before planting. Or tread the soil in the hole slightly firm with the foot.
4. Reasonable watering: Build a watering tree basin around the hazelnut tree, with a diameter of 1 m, to facilitate watering and water storage. After planting, water immediately, and water fully and thoroughly. After the water seeps down, cover with soil to conserve moisture, and cover the tree basin with plastic film to retain moisture and increase temperature, promote hazelnut root activity, and improve the survival rate.
5. Timely pruning: Keep one trunk, and afterward carry out training and pruning according to its own growth and development characteristics to form a reasonable framework. Generally 3 tree forms are used: the few-stem clump form, the single-trunk form, and the multi-stem clump form. In the few-stem clump form, keep 3-4 basal shoots as main branches, slanting out in different directions. On the main branches of the hazelnut tree, lateral branches grow, and on the lateral branches grow vegetative shoots and fruiting mother branches. The overall form remains an open-center tree form. In the single-trunk form, this tree form requires keeping one trunk, selecting and keeping 3-4 evenly distributed main branches on the trunk, selecting and keeping lateral branches on the main branches, and on the lateral branches grow secondary branches and fruiting mother branches, forming a short trunk.
6. Reasonable fertilizing: Apply rotted farmyard manure in early May, and topdress with compound fertilizer in mid-July. In the second year after planting, topdressing can be applied outside the projection of the canopy around the hazelnut tree; do not apply too deep.
7. Trunk heading after planting: After planting, head the hazelnut tree, divided into the single-trunk form and the clump form. Plots with good soil, fertilizer and water conditions are suitable for the single-trunk tree form, with a heading height of 60-70 cm; otherwise, the clump tree form is suitable, with a heading height of 30-40 cm. For seedlings planted in the current year, strengthen water and fertilizer management so that they grow and develop vigorously, sprout a certain number of branches, and lignify well, preventing the hazelnut tree from growing excessively. After leaf fall in autumn, earth up for cold protection, with the earth mound reaching 1/2 of the plant height. In the following spring, remove the cold-protection soil; generally from the second year on, earthing up for cold protection is no longer needed.