11 secrets for the cultivation of chestnut
The cultivation of chestnut has been known since antiquity for the sweet and delicious fruits of high nutritional value that it produces, the wonderful chestnuts. And surely, most of us have eaten roasted chestnuts during the winter.
The chestnut is an age-old deciduous fruit tree that belongs to the same family as the oak and can reach a height of 30 meters. It has a characteristic red-brown trunk and toothed leaves with oblong or oval shape. The chestnut fruit is located inside a thorny hard shell that opens when the fruits ripen. Chestnuts are eaten boiled or roasted, become an excellent flour and replace the potato diet. They are less fatty than other nuts and contain a lot of vitamins, proteins, minerals and fiber. The cultivation of chestnuts has several requirements, as well as the main crops of nuts: the cultivation of almonds, the cultivation of pistachios, the cultivation of walnuts and the cultivation of hazelnuts. Let’s see in detail the most important varieties of chestnut to cultivate and the required cultivation care to achieve a rich harvest of wonderful chestnuts.
What are the most important species and varieties of chestnut?
The most important chestnut species grown are Chinese chestnut (Castanea milissima) producing small chestnuts, European chestnut (Castanea Sativa) and Euro-Japanese hybrids (Castanea crenata X Castanea sativa) resulting from a cross between European chestnut and Japanese chestnut . Among the Euro-Japanese chestnut hybrids that come into fruition earlier in the 4th year after planting, remarkable varieties to cultivate are Marigoule, Maraval 74, Bournette and Vignols.
What conditions does the chestnut cultivation need to grow?
Chestnut cultivation thrives in semi-mountainous and mountainous areas with a relatively cold climate and sufficient humidity. It prefers sloping soils and sunny places where there are no spring frosts to which the chestnut is sensitive. Chestnut cultivation needs acidic soil with a pH around 5 – 6 to thrive and grow. We grow chestnuts in deep, fertile soils that ensure very good drainage and have a very low calcium content.
How is chestnut pollinated and fertilized?
The chestnut tree has male and female flowers and is pollinated with the help of insects and the wind. For efficient pollination, better fruit set and improved production, we prefer to grow two or more varieties of chestnut in our field. It is important to mention the phenomenon of heterosis in chestnut, as it significantly improves the size of the fruit. Specifically, when the fertilization of the female chestnut flowers is done with pollen from a large-fruited variety, the chestnuts produced are larger.
What season and at what distances do we plant chestnuts?
A good time to plant bare-rooted young chestnut trees is in the winter when the plant is dormant. For chestnut plants with a soil ball in a pot or nursery bag and include a soil ball, a suitable planting season is spring.
The planting distance is determined by the fertility of the soil, the chestnut subjects and the variety we choose. Indicatively we mention that the varieties of Chinese chestnut are planted at distances of 12 x 12 meters, the varieties of European are planted at distances of 10 x 10 meters, while the Euro-Japanese chestnut hybrids are planted more densely at distances of 7 x 7 meters. Before planting chestnuts, we add manure and compost to the field to increase the organic matter and nutrients. Soil analysis is also necessary to investigate possible data shortages and make more effective management. Then we open holes measuring 45 x 45 cm, plant the young chestnut seedlings and water very well.
How much watering does the chestnut crop need?
The cultivation of chestnut needs enough soil moisture, especially in the first years after planting to be able to develop a good root system. Therefore, regular watering is necessary in the early stages of cultivation, in the spring, summer and autumn. Watering is also important for large chestnut trees, as it helps their fruiting, both in terms of fruit size and overall production yield. Especially, watering is very important in early autumn, the growing season and the filling of the chestnut fruit.
What fertilizer does the chestnut crop want?
Chestnuts have significant needs for nutrients and fertilizer to give good production every year. For the proper fertilization of the chestnut, it is very important to do a soil analysis and foliar diagnostics every 3-4 years. Chestnut cultivation needs fertilizer rich in nitrogen and potassium, and less in phosphorus. A suitable season for basic fertilization is in March, while supplementary nitrogen fertilization can be done in late spring and summer. Additionally, the addition of a small amount of boron fertilizer to each tree, during the period of basic fertilization, or the application of boron foliar fertilizers significantly improves the fruiting of the chestnut.
What diseases and which insects affect the cultivation of chestnut?
Chestnut cultivation is affected by several fungal diseases such as melanoma, chestnut ulcer, carcinoma, charring and koryne. The disease of bruising, which is the most common disease of chestnut is due to fungi of the species Phytophthora and causes tearing of the bark, outflow of juice from the inside of the trunk that turns black, yellowing of leaves and drying of shoots. To prevent bruising on the chestnut, avoid excessive moisture in the soil and water the root with a solution of copper oxychloride or bordigal drink.
The cultivation of chestnut is mainly affected by the insects of the fruit capsule and the oak, whose caterpillars create characteristic holes in the chestnuts. For the biological treatment of chestnut insects, we make sprays with organic insecticides such as natural pyrethrum and summer pulp. Due to the significant damage done by these insects, many sprays are required during the growing season. It is also important to immediately remove and destroy infected fruits that fall to the ground to limit the growth of these insects.
What season and how is the chestnut pruned?
Suitable time for pruning chestnut is in late winter, in the period of February, when chestnut is still dormant. In very cold areas, the chestnut is pruned immediately after the last intense frost and can be done in March. The young chestnut trees are pruned in such a way as to form a cup-shaped tree where there is a central trunk 1 meter high, on which grow 3 central arms that form an angle of 50-60 degrees with the trunk. Although many growers do not prune large chestnut trees due to their high height, pruning helps to improve the vitality of the tree, renew fruitfulness and ensure greater production. With the fruiting pruning done on large chestnut trees, we try to maintain the shape of the tree, remove dry and diseased branches, branches that become entangled with each other and achieve more ventilation and exposure of the foliage to more sunlight.
How is the chestnut propagated?
The chestnut is propagated mainly by seeds to create the original plants and then grafted with the desired variety of chestnut. It should be noted that propagation by cuttings, as well as propagation by cuttings, shows a small success rate in chestnut. As the subject of the chestnut, we must use plants that came from seed and belong to the same species of chestnut with the variety that we will inoculate. The chestnut is inoculated by eccentricity with the method of subcortical coronary artery or by inoculation type T.
When do chestnuts ripen and how are they harvested?
The fruits are harvested in the autumn, from mid-September to late October. Chestnuts in Greece are mainly harvested from the ground by hand, although to ensure better quality it is good to harvest them from the tree. Fresh chestnuts can be stored for 3-4 weeks in the refrigerator before eating. If we boil them first, we can store them for 8-10 weeks in the refrigerator and up to a year in the freezer.
And one last secret for the cultivation of chestnut
The phenomenon of chestnut splitting before harvest is mainly due to abrupt changes in humidity conditions in the atmosphere and soil and not to the addition of nitrogen fertilizers as in other cases of fruit trees.