Olive in pot
The olive tree is an evergreen plant among the most long-lived (about 1000 years) and its fruits were used in ancient times as food and to obtain oil. Given its high content of polyphenols, however, for food use it is necessary to treat the olives to reduce their bitter taste. The olive has a slow growth but continues throughout the year, even if in winter it slows down its activity. The slow growth and the extended and superficial roots (do not exceed the depth meter), make the olive a plant particularly suitable for growing in pots. The price of a 3-year-old olive tree, 80 cm high, is around 30 euros.
Exposure and irrigation
The olive tree prefers the warm temperate climates characteristic of the Mediterranean area, but with the appropriate precautions it can also be cultivated in other areas, as long as they are not too cold or particularly humid. There olive plant it must be exposed in a sunny place, preferably facing south and away from cold winds. In the case of olive trees in pots, during the winter it is advisable to place the plant near a wall or a window of the house to provide more heat. To preserve the olive from winter frosts it is also a good idea to spray copper oxychloride on the leaves: in doing so the substance will act as a second skin to the leaves of the olive making the plant more resistant to cold. Needing little humidity, the olive does not have any particular problems during periods of drought, even if prolonged, especially if the plant is adult and planted directly on the ground. For the olive tree more care is needed: during its first years of life it is necessary to water the plant every 2 weeks in summer and once a month in autumn, while it should not be irrigated in the winter months. In general, irrigation should be done only when the soil is dry and sparingly, since the olive tree hates stagnant water.
Fertilization and repotting
The olive is a plant capable of adapting to different types of soil, as long as it is drained and rather adapted and preferably calcareous. The olive tree in the container needs instead a more specific soil, particularly draining and light, made up half by universal soil and half a mixture of sand, peat, lapillus and mature manure. After preparing the soil, the plant will be fertilized at the beginning of spring using a liquid fertilizer based on 30% -10% -20% nitrogen, phosphorus and potassium to be administered together with water to water. During the other periods of the vegetative season (from spring to late autumn) fertilization will be carried out only in the case of traumatic events for the plant such as repotting, attack by parasites or incorrect exposure, which could cause the loss of the leaves. The olive also requires intervention during the winter: it is advisable to place a mulch of straw or foliage at the base of the olive tree to protect the roots from the cold since the potted plant is less protected than the earth due to the amount of soil lower. Every year it is advisable to replace the surface layer of the soil, gently to avoid damaging the roots. In the first years of life of the olive tree, repotting is carried out every two years, but the more the plant becomes adult (after 50 years), the more the interval between one repotting and the other increases.
Pruning and multiplication
The olive pruning mainly has the function of giving the plant the desired shape and size. In the early years the pruning must be annual, but they thin out over time until they are limited to cutting wasted, sick, dry or irregular branches (especially the branches that grow inward and the suckers, branches that grow parallel to the trunk). In the case of diseases before intervening with pruning it is possible to adopt less drastic remedies. If the plant is hit by the peacock eye (fungus that attacks the leaves until they fall) it can be cured with a compound based on salts and lime), while the cochineal (insect that attacks the leaves sucking the sap) can be counteract by manually cleaning the plant with alcohol soaked cotton, an effective treatment only in the case of limited attacks, otherwise specific insecticides or solutions containing white oil should be used. To create new olive trees, the easiest method, at least for amateur uses, is the cutting. Alternatively, multiplication can take place using any suckers (full branches of leaves that depart from the base of the olive tree trunk).