Origin: Southern Europe, Near East. Habitat: the olive tree demands a Mediterranean climate, with long, hot and dry summers, and winters not toot cold; the ripening of fruits asks for a big sunstroke. The rainfall level in winter does not bother this robust tree, which must, in summer, accept 200 at least mm of water. The olive tree fits to all types of soils, except the humid soils. Nevertheless, it prefers stony soils. Lifespan: 2000 years. It is one of the trees most long-living (with the yew tree), and of very slow growth. Hardiness: zone 7 (it supports cold until -17 °C or 1 °F). Height: 10-12 m tall. The olive tree is often pruned to limit its size to 4 - 5 m to make easier the harvest of fruits. Trunk: very tortuous and wiry on elderly plants. Bark: grey, deeply cracked.
Persistent foliage: sharpened leaves, silver green, of 3 cm. Blossoming happens in May (only 2 % of flowers fructifie). Risk of allergenic pollen : medium to strong , depends on the region.
Fleshy fruit containing the stone: the olive is a drupe. Word "drupe" comes from Latin drupa which indicated the olive. Olives mature only in autumn or at the beginning of the winter. The olive, green at the beginning of the fructification, acquires by maturing a purple then brownish colour.
Use: olive, green or black, natural or seasoned, part of Mediterranean culture since the highest antique. The olive oil is also very reputed for its advantageous properties for the body, not only in feeding, but, also, and already in the Egyptian antiquity, in ointment, to treat dermatosises. Leaves contain active principles.
In Celtic astrology, the olive tree is wisdom. Legends and traditions: In the Old Testament, the dove dropped by Noé brought Olive tree's stem, which announced the end of the flood. In Greek mythology, the first Olive tree was planted on the Acropolis by the young Pallas, hence the symbol of chastity; Heracles planted one to Olimpie.
He used a mace in Oliver. At The Olympic Games (so in Olympia), the winners received a crowns made of leaves of Olive tree (while in the Pythian games, at Delphi, the victors received a laurel crown and at the Isthmian Games, at Corinth, they received a pine crown). In the Scriptures, the Cross of Christ was made in Cedar, for the cross and olive wood for the stake. Diseases:
Illness said about the eye-of-peacock is due to a mushroom. Leaves are blotchy of brown smears encircled with black and the foliage ends up falling.
The struggle against the mushroom is made with the aid of the classical fungicidal treatments.
Another illness is caused by the calyx of the olive tree which lays her eggs in fruits. Preventive treatment to fight this parasite will be in July after petal fall spray of an attractive blend (Bluminal 0.12L to 10L of water) and insecticide (Lebaycid 0.05L to 10L of water). Curative treatment is based on dimethoate at a dose of 0.075L/HL. Attempts are being made to acclimate a wasp in the Mediterranean basin to fight against this parasite: the females of this insect (Opius concolor) lay their eggs in the larva of the fly, which is slowly eaten alive. This biological control avoids the use of insecticides.
Other symptom: kinds of pustules appear on stems.
It is not pustules but insects, specifically the black scale of the Olive Tree (Saissetia oleae). It feeds on the sap of the tree through its proboscis (needle so acting pump). If nothing is done, the olive tree will eventually wither away as the cochineal multiplies very quickly. The best treatment is the application by spraying an oil insecticide specific (anti-cochineal). However, there is also another way which involves release of "wasps" called Metaphycus bartletti which are natural parasites of scale insects.