Olive trees, ‘Olea europaea,’ are the oldest fruit trees and certainly are one of the most important fruit trees in history. Olive tree culture has been closely connected to the rise and fall of Mediterranean empires and other advanced civilizations throughout the ages. Because olive trees offered wealth and future food supplies to established civilizations, the agricultural nations became stable societies, resulting from a secure expectation from past experience of an uninterrupted food and olive oil supply. This factor was a necessary requirement for population growth and increase. Dependable fruit production and olive oil production means that olive trees must exist in a stable society and a peaceful environment. That stability must extend for many years, since most ancient seedling olive trees required eight or more years before ever producing the first crop of fruit.
Productive orchards of olive trees meant that a foundation of the great empires of Greece and Rome had arisen and developed into complex economic and political forces. It is interesting to note that the historical decline of these empires corresponded to the destruction of their olive tree orchards that reduced the available supplies of olives, olive oil, olive wood, and olive soap. In connection with the destruction of olive orchards, it is interesting to note that in the Israeli wars with Palestine, 50,000 olive trees were destroyed by Israeli bulldozers. That act of agricultural destruction resulted in considerable anger and unrest along the Gaza strip and the West Bank, because the economic livelihood of many Palestinian farmers depended on their products from the uprooted olive trees. Additionally, the olive tree was historically a ‘peace and goodwill’ symbol, and when the olive trees were leveled near the city of Bethlehem, the birthplace of Jesus and the “Cradle of Biblical History,” that elimination of olive trees seemed like a deliberate provocation to end the ‘peace’ with the Palestinian settlers and farmers.
Medical properties of olive oil were reported by many ancient Hindu and later Greek writers and philosophers, their importance in creating nutritional benefits and wealth for Greek citizens continues abundantly today–some Greek olive tree orchards containing a million or more trees. Aristotle wrote extensively about the accepted methods of successfully growing olive trees.
Greek mythology records that Athena, the Goddess of wisdom and peace, struck her magic spear into the Earth, and it turned into an olive tree, thus, the location where the olive tree appeared and grew was named Athens, Greece, in honor of the Goddess, Athena. Local legend tells us that the original olive tree still stands growing after many centuries at the ancient sacred site. Citizens still claim that all Greek olive trees originated from rooted cuttings that were grown from that original olive tree. Homer claimed in his writings that the ancient olive tree growing in Athens was already 10,000 years old. Homer stated that Greek courts sentenced people to death if they destroyed an olive tree. In 775 BC Olympia, Greece, at the site of the ancient Olympic stadium, athletes competed and trained, and winners were triumphantly acclaimed and crowned with a wreath made of olive twigs. Ancient gold coins that were minted in Athens depicted the face of the Goddess, Athena, wearing an olive leaf wreath on her helmet holding a clay vessel of olive oil. The Greeks began olive cultivation in 700 BC.
The sacred lamp that was used in ancient Greek culture for lighting dark rooms at night was fueled by olive oil. Aged olive oil was also used in sacred anointing rituals of the church at weddings and at baptisms. Herodotus wrote in 500 BC, that the growing and exporting of olives and olive oil were so sacred that only virgins and eunuchs were allowed to cultivate orchards of olive trees. The first documented plantings of olive trees may have occurred during the Minoan civilization on the island of Crete and are believed to have been growing around 3500 BC. That civilization predates the discovered Mycenae olive fossils from 1600 BC and later in the Greek empire. Sturt Manning, an archeologist from Cornell University, reported in Live Science Magazine (Apr 28, 2005) that the most devastating volcano in 10,000 years occurred on the Greek Island of Thera, after which the city of Akrotiri was totally buried by the falling ash. The finding of olive wood and olive seed fossils buried near the site has shown through carbon dating that the volcanic eruption occurred between 1660 and 1600 BC and may have contributed to the total destruction of the advanced Minoan civilization (Atlantis) on the isle of Crete and may have led to the formation of the Sahara desert in North Africa after vaporizing the native forests there.
The fragrant flowers of olive trees are small and creamy white, hidden within the thick leaves. Some cultivars will self pollinate, but others will not. The blossoms usually begin appearing in April and can continue for many months. A wild, seedling olive tree normally begins to flower and produce fruit at the age of 8 years. The fruit of the olive tree is a purplish-black when completely ripe, but a few cultivars are green when ripe and some olives turn a color of copper-brown. The size of the olive fruit is variable, even on the same tree, and the shape ranges from round to oval with pointed ends. Some olives can be eaten fresh after sun-drying and the taste is sweet, but most olive cultivars are bitter and must be treated by various chemical solutions before developing into edible olives. If the olives are thinned on the limbs of the trees to 2 or 3 per twig, the ultimate size of the olives will be much larger. The fruit is gathered in mid October and should be processed as soon as possible to prevent fermentation and a decline in quality.
The leaves of olive trees are gray-green and are replaced at 2-3 year intervals during the spring after new growth appears. Pruning yearly and severely is very important to insure continued production. The trees have the unproductive limbs removed, so that it will be more fruitful. An olive tree can grow to 50 feet with a limb spread of 30 feet, but most growers will keep the tree pruned to 20 feet to assure maximum production. New sprouts and trees will emerge from the olive tree stump roots, even if the trees are cut down. Some olive trees are believed to be over a thousand years old, and most will live to the ripe old age of 500 years.
Olives generally are beaten off trees with poles, harvested mechanically or by shaking the fruit from the trees onto canvas. Most ripening olives are removed from the trees after the majority of the fruit begins to change in color. It is important to squeeze out the olive oil within a day after harvesting or else fermentation or decline in flavor and quality will occur. The olive oil can be consumed or used in cooking immediately after its collection from the press. Olive oils are unique and distinct, each brand of olive oil having its own character, as determined by many factors, like those unique flavor differences found in fine wines. Prepared commercial olive oils can vary greatly in aroma, fruit flavor; whether the taste is, flowery, nutty, delicate, or mild, and the coloring of olive oil is quite variable.
Olive oil produces many health benefits when used in cooking or when poured over salads. The use of olive oil can improve digestion and can benefit heart metabolism through its low content of cholesterol. Experts claim that olive oil consumption will cause a person to grow shiny hair, prevent dandruff, prevent wrinkles, prevent dry skin and acne, strengthen nails, stop muscle aching, lower blood pressure and cancel out the effects of alcohol.
Olive trees can survive droughts and strong winds, and they grow well on well drained soils up to a pH of 8.5 and the trees can tolerate salt water conditions. In Europe, olive trees are normally fertilized every other year with an organic fertilizer. Alternate bearing can be avoided by heavy pruning and generally the trees respond to this very quickly and favorably.
Olive trees should be purchased that have been vegetatively propagated or grafted, because the seed grown trees will revert to a wild type that yields small olives with an insipid taste. Olive trees are more resistant to diseases and insects than any other fruit tree and, therefore, are sprayed less than any other crop.
Even though commercial production of olives in the United States is only 2% of the world market, great interest in growing olives throughout the South has been stimulated by the recent introduction of promising cold hardy olive trees from European hybridizers. Many European immigrants to the United States grow their own olive trees in large pots, that can be moved in and out of the house during seasonal changes.