The olive tree in Greece has been cultivated for more than 6,000 years, as evidenced by the large pre-Minoan tree of Naxos, which has a trunk circumference of 29.0 meters and a maximum diameter of 10.8 meters.
During all these millennia and in combination with the various microclimates of our country, many varieties of olive trees were created and selected.
Although today the officially recorded number of Greek olive varieties does not exceed 45-50 varieties, the actual number of Greek olive varieties is more than 100. In other words, most Greek varieties are not yet officially registered.
This large gap is being filled by the "George Kostelenos Nurseries". Since 1991 they have been researching, recording, and evaluating all the Greek olive varieties they can find, while at the same time creating a reference olive plantation to study their agronomic characteristics.
In our catalogue you will find most of the Greek olive varieties we have and if you do not find the varieties you want, do not hesitate to contact us.
For even more information on Greek olive varieties, you can refer to our book 'Kostelenos George (2011). History, description, and geographical distribution of olive varieties in Greece. Pp 430', where 80 Greek varieties are described.
More than 1,600 olive varieties have been registered worldwide, with Spain and Italy accounting for around 50% of the total.
Among all these varieties there are notable varieties of worldwide distribution, such as the Spanish Picual and Manzanilla, the French Picholine, the Italian Frantoio and Leccino, but also many other lesser-known varieties with specific characteristics.
The most recent molecular studies show that most of the western Mediterranean olive varieties have their origins in the eastern Mediterranean area, i.e., that most olive varieties are derived directly or indirectly from eastern Mediterranean varieties.
This to a certain extent is to be expected because it has been known for years that olive cultivation began in the eastern Mediterranean. There is even more evidence for some western Mediterranean varieties, such as the famous Arbequina variety. According to Ramon Blanco (1927), the Duke of Medinaceli brought Arbequina from Greece to Spain about 500 years ago, from where it later became known worldwide as a Spanish variety.
However, based on newer evidence and contrary to what is said and written, olive cultivation seems to have started not from the Middle East, but from the Aegean and Greece in general. More information can be found in our book 'Kostelenos George (2015). The origin and domestication of the olive tree. Pp. 51.'
In our catalogue you can find many of the foreign olive varieties that are currently cultivated in various countries, some well-known and globally distributed and others less known.
In our nursery, we use for grafting both known clonal olive rootstocks and same our own selection which we have chosen for some very good characteristics. In any case, all rootstocks we use are propagated by leafy cuttings, because only in this case they retain their desired characteristics.
The reason we graft olive varieties on selected rootstocks is to give them desirable characteristics that they do not have, like:
a) Resistance to verticillium wilt and fungi that attacks wood,
b) Resistance to salty water and high soil moisture conditions,
c) Higher productivity,
d) Lower - dwarf plants,
e) Increase the size of the fruits in edible varieties, etc.
It’s recalled that grafting of plants is applied in four (4) main cases:
a) When the desired varieties are not easily propagated by cuttings, tissue culture, etc.
b) When it is necessary to replace the cultivated variety without uprooting the plants,
c) When the cultivated varieties need to have desirable properties which they alone do not possess, e.g., resistance to disease, salty water, etc.
d) Where the required logistical infrastructure and expertise is not available in the nurseries, or where the nurseries are of small capacity to justify the existence of costly infrastructure.
In Greece, olive grafting is widespread and applied almost exclusively on olive seedlings, the so-called "wild olive trees", because it is believed that these trees are more resistant to drought, pests and diseases and at the same time more vigorous and productive than own root trees.
This is not true at all because:
a) In Greece there are no longer any genuine 'wild olive trees' in the botanical sense of the term. Even when olive trees grow as single trees in the mountains, they are still not genuine 'wild olive trees' but 'tame olive trees', just as e.g., stray dogs are not real 'wild dogs' but 'tame' stray dogs!
b) The olive trees without grafting are not inferior to the grafted ones as far as longevity is concerned, but as the Greek scholar Nikos Lychnos wrote since 1949: 'The facts convince us to the contrary...'.
c) When olive rootstocks are derived from seeds, even from the same tree, young seedlings completely differ from each other with completely different properties which are not at all desirable. For example, we do not know the resistance they have to drought, pests and diseases, how they react to grafting etc.
In modern arboriculture, viticulture, horticulture, olive culture etc., complete uniformity of genetic - planting material is desirable and therefore 'clonal rootstocks' with known traits are used. In olive growing, clonal rootstocks may not yet be widespread, but this is the direction in which modern research is moving, and we are a world leader in this field.