If you have never seen an olive tree look for an evergreen tree with leaves that are dark green on the top and covered with much lighter silver scales on the underside. It was this silvery colouring, shimmering in the breeze, that attracted the attention of the artist Van Gogh. Fascinated by their colour, he painted pictures of olive trees.
The trees are slow to grow, taking four or five years to yield their first fruits and another ten to 15 to reach their full capacity. Once established, however, the olive tree can live for many years.
There are stories of trees which have stood for 1000 years. Some trees are known to have been around for 100 year of more, but really old trees are more likely to be the result of new shoots springing up from root systems which have survived the ravages of age or bad weather.
The unripe olive fruit is pear-shaped and green in colour, changing to dark purple or black as it ripens. All olives, if left on the tree, will follow this pattern. Green table olives are picked an cured before they have ripened. Others are left on the trees and picked when they are fully ripe.
Olives which are to be pressed for oil may be picked at any stage in their development but the yields from unripe olives will be very small an die oil can be very bitter. Most olives are therefore left to ripen fully.