Olive trees are not usually traded by age but by their girth.
Until the age of 15 to 20 years the trees have a smooth trunk with olive-green colour. As they age, the bark becomes rough and wrinkled, and loses its fresh olive green colour.
These features distinguish young trees from old ones.
The Milenario is a stately ancient tree, without a specific age, but frequently several hundreds of years old. Because of their age, these trees develop a majestic and unique appearance that clearly distinguishes them from the others.