When chosing a soil to grow olive trees, proper drainage and soil type are crucial. Olive trees are best grown in non-layered, fine textured soils. Such soils have the capacity to retain water well, which is key for growing healthy olive trees. It is important to note that the root system of the olive tree is usually situated between 50 cm and 70 cm deep in the soil.
Water-penetration and drainage are best in shallow soils, which is why olive trees thrive in unstratified soils about 4 feet deep.Nothing more is required for the tree to grow to full maturity. However, growers must be careful of not over-saturating the soil, which is sure to kill the olive tree root and hence killing the tree. A dripper is often installed close to the trunk of the tree, in order to dispense just the right amount of water into the soil. The soil should be watered deep to make sure all the roots are receiving an appropriate amount of water.
As the tree grows, the dripper should be moved farther away from the trunk, in order to water and accomodate the tree's growing roots.
After reaching their full size, the olive trees are particularly well adapted to dry or even droughty climates, but should never be exposed to cold climates sinze frozen soil will most likely damage or even kill the tree. The trees should be protected from colder than usual temperatures as much as possible.
Ph level is also important when selecting a soil to grow olive trees. If the trees are tolerant of various Ph levels, they will yield the best and most olives in soils which have a moderately acid or alkaline ph.
1) University of California, Division of Agriculture and Natural Resources (http://ucanr.edu/sites/scmg/files/30942.pdf)
2) Olive Production Manual by G. Steven Sibbett
3) Production Techniques in Olive Growing by the International Olive Council