L’olivier est immortel; la seule façon de le tuer est de le noyer – François Boutroux
The most important thing is good drainage: The olive tree grows best on slopes when the water runs thru them. The soil should not hold water, like clay. If potted, the water needs to be able to drain through the holes at the bottom of the pot. Potted trees need to be watered more often than trees planted in the ground. The olive tree does like alkaline soil and strives in limestone but there needs the minerals that can be found in commercial potting soil; you can use any water to water them. Best is to ask your local garden center.
The olive tree needs air, light, sun, heat and water – Corine Boutroux
Unpacking and caring for your olive tree when you receive it, with Jay