Planting
Olive trees like soil that drains easily, like a cactus mix. Placing a inch or two of styrofoam, gravel, or any other kind of filler on the bottom of the pot will keep the soil well drained. (And of course, make sure your container has plenty of drainage holes.) Although olive trees grow quite slowly, you want to make sure that the container is at least several inches larger than the root ball on each side to allow the roots room to expand. Planting in a larger container will mean you’ll have to re-pot your tree less often.