Olive trees are known throughout the world, thanks to the tree's prominence in stories that originate in the Mediterranean. The olive tree is a long-lived variety. Some species are thought to be more than 2,000 years old. Olive trees are grown primarily in the South in the United States because the tree will not grow above USDA Hardiness Zone 8. Olive trees suffer damage when temperatures get below 17 degrees F and will die in temperatures of 12 degrees F or lower.
Take a cutting from an olive tree branch that is as thick as a pencil. Clip the last 6 inches from the branch. Strip the lower leaves from the branch. Dip the branch in a rooting hormone.
Fill a 4-inch seedling container with peat moss. Insert the cutting halfway into the container. Water the soil until it is as damp as a wrung-out sponge. Place a 1-gallon freezer bag over the container. Place the container it in a sunny windowsill out of direct sunlight. Remove the bag once the plant forms roots.
Plant the olive tree cutting in well-drained soil and full sun. Dig a hole for the olive tree that is twice as wide as the tree's root ball, but no deeper. Spread the roots of the tree out through the planting hole and cover with soil. Water until the soil is as damp as a wrung-out sponge.
Check the tree weekly until the it becomes established. Water anytime the soil seems dry. Taper off watering when the tree becomes established.
Prune the olive trees in early spring to remove all dead or diseased limbs. Remove spindly or weak growth, limbs that rub one another or cross through the tree's central canopy.
Mulch olive trees to 1-½ feet up the trunk to protect the trees from cold. Continue to do this until the trees are 5 years old. Change the mulch seasonally to avoid creating an environment for disease.