The olive is an evergreen plant that can grow as a shrub, hedge, or tree. Olive trees can grow as tall as 30 feet. Olives bear small pitted fruits that can be cured for table consumption or pressed for oil. Some olives are grown for ornamental use, often as shrubs or hedges--the olive's narrow gray-green leaves offset the dark green of most gardens and the olive's branching is noted for its billowing form.
Olive trees grown for their fruit are best trained and pruned to a manageable height--from 12 to 15 feet tall--the shorter stature will allow for an easier harvest.
Pruning olive trees.Olive trees fruit along one-year-old wood usually at the periphery of the tree canopy. Prune each year to encourage wood that will fruit. Thin out broken, diseased, and unproductive wood. Head back drooping wood and prune out water sprouts. Olives are best trained on trunks 3 to 4 feet tall with 3 to 4 scaffold or main lateral branches trained or pruned to different direction beginning at about 4 feet from the ground. (Multi-trunked olives are often used ornamentally, but can be kept to a manageable height for harvesting. Don't allow multi-trunked trees to grow too dense in the center.)
Train and prune olives to an open center allowing sunlight to reach deep into the crown of the tree. Remove basal sprouts; pull them away don't cut them to make sure they do not regrow. Rub off buds near the ground level that may become suckers. Olives that go unpruned will become densely twigged and crowded.
When to prune.Prune olive trees in early spring before buds and flowers set. Olive trees can be thinned any time of the year without damaging the tree. However, if you prune in late spring or summer after flowering, the harvest is likely to be decreased. You can prune in winter if the weather is frost-free and dry. Prune in dry weather to allow cuts to heal before frost or rain. Regularly pruned olives will require less pruning and thinning than trees that have been neglected. In regions with severe droughts, pruning in summer will reduce the number of leaves competing for water and may enhance the harvest.