Olea europaea

Olive is a slow-growing, broadleaf evergreen tree or shrub that has a gnarled trunk, silvery-colored leaves, and a rounded crown. Olive is native to the Mediterranean, Africa, and China. The genus name, Olea, is derived from the Latin word for olive. The specific epithet, europaea, means “European.”

Olive performs best in hot/dry summers and mild/wet winters. Olive prefers fertile, well-drained soils with average moisture in full sun. They are drought tolerant once established. It can be grown outdoors in zones 8 to 10 or brought indoors or into a greenhouse in colder areas. It requires 2 months of temperatures in the 40 to 50 degree Fahrenheit range to flower. If you plan to harvest the fruits, it is recommended that you plant two different varieties (pollinizers) for cross-pollination to increase your crop yields. They are propagated by seed or semi-ripe cutting.

It grows 20 to 30 feet tall and 15 to 25 feet wide. The leaves are grayish-green on the upper surface and silver on the undersides and are elliptical to lanceolate. Small white, fragrant flowers bloom in the summer in 2-inch-long panicles. The fruit is a green drupe that ripens to a purplish-black. The fruits can be harvested at either stage and are important commercially as edible fruit, for making olive oil, and fuel. Olive branches are a symbol of peace.

The olive may be grown as an ornamental, fruit tree, container plant, or used in bonsai. There are cultivars available that may be grown in plant hardiness zones 7a and 7b. Some cultivars have no fruit or flowers. Fruiting trees planted near hardscapes can be messy. The tree has been introduced in many parts of the world. It can form dense stands and is reported to have become invasive in Australia, New Zealand,  Hawaii, and southern California.

Quick ID Hints:

• 20 to a 30-foot-tall tree with a rounded crown
• young trees have smooth gray bark, older trees are gnarled
• 3-inch long gray-green, leathery, elliptic to lanceolate, opposite leaves
• small white flowers that appear in 2-inch panicles
• 1.5-inch green oval drupes that ripen to black

Insects, Diseases, and Other Plant Problems: The olive has no serious insect pests or diseases. Monitor the tree for olive knot, verticillium wilt, and root rot. Scale insects may be a problem.

VIDEO created by Andy Pulte for “Landscape Plant Identification, Taxonomy, and Morphology” a plant identification course offered by the Department of Plant Sciences, University of Tennessee.