Olea europaea, or Olive tree, is an evergreen tree native to the Mediterranean Region. It is a small tree and will only reach about 25-30 feet (7-9 m) tall. When the trees are young, they have a smooth gray bark, but as they age they become increasingly gnarly looking. The elliptical to lanceolate leaves are gray-green above and silvery beneath and will reach up to 3 inches (7.5 cm) long. Olive trees have a long history in the Mediterranean Region, where they is the principal source of olive oil. Each village or region has its own olive oil, which differs in taste from the others. They are easy to culture and make great container plants. Our tree is 7 years old from a cutting and is only 6 feet tall in a 5-gallon container. Olive trees are hardy down to 15° F (-11° C) and will live in USDA zones 9-12.
Blooming In the spring. The small white, fragrant flowers are followed by up to 1 ½ inch (3.8 cm) glossy black fruits.
Culture: Olea europaea need full sun and a deep well-drained, rich soil. In the greenhouse, we use a soil mix consisting of 2 parts peat moss to 2 parts loam to 1 part sand or perlite. Even though the plants are very drought tolerant, we water them at least twice a week and fertilize them monthly with a balanced fertilizer. During the winter months, water is restricted to once every 2 weeks and the plants are moved to the cool room where the nighttime temperature goes down to 48° F (9° C). The fruit from olives can be very messy. The fruits will stain walkways and are harmful to grass and other plants growing underneath them.
Propagation: Olea europaea is propagated in the spring from softwood cuttings with bottom heat or from seed.
Olea europaea was featured as Plant of the Week November 12-18, 2004.
Guide to Past Plants-of-the-Week:
Cal's Plant of the Week was provided as a service by the University of Oklahoma Department of Microbiology & Plant Biology and specifically the late Cal Lemke, who used to be OU's botany greenhouse grower and an avid gardener at home as well. If the above links don't work, then try the overview site. You may also like to look at the thumbnail index. ©1998-2012 All rights reserved.