Olive trees are popular drought-tolerant landscaping plants valued for being evergreen and for their picturesque gnarled branches. Olive trees are small enough to fit in most yards. Mature trees typically reach a height of 18 to 25 feet and a width of 12 to 15 feet. In addition, olive trees are relatively easy to transplant, allowing installation of full-grown trees around new construction. Although there are innumerable agricultural olive varieties, comparatively few olive cultivars are used in landscaping.
The Manzanillo olive tree is the most common agricultural variety in the California olive industry and is also grown by homeowners. This cultivar originated in Spain, where it is also a common agricultural olive. Certain diseases of olive trees, including olive knot and Verticillium wilt, strike the Manzanillo particularly hard. Its copious fruit production make the Manzanillo a good orchard plant but a messy landscaping tree. The ripe fruit can stain sidewalks, and the trees also produce a large amount of allergy-inducing pollen.
The Mission olive variety is an agricultural olive that also is used as an ornamental plant. Like the Manzanillo, Mission olive trees can become a nuisance when used in landscaping due to fruit debris and excess pollen. However, this variety is comparatively cold-tolerant, growing easily in northern California.
The Swan Hill olive comes from the town of Swan Hill in Australia. This unusual variety of olive produces only male flowers and therefore cannot bear fruit. In addition, the male flowers produce very little pollen. The lack of fruit litter and low allergenicity make the Swan Hill olive tree a popular landscaping olive. However, because the variety if fruitless, nurseries can produce new trees only through grafting or cuttings. Swan Hill is also somewhat cold-tender, tolerating temperatures only to around 15 degrees Fahrenheit. Most other olive varieties are cold-hardy to around 10 degrees Fahrenheit.
Wilson's olive is a ornamental variety that typically produces no fruit. In some years, this variety will give a small number of olives. Pollen production is also low. Like the Swan Hill olive, Wilson's olive must be propagated artificially.
Majestic Beauty is a fruitless olive very similar to Wilson's. This type of olive forms a more compact tree than most agricultural varieties. Smaller leaves also give the Majestic Beauty a more open canopy.
In addition to olive trees, there are also shrub-like olive varieties that can be grown as hedges, reaching up to12 feet in height. Common dwarf olives include Little Ollie, Montra and Skylark. Many dwarf olives are fruitless.