California Invasive Plant Council

Olea europaea

Common names: olive

Olea europaea (olive) is a shrub or tree (family Oleaceae) with fleshy one-seeded fruits that are spread by birds and mammals. It is native to African, temperate regions of western Asia, and the Mediterranean region of Europe. Trees are characterized by having grey bark and thick, leathery broadly lanceolate leaves that are dark green above and grey below. Though commonly grown as a crop in California, olive has escaped and naturalized widely in southern California and the Central Valley where it can invade grasslands and shrublands. Gardeners should use caution planting olives near open space and consider seedless varieties of this species instead.

Cal-IPC Rating: Limited?

Explanation of Cal-IPC ratings

• High – These species have severe ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal and establishment. Most are widely distributed ecologically.
• Moderate – These species have substantial and apparent-but generally not severe-ecological impacts on physical processes, plant and animal communities, and vegetation structure. Their reproductive biology and other attributes are conducive to moderate to high rates of dispersal, though establishment is generally dependent upon ecological disturbance. Ecological amplitude and distribution may range from limited to widespread.
• Limited – These species are invasive but their ecological impacts are minor on a statewide level or there was not enough information to justify a higher score. Their reproductive biology and other attributes result in low to moderate rates of invasiveness. Ecological amplitude and distribution are generally limited, but these species may be locally persistent and problematic.
• Alert – An Alert is listed on species with High or Moderate impacts that have limited distribution in California, but may have the potential to spread much further.
• Watch – These species have been assessed as posing a high risk of becoming invasive in the future in California.

CDFA Rating: None?

Explanation of CDFA ratings

• A – A pest of known economic or environmental detriment and is either not known to be established in California or it is present in a limited distribution that allows for the possibility of eradication or successful containment.
• B – A pest of known economic or environmental detriment and, if present in California, it is of limited distribution.
• C – A pest of known economic or environmental detriment and, if present in California, it is usually widespread.
• D – An organism known to be of little or no economic or environmental detriment, to have an extremely low likelihood of weediness, or is known to be a parasite or predator.
• Q – An organism or disorder suspected to be of economic or environmental detriment, but whose status is uncertain because of incomplete identification or inadequate information.
• * – An asterisk next to the rating indicates that a plant is included in the CCR Section 4500 list of California State Noxious Weeds.
• -* – This plant is included in the CCR Section 4500 list of California State Noxious Weeds, but is otherwise not rated.

More details

Assessment(s)

Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Weed Management Notes

• Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

• Don’t sell a pest: A new partnership to prevent plant invasions through horticulture. Connick, Sarah; Gerel, Mike. Vol 13, Issue 2

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

• Control of invasive plants after the Scorpion Fire on Santa Cruz Island. Woolsey, Jay; Parker, Mike; Carter, Katy; Little, Annie; Cowan, Clark (2022)
• Controlling the Invasive Offspring of Historic Olive Trees on Santa Cruz Island, Channel Islands National Park. Power, Paula; Roberts, James R.; Cowan, Clark; Rudolph, Rocky (2010)
• Partnering to prevent invasions of plants of horticultural origin. Connick, Sarah; Gerel, Mike (2004)
• The abundance and distribution of non-native woody species in Sacramento Valley riparian zones. Hunter, John C.; Sterling, John C.; Widdowson, William P.; Beedy, Edward C.; Stralberg, Diana; Nur, Nadav (2003)

Other Olea europaea Information

• CalPhotos - Images of plants taken mostly in California.
• Calflora - Distribution map and records of this species in California.
• CalWeedMapper - Distribution map of this species in California with ability to determine regional priorities.
• EDDMapS - Distribution of this species in North America.
• Jepson Interchange - Information on this plant's taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
• USDA PLANTS Database - Information on identification and distribution, with links to websites in individual states.

Additional photos