Weed Identification: Olive Trees

The African (Olea europaea subsp. Cuspidate) & Common Olive (Olea europaea) are significant weeds in South Australia & New South Wales and are currently beginning to spread throughout the Mornington Peninsula. Typically growing under powerlines (beneath perched birds), Olive trees are spread by birds & foxes. Olive trees form large, dense monocultures, transforming ecosystems & outcompeting native vegetation. They will usually grow between two to ten metres tall. Common olive (Olea europaea subsp. europaea) has leaves with silvery-grey undersides and pointed tips. African olive (Olea europaea subsp. cuspidata) has leaves with pale greenish-brown undersides and prominently hooked tips.

Like most weedy trees, a variety of techniques can be used to manage Olive Trees. Hand removal (ensuring the weeds are left without the weeds touching the soil), spraying with a registered herbicide (most efficient when the plant is below ankle height), drilling & filling (drilling holes in a circular fashion around the base of the trunk & filling with a registered herbicide) & lastly, cutting and painting. When removing any weed by hand it is important to attempt to cause minimal disturbance to the soil to reduce the spread of other weeds. If you notice you have Olive Trees growing on your property that you have not planted, it is best to manage them early before they become a problem. Indigenous plants such as Banksia spp. & Hakea spp. are great alternatives. The Shire Nurseries are a great place to buy Indigenous plants to fill your gardens with!