African olive (Olea europaea subsp. cuspidata)

African olive is a long-lived small tree or shrub with a dense canopy. It invades bushland and shades out native plants.

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How does this weed affect you?

African olive trees

• invade bushland and produce dense shade that suppresses native understory plants
• can permanently change plant diversity in bushland
• may harbour diseases and pests of commercial olives 
• do not have edible fruit.

What does it look like?

African olive is a much-branched evergreen shrub or small tree with a dense canopy. It is usually 5-10 m tall.

Leaves are:

• green or yellow-brown underneath
• 6-10 cm long and 10-25 mm wide
• glossy grey-green on top
• often with a hooked tip
• opposite on the stem.

Flowers are:

• yellow-white to creamy white with 4 petals
• 2-4 mm diameter
• on a short stem
• present in spring and summer.

Fruit are:

• 15-30 mm long and 6-20 mm wide
• round with a sharp tip at the base
• green with white spots when unripe
• purple-black when ripe with one seed.

Seeds are:

• brown
• 10-15 mm long
• oblong
• hard.

Stems are:

• silvery-green
• mostly upright
• smooth or slightly ribbed when younger
• covered in rough, light or dark grey bark when older.

Similar looking species

African olive looks like several other olive trees.

• Common olive (Olea europa) has leaves that are silvery-grey underneath and with pointed tips
• Native mock olives (Notelaea venosa and Notelaea longifolia) have leaves which are much bigger and have a leathery texture. Notelaea longifolia has hairy leaves.
• Feral olive Olea europaea subsp. europaea is also a weed with similar impacts to African olive.

Where is it found?

African olive grows throughout NSW. The worst infestations are around southwest Sydney and the central Hunter Valley. It has naturalised along the whole of the western slopes from north to south.

In the 1800s it was introduced to Australia as a hedging plant and as root stock for edible olives. African olive first naturalised along coast between Milton and Lismore. It is a tropical wild olive that comes from eastern Africa.

What type of environment does it grow in?

African olive prefers warm temperate and semi-arid regions. It can grow in dense shade.

Maps and records

• Recorded presence of African olive during property inspections (Map: Biosecurity Information System - Weeds, 2017-2023)
  These records are made by authorised officers during property inspections under the Biosecurity Act 2015. Officers record the presence of priority weeds in their council area and provide this to the NSW Department of Primary Industries. Records reflect the presence of the weed on the date of inspection.
  
  

How does it spread?

By seed

Birds eat the fruit and spread the seed.

By plant parts

African olive produces suckers when trees are damaged.

References

Keech, G. G. (2007). An Investigation of Application Techniques for the Control of Various Noxious and Environmental Weeds with Picloram Gel Based Herbicides.  Proceedings of the 14 Nsw Weeds Conference. Weed Society of NSW.

Parsons, W.T., & Cuthbertson, E. G. (2001). Noxious weeds of Australia. CSIRO publishing.

PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved 2019 from https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=in&name=Olea~europaea+subsp.~cuspidata

Queensland Government (2016). Weeds of Australia, Biosecurity Queensland edition Fact sheet: Olea europaea L. subsp. cuspidata.  Retrieved 2019 from https://keyserver.lucidcentral.org/weeds/data/media/Html/olea_europaea_subsp._cuspidata.htm

More information

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Control

Successful weed control relies on follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.

Aim to control plants before they fruit.

Physical removal

Hand weeding

Pull or dig out seedlings, removing all of the roots.

Chemical control

Spraying

Spray seedlings or small plants.  Thoroughly cover all of the foliage. African olive re-sprouts from the base if it is burnt or cut down. Re-spray new growth.

Cut stump.

This method can be used for plants up to 10 cm in diameter. Cut the stems/trunk no more than 10 cm above the ground. Apply herbicide within 15 seconds. 

Stem injection

Use stem injection for plants with a stem greater than 10 cm diameter. Drill, say or use an axe to make cuts or holes all the way around the trunk. Inject or apply gel within 15 seconds of cutting.

Basal barking

Use this method for plants with stems up to 5 cm in diameter. Spray or paint herbicide mixed with diesel all the way around the trunk or stem of the plant from ground level to a height of 30 cm. Wet thoroughly.

Herbicide options

See Using herbicides for more information.

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 1 part glyphosate to 50 parts water
Comments: Spray seedlings / coppice shoots.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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PERMIT 9907 Expires 31/03/2025
Glyphosate 360 g/L (Various products)
Rate: 1 part glyphosate per 1.5 parts of water
Comments: Cut stump, stem scrape or injection, saplings or large trees and shrubs.
Withholding period: Nil.
Herbicide group: 9 (previously group M), Inhibition of 5-enolpyruvyl shikimate-3 phosphate synthase (EPSP inhibition)
Resistance risk: Moderate

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Picloram 44.7 g/L + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump application: Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm. Stem inject application for trees: Make a series of cuts 15-20 mm deep around the trunk using an axe or saw. Space cuts evenly with no more than a 20-40 mm gap between them. Apply a 5 mm layer of gel over the lower surface of the cut.
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Triclopyr 600 g/L (Garlon® 600)
Rate: 4.0 L per 60 L diesel
Comments: Basal bark application up to 5 cm basal diameter or cut stump application over 5 cm.
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Biosecurity duty

The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.

Area	Duty
All of NSW	General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable.
Central Tablelands Contain recorded populations across the Central Tablelands region.	Regional Recommended Measure* (for Regional Priority - Containment) Whole of region: Land managers should mitigate the risk of the plant being introduced to their land. Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
Greater Sydney An exclusion zone is established for all lands in the Blue Mountains City Council local government area and lands to the west of the Nepean River in the City of Penrith local government area. The rest of the region is classified as the core infestation area.	Regional Recommended Measure* (for Regional Priority - Containment) Whole of region: Land managers should mitigate the risk of the plant being introduced to their land. Within exclusion zone: Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Notify local control authority if found. Within core infestation area: Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment.
Hunter An exclusion zone is established for all land in the region, except the core infestation which includes parts of: Dungog Local Government Area, Lake Macquarie Local Government Area Maitland Local Government Area, MidCoast Local Government Area, Port Stephens Local Government Area, Singleton Local Government Area.	Regional Recommended Measure* (for Regional Priority - Containment) Entire Hunter Local Land Services region: Land managers should mitigate the risk of the plant being introduced to their land. Exclusion zone: Notify local control authority if found. Land managers should eradicate the plant from the land and keep the land free of the plant. A person should not deal with the plant, where dealings include but are not limited to buying, selling, growing, moving, carrying or releasing the plant. Core infestation: Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
North West	Regional Recommended Measure* (for Regional Priority - Asset Protection) Land managers should mitigate the risk of the plant being introduced to their land. Land managers should mitigate spread of the plant from their land. A person should not buy, sell, move, carry or release the plant into the environment. Land managers should reduce the impact of the plant on assets of high economic, environmental and/or social value.
	*To see the Regional Strategic Weeds Management Plans containing demonstrated outcomes that fulfil the general biosecurity duty for this weed click here

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Reviewed 2023