African boxthorn (Lycium ferocissimum)

African boxthorn is a thorny shrub with red berries and purple flowers. It forms impenetrable thickets and is poisonous to people.

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How does this weed affect you?

African boxthorn:

• has large thorns which can injure livestock
• forms impenetrable, spiny thickets that block access for vehicles, livestock and people
• invades pastures, roadsides, reserves, remnant bushland and waterways
• provides shelter and food for pest animals including foxes, rabbits and starlings
• prevents livestock from accessing shade
• is poisonous to humans
• is a host for pest insects including fruit fly, tomato fly and house fly.

Human poisoning

African boxthorn berries, leaves, stems and roots are toxic to humans. Symptoms include: nausea, vomiting, breathing difficulties and unconsciousness. Eating plant parts will cause discomfort and irritation but is not usually life-threatening.

What to do if a person is poisoned:

• If the patient is unconscious, unresponsive or having difficulty breathing dial 000 or get to the emergency section of a hospital immediately.
• If the patient is conscious and responsive call the Poisons Information Centre on 13 11 26 or your doctor.
• If going to a hospital take a piece of the plant for identification.

What does it look like?

African boxthorn is a woody, thorny shrub that can grow up to 5 m high and 3 m wide. Young plants grow quickly. Plants sometimes drop their leaves and appear dead during drought or in winter.

Leaves are:

• oval with a rounded tip
• smooth and fleshy
• 10-40 mm long
• bright green
• in clusters along the branchlets
• larger and more succulent on regrowth from damaged roots.

Flowers are:

• white to purple with 5 petals
• 1 cm in diameter
• tubular at the base with purple or pale blue markings
• fragrant
• single or in pairs in the leaf axils
• usually present spring and summer but can occur year round.

Fruit are:

• round berries
• green when young 
• orange-red when ripe
• 5-10 mm in diameter containing 20-70 seeds
• usually present in autumn but can be present year round.

Seeds are:

• light brown to yellow
• irregular-shaped
• flattened
• smooth with small, raised dots
• 2.5 mm long and 1.5 mm wide.

Stems are:

• rigid
• very branched
• thorny with thorns up to 15 cm long on the main stem and stout thorns on the ends of branches. 

Roots

African boxthorn has an extensive, deep, branched taproot that will sucker and produce new growth when broken. Roots on seedlings grow rapidly allowing them to compete with other plants.

Where is it found?

African boxthorn grows across NSW and is most common on well drained soils of the western slopes and plains. This tree was brought to Australia from South Africa in the mid-1800s as a hedge plant and has spread from around old homesteads and urban areas.

What type of environment does it grow in?

African boxthorn is drought tolerant and grows in temperate, subtropical and semi-arid regions. Trees can grow on all soil types, though they grow best on well-drained, sandier soils along dry creek beds. African boxthorn grows:

• in woodlands
• in rangelands and uncultivated pastures
• in open coastal areas
• along roadsides 
• along waterways.

Maps and records

• Recorded presence of African boxthorn during property inspections (Map: Biosecurity Information System - Weeds, 2017-2024)
  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

African boxthorn plants are at least two years old before they flower and produce fruit. Seeds can germinate at any time of the year if there is adequate moisture and warmth.

Seed is mainly spread by animals. Birds and foxes eat the fruit and spread the seed and plants are often found beneath bird perches such as trees, poles and powerlines. Seeds can also be spread in contaminated mud or agricultural produce.

By plant parts

The extensive, branched taproot will sucker and produce new growth if broken. 

References

Department of Primary Industries, Water and Environment, Tasmania (2002). African boxthorn (Lycium ferocissimum), DPIWE Information sheet. Available at www.dpiwe.tas.gov.au

Parsons, W.T. and Cuthbertson, E.G. (2001). Noxious weeds of Australia, second edn, CSIRO Publishing, Collingwood, Melbourne.

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.

To manage African boxthorn:

• treat mature plants and follow-up to suppress regrowth
• kill young plants before they are two years old to prevent seed set
• follow-up until African boxthorn is eradicated
• promote vigorous perennial pastures to resist invasion.

Pasture management 

Vigorous native perennial pastures compete with African boxthorn seedlings. Establish pastures as soon as possible after weed removal. Consult an agronomist for advice on pasture establishment and management.

Physical removal

By machine

When: Year-round. It’s easier to get the roots out of the soil after rain when the soil is moist.

Pushing out the plants may be the cheapest way to control mature thickets that are not mixed with desirable vegetation. Remove as many of the roots as possible and burn. It is important to destroy all plant material after physical removal because:

• Dead branches still pose a problem because of their thorns and they can harbor pest animals.
• Unripe fruit on cut branches can still ripen and produce seed.
• Broken root fragments may sucker and produce new growth.

An infestation might be valuable habitat for native fauna. In this case, use a staged control program. Gradually replace the African boxthorn with suitable native species.

Cultivation

When: After physical removal of plants.

Follow-up: When regrowth appears and in autumn or when new seedlings appear.

Deep rip the soil to bring remaining root fragments to the surface. Rake and burn the root pieces. Cultivation may cause deeper root fragments to shoot. Check and treat above ground regrowth.

Chemical control

Follow up applications of herbicide may be necessary. Check treated plants for regrowth.

Foliar spraying

When: Usually in spring, after rain when the plant is actively growing. 

Follow-up: In autumn when new seedlings appear. Use other methods to control regrowth or wait until regrowth is over 50 cm high (approximately 18 months old) to repeat spraying. Spray the whole bush when the plant is actively growing. This will vary depending on the location and rainfall.

Do not spray during hot, dry periods or when the plant is stressed from drought, waterlogging, or cold. Foliar sprays are more effective when plants have more leaves.

Spraying is best for plants under 2 m tall. Spraying large bushes is expensive and obtaining good coverage with the herbicide is difficult. Consider bulldozing thickets of large bushes and spraying the regrowth.

Soil spraying

When: Before bud burst (when plants start growing from their buds after being dormant).

This method is for small plants that are not close to desirable plants. Thoroughly cover the soil from the trunk to the dripline of each plant.

Basal bark treatment

When: Year-round

Follow-up: If regrowth appears and in autumn when new seedlings emerge.

Use basal barking for plants with stems up to 5 cm in diameter at the base.  Liberally spray the bark all the way around the stem from ground level to 30 cm high, wetting thoroughly to the point of runoff.

Cut stump treatment

When: Year-round

Follow-up: When regrowth appears and in autumn when new seedlings emerge.

This technique is suitable when there are desirable plants close to the boxthorns. Cut each stem off less than 15 cm above the soil surface. Cover the cut surface with herbicide within 15 seconds. If herbicide is not applied immediately the plant will heal and the herbicide won't kill the plants.

Stem injection

For large mature plants, drill holes all the way around the lower stem of the plant using a 10 mm drill bit. Fill the holes with herbicide within 15 seconds. Alternatively make a series of cuts 15-20 mm deep around the trunk using an axe or saw. Space cuts evenly with a minimal gap between them. Fill each cut with the herbicide mix within 15 seconds of making the cut or hole.

Granular herbicide soil application

Estimate the area within 30 cm beyond the drip zone (area under the canopy) of each tree or group of trees. Calculate the amount of herbicide required to cover area to be treated. Distribute the required dose uniformly over the soil within this area. 

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 1.5 parts water
Comments: Stem inject or stem scrape application.
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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2,4-D 300 g/L + Picloram 75 g/L (Tordon® 75-D)
Rate: 1.3 L per 100 L of water
Comments: Spray soil to drip line. Thorough soil coverage is essential. Spray prior to budburst. Treat small plants only.
Withholding period: Do not graze or cut crops (except sugar cane 8 weeks) or pastures for stock food for 7 days after application.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Glyphosate 360 g/L (Various products)
Rate: 0.7–1.0 L per 100 L
Comments: Spray the foliage with low rate on young bushes and high water rate on mature bushes. Do not spray in hot dry summer periods.
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 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L (Grazon Extra®)
Rate: 500 mL per 100 L of water
Comments: Spray plants less than 2 m tall when bushes have good leaf cover, growth and no leaf fall.
Withholding period: Where product is used to control woody weeds in pastures there is a restriction of 12 weeks for use of treated pastures for making hay and silage; using hay or other plant material for compost, mulch or mushroom substrate; or using animal waste from animals grazing on treated pastures for compost, mulching, or spreading on pasture/crops.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
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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Tebuthiuron 200 g/kg (Various products)
Rate: 2 g per m2
Comments: Estimate the area within 30 cm beyond the drip line of tree or group of trees. Calculate the amount of herbicide required and distribute onto the soil evenly. Do not apply near desirable trees.
Withholding period: Nil.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate

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Triclopyr 240 g/L + Picloram 120 g/L (Access™ )
Rate: 1.0 L per 60 L of diesel (or biodiesel such as Biosafe).
Comments: Basal bark application for plants with stems up to 5 cm diameter at the base. Cut stump application can be used for plants with stems up to and in excess of 5 cm diameter at the base. Treat all stems on multi-stem plants. See label for information about biodiesel.
Withholding period: Nil
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate

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Triclopyr 300 g/L + Picloram 100 g/L (Various products)
Rate: 500 mL per 100 L of water
Comments: Spray when bushes have good leaf cover and no leaf fall. Only apply to plants less than 2 m tall.
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: 2.0 L per 60 L of diesel
Comments: Basal bark application up to 5 cm basal diameter. Cut stump application plants is suitable for a range of sizes including those over 5 cm diameter.
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.
All of NSW	Prohibition on certain dealings Must not be imported into the state, sold, bartered, exchanged or offered for sale.
Central Tablelands	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.
Hunter An exclusion zone is established for all land in the region, except the core infestation which includes parts of: Muswellbrook Local Government Area, Upper Hunter 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.
Murray	Regional Recommended Measure* (for Regional Priority - Asset Protection) 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.
Western	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 2024