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. It is most common on well drained soils of the western slopes and plains. It was brought to Australia from South Africa in the mid-1800s as a hedge plant. It 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. It can grow on all soil types, though it grows best on well-drained, sandier soils along dry creek beds. It can be found:

• 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, 2017-2021)
  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 requires 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 tackle 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. 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.

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

Pushing out the plants is the cheapest way to control mature thickets. Remove as many of the roots as possible and burn. Removal of the roots is much easier and more effective when the soil is moist.

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

Herbicides can make the plants lose their leaves and appear dead. New leaves appear and the plant begins to recover. This may happen several times before the plant dies.

Foliar spray

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.

Foliar spraying is the most common method of control. 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.

For large bushes it is very costly and difficult to obtain good coverage with the herbicide. Consider bulldozing thickets of large bushes and spraying the regrowth.

Basal bark treatment

When: Year-round

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

Use basal barking in environmentally sensitive locations. It’s best for small bushes with stem diameters up to 5 cm. Cover the base of every stem to a height of 30 to 40 cm above the soil surface.

Cut stump treatment

When: Year-round

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

This technique is also appropriate for small infestations in environmentally sensitive locations. It’‘s best for large plants with stem diameters greater than 5 cm.

Cut each stem off 15 cm above the soil surface. Cover the cut surface with herbicide within 30 seconds. If herbicide is not applied immediately the plant will heal and the herbicide won't work.

Root application

When: Year-round

Follow-up: Revegetate when the residual period is over.

Take great care when using this technique. This method uses a residual herbicide that will remain active in the soil for some time. Many desirable trees e.g. eucalyptus, are susceptible to the residual herbicides. Do not use this method within a distance of at least twice the height of adjacent desirable trees or shrubs.

Apply the residual herbicide:

• directly under the plant, towards the edge of the canopy
• under the soil to stop degradation by sunlight and rain washing the herbicide away
• when the soil is moist, usually in spring or autumn.

The residual effect may also control seedling regrowth for some time after application.

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 injection or stem scrape application
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
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: Handgun application for small bushes only. Spray soil to drip line. Thorough coverage is essential. Spray prior to budburst.
Withholding period: 1-8 weeks (see label).
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Glyphosate 360 g/L (Various products)
Rate: 0.7–1.0 L per 100 L
Comments: Handgun application, with low rate on young bushes, high water rate on mature bushes. Do not spray in hot dry summer periods.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

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Glyphosate 360 g/L with Metsulfuron-methyl 600 g/kg (Various products)
Rate: 10 g metsulfuron plus 1 litre glyphosate in 100 L of water
Comments: Always add non-ionic surfactant to the spray mix. Apply to actively growing weeds.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate

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Picloram 44.7 g/kg + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Tebuthiuron 200 g/kg (Graslan®)
Rate: 2 g per m2
Comments: Hand application (granules). Estimate the area within 30 cm beyond the drip line of the target plant and calculate the amount of Graslan required. Do not apply near desirable trees.
Withholding period: Nil.
Herbicide group: C, Inhibitors of photosynthesis at photosystem II (PS II 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
Comments: Basal bark application up to 5 cm basal diameter. Cut stump application for over 5 cm diameter.
Withholding period: Nil
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate

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Triclopyr 300 g/L + Picloram 100 g/L (Grazon® DS)
Rate: 500 mL per 100 L of water
Comments: Handgun application for when bushes have good leaf cover, growth and no leaf fall. Only apply to plants less than 2 m tall.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
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 for over 5 cm diameter.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
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 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 dealings Must not be imported into the State or sold
Central Tablelands	Regional Recommended Measure* Land managers should mitigate the risk of new weeds being introduced to their land. Land managers should mitigate spread from their land. The plant should not be bought, sold, grown, carried or released into the environment. Protect primary production lands that are free of African boxthorn
North West	Regional Recommended Measure* Land managers should mitigate the risk of new weeds being introduced to their land. Land managers should mitigate spread from their land. Land managers reduce impacts from the plant on priority assets.
Western	Regional Recommended Measure* Land managers mitigate the risk of the plant spreading from their land. Land managers reduce impact of plant on priority assets (riparian areas and floodplains).
	*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 2020