African boxthorn is a large perennial shrub originally planted in Australia as hedging to provide shelter from wind and barriers to stock movement. The weed is now widespread and found on roadsides, pasture and in native vegetation.
What is African Boxthorn?
African boxthorn is an erect, deep-rooted shrub with spine-tipped, densely tangled twigs. It has a deep and branched root system that can produce sucker shoots if broken.
Leaves are light green, fleshy and oval shaped. Flowers have five petals which are white with purple blotches. Fruit is a round, orange-red berry. Seeds are the main method of reproduction which can germinate at any time of the year, competing with native shrub species. Flowering and fruiting can occur throughout the year but is most abundant in spring/summer.
Where is African boxthorn found?
African boxthorn is widespread in our region and able to grow in a range of climates, habitats and soil types. It can be found around disused buildings, along fences, waterways, roadsides, railway lines, agricultural land and in native vegetation.
What are the impacts of African boxthorn?
The thorny bushes form dense impenetrable thickets, restricting movement of stock, humans and vehicles, and provide harbor for pests such as foxes, rabbits and fruit fly.
African boxthorn competes with desirable pasture plants, restricts native vegetation, and invades watercourses restricting the access to water by animals. Once established, African boxthorn is difficult and expensive to control, often requiring herbicide control or heavy machinery to complete physical removal. Fruit may be toxic to humans and spines can inflict painful injuries.
What is the declared status of African boxthorn?
In the Murraylands and Riverland region, African boxthorn is subject to the following actions:
- Land owners and managers must take reasonable steps to kill plants and prevent their spread.
- African boxthorn must not be sold or traded in any way, including as a contaminant of anything.
- African boxthorn must not be transported on a public road, including as a contaminant of anything.
How can African boxthorn be controlled?
Landholders should assess and monitor areas for new seedlings, particularly under areas where birds perch. Arrivals of stock, machinery and purchases of hay/fodder should also be assessed and monitored to ensure they are free of weed seeds. Once identified, outbreaks of African boxthorn should be treated using recommended measures including follow up treatments until the weed is killed.
Visit the PIRSA website to find out chemical control options and dosing rates specific to African boxthorn.
For more information about identifying or controlling African boxthorn, contact your local district officer from the Murraylands and Riverland Landscape Board.
What to do if you suspect an African boxthorn outbreak
Notify the Murraylands and Riverland Landscape Board if assistance is required. If the plants are actively growing on your land, remove and destroy the plant or treat with a relevant herbicide until the plants are killed.