Boxthorn weeds reduced to skeletons on Yorke Peninsula

Controlling the invasive boxthorn weed might not happen overnight, but Yorke Peninsula landholders have discovered the long-term benefits are worth the wait.

A coordinated control program was launched two years ago on southern Yorke Peninsula to improve productivity on grazing land and reverse the decline in native vegetation caused by the declared weed.

Local landowners, contractors and landscape officers from the Northern and Yorke region spent a week in May 2018 treating boxthorn on road reserves and private property near St Vincent Highway between Warooka and Yorketown. In some areas, the boxthorns were the size of trees and invading paddocks grazed by sheep and cattle and in others, it was strangling remnant native vegetation.

They mainly used the granular herbicide Tebuthiuron, a treatment option that takes about two years to take effect but is cost effective and minimises disturbance to surrounding vegetation and soil.

Olsson’s Pacific Salt Lakes Administrator Tawni Jones said the boxthorn treatment was so effective that previously flourishing boxthorn weeds now looked like skeletons.

“When it dries out a bit and we remove all the skeleton-looking boxthorns, the beautiful nitre bush and other natives that were being suffocated by the boxthorns will really start to thrive,” she said.

“It was really important to us as new land holders in the area to help remove the existing boxthorns and reduce the threat of them spreading. The native flora species inhabiting the

Peesey Lakes are truly beautiful and the land here is so productive. We want to do our part to protect it.”

African Boxthorn (Lycium ferocissimum) is a large spiny shrub that reduces the value of pastoral land and replaces native vegetation, especially in coastal areas and along creek lines.

Its spines can injure stock and limit access to water and pasture and where dense thickets form, it provides harbour for foxes and wild rabbits.

Northern and Yorke Landscape Board Landscape Officer Janet Moore said now is the right time for land holders to strike back against boxthorns on their properties.

“The winter months provide the best opportunity to get the ball rolling with boxthorn control,” she said. “Many treatment methods are most effective while the plants are actively growing and it is ideal to treat them before flowering and setting of seeds, which are easily dispersed by birds and foxes who eat the berries.

“A good starting point is to get in touch with Northern and Yorke Landscape Board staff, who can provide advice about the different control methods. Freestanding boxthorns are best treated with granular herbicide, but where boxthorns are under trees or around vegetation, it’s a good idea to consider spraying or using the cut and swab method.”

For technical advice and support to control boxthorns on your property, please speak to a Landscape Officer at the Northern and Yorke Landscape Board on (08) 8841 3444 or visit our Pest plants webpage.

This boxthorn treatment initiative was supported through levies collected by the Northern and Yorke Landscape Board with funding support provided through the Australian Government’s Agricultural Competitiveness White Paper, the government’s plan for stronger farmers and a stronger economy.