Stellenbosch Municipality is working with a local non-profit organisation (NPO), to curb the spread of the Polyphagous Shot-Hole Borer (PSHB) infestation that has plagued Stellenbosch’s oak trees.
The town’s iconic oak trees have been infested by the invasive beetle “for about three years”, said Dirk Bellstedt, an emeritus professor at Stellenbosch University’s department of biochemistry.
The beetles often start to infest trees undetected at first. This is because, “the PSHB beetle has to multiply and then two to three years down the line, it really starts viciously having an effect and that’s what we’re seeing [now],” said Bellstedt.
He explained that the beetle inhabits the tree and produces a fungus, called Fusarium euwallaceae, which is crucial to the beetle’s survival. This fungus is the beetle’s main food source and over time, kills the trees.
“The fungus blocks the water-transporting vessels of the tree,” said Bellstedt. “With the conditions as we have it at the moment with the high heat, the trees don’t get enough water to their high branches and they die off,” he added.
Apart from being unsightly, the dead trees have posed a risk to residents of the town. According to Bellstedt, the branches may break off and trees could collapse at any time. This can cause personal injury or property damage. On 9 March, a video was posted on TikTok that showed an oak tree collapsing in Plein Street. The video was also later reposted by The Feed CPT on Instagram.
The stump of a large oak tree that was cut down, after it collapsed and caused property damage on 9 March in Plein Street. PHOTO: Dylan Lackay
To combat this, the municipality has partnered with the Stellenbosch Trail Fund (STF), a local NPO, that specialised in maintaining the town’s natural resources, along with some residents of the town, to launch a tree planting project that aimed to curb the spread of the infestation. The project will consist of cutting down and removing the already dead oak trees and planting new ones.
Francé Beyers, a local Stellenbosch resident, who is leading the project with STF, said that, alongside the municipality, they are looking to plant different oak tree variations, such as the Turkish oak (Quercus cerris), as opposed to the European oak, which were infested. According to Bellstedt, these Turkish oak trees are not susceptible to the infestation and will not be affected once planted.
One of the many large oak trees that fill up the streets of Stellenbosch, providing shade and beauty to the town’s residents. PHOTO: Dylan Lackay
The municipality’s role in the project was to identify dead trees, get approval for their removal, and hire contractors to conduct the removals. STF, because of its NPO status, served as the financial vehicle through which donations to the project flow. Beyers’ responsibility was to approach local businesses to source funding and donations for the project.
According to Ernst Gouws, STF’s representative for the project, they had the municipality’s full support and the fundraising for the project was going well. The project team’s objective is to plant at least 30 new oak trees in 2026.
“I am confident that we’ll be able to raise all the funds to be able to plant all the trees we want to over the winter,” said Gouws.
Beyers said that they were looking to plant two trees in Plein Street, on Friday, 20 March. Stuart Grobbelaar, Stellenbosch Municipality’s communications manager, also confirmed that for the next two weeks, tree-felling operations would be taking place along Plein and Andringa streets.
“While the municipality recognises the strong heritage value of many of Stellenbosch’s trees, the safe removal of trees that are infested, diseased or structurally compromised is sometimes necessary,” said Grobbelaar. “Removing affected trees helps prevent the spread of pests and diseases to surrounding trees and protects the broader urban environment,” he added.
Ryneveld Street, one of the most well known streets in Stellenbosch, lined with the famous oak trees. PHOTO: Dylan Lackay
Currently, the project is seeking public donations from residents of the town.