28 alternatives to plant after removing borer beetle infested trees

Staff Reporter|Published 1 year ago

On 10 March 2023, Cape Town Deputy Mayor Eddie Andrews planted an Assegai tree along the Liesbeek River in Mowbray. The City is encouraging residents to participate in a voluntary tree replacement initiative as authorities fight the Polyphagous Shot Hole Borer (PSHB) infestation that is posing a serious threat to Cape Town’s urban forest.

Cape Town - The City of Cape Town has issued a list of 28 recommended trees for residents who want to replace trees on their properties that are infested with the invasive borer beetle.

Planting an indigenous tree or non-invasive exotic tree, suitable to the local climate and the specific site, will assist in mitigating the impact of the Polyphagous Shot Hole Borer (PSHB) beetle on Cape Town’s urban forest.

To date, the borer beetle has been sighted in the Helderberg area, and most recently in Newlands, Rondebosch, Mowbray, Claremont, Kenilworth and in Observatory along the Liesbeek River.

The list of recommended trees includes indigenous and mostly locally indigenous species, that are not reproductive host trees, meaning to date, the PSHB has not been sighted in these trees. The non-invasive exotic trees on the list are allowed in urban areas, such as residential gardens.

Mayco member for Spatial Planning and Environment, Eddie Andrews, said: “These are the trees that residents can plant on their private properties to replace the PSHB-infested trees that must be removed to stop the spread of the pest to other trees and areas. We will update the list of recommended trees continuously as we learn more about the PSHB and the trees it targets.

“If we plant trees to replace those we lose in coming months and years, we can limit the impact of this devastating pest on Cape Town’s urban forest,” said Andrews.

The City’s Tree Best Practice guideline provides more information about trees suitable to Cape Town’s climate, and is available on the City’s website at: https://bit.ly/3GepNzC.

Last month the City started removing infested trees from public land along the Liesbeek River corridor, near the N2 highway and Liesbeek Park Way. To date, 40 trees have been removed with chainsaws and wood chipping machines, and the beetle-infested biomass transported to an appropriate site for incineration.

Cutting down of a poplar tree on Liesbeeck Parkway . The tree has been infected by the shot borer beetle.

What to look out for and symptoms of infested trees:

*Branch dieback – cracks on the branch, discoloured leaves, dry and leafless branches, branch break-off revealing webs of galleries filled with black fungus.

*Gumming – blobs of goo coming out of the bark; oozing of liquid and gum from the beetle holes.

*Entry and exit holes – very small holes on the bark of the tree, the size of a sesame seed (2mm); shotgun-like scars developing around the holes.

*Staining – brown or dark stains on the bark of the tree.

Report PSHB beetle sightings online, at www.capetown.gov.za/InvasiveSpecies, or call the City of Cape Town’s Invasive Species Unit on 021 444 2357, Monday to Friday, from 7:30am to 4pm or send an email to: invasive.species@capetown.gov.za.

Cape Times