The City of Cape Town has released a list of 28 recommended trees for residents who want to replace trees on their properties that have been infested with the invasive Polyphagous Shot Hole Borer (PSHB).
Planting an indigenous tree or a non-invasive exotic tree suitable for our climate and location will help to mitigate the beetle’s impact on Cape Town’s urban forest.
Evidence of infestation by the borer beetle has been found most recently in Newlands, Rondebosch, Mowbray, Claremont, Kenilworth and Observatory along the Liesbeek River.
Also read: Residents encouraged to participate in the City’s tree replacement initiative
The list of recommended trees includes indigenous and mostly locally indigenous species that are not reproductive host trees, which means the PSHB has not been seen in these trees to date.
The exotic trees on the list that are non-invasive are permitted in urban areas, such as residential gardens.
‘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,’ said the City’s Deputy Mayor and Mayoral Committee Member for Spatial Planning and Environment Alderman Eddie Andrews. ‘We will update the list of recommended trees continuously as we learn more about the PSHB and the trees it targets. I encourage residents to go online and use the list, which includes the trees’ scientific and common names.’
He added, ‘If we plant trees to replace those we lose in the coming months and years, we can limit the impact of this devastating pest on Cape Town’s urban forest.’
The City began removing infested trees from public land along the Liesbeek River corridor, near the N2 highway and Liesbeek Park Way, last month.
To date, 40 trees have been felled using chainsaws and wood-chipping machines, and the beetle-infested biomass has been transported to a suitable incineration site.
Dos and don’ts:
- Do not move any plant or tree parts from places where PSHB has been found, such as Somerset West, Newlands, Kenilworth, Mowbray, Rondebosch, Observatory and Wynberg.
- When handling plant material, inspect the tree for PSHB symptoms.
- Clean gardening tools and other tools before and after use, and clean and sanitize vehicles that move green waste.
- Transport green waste in closed and sealed bags or cover the back with a tarp.
- Avoid routes passing through areas with PSHB-infested trees.
- Buy firewood where you are going to use it.
- Don’t fall for fake remedies. There is no known cure as of yet.
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.
Important: Infested trees must be chipped on site and may not be removed from the property, as the removal of the chipped wood will spread the pest to other areas.
How to report PSHB beetle sightings
- Online, at: www.capetown.gov.za/InvasiveSpecies
- Call the City of Cape Town’s Invasive Species Unit at 021 444 2357.
- Send an email to: [email protected].
What to do with infested trees:
- Chip the tree, place the infested material in refuse bags, seal it and put these in direct sunlight for at least six weeks.
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- Dump the chips in your compost heap, as the heat buildup will kill the beetle.
- Burn infected wood at appropriate incineration facilities.
- Seek assistance from trained and equipped service providers with sound knowledge of PSHB.
- Do not move plant material or firewood outside of areas where PSHB has been confirmed to be present.
- Do not transport any form of green waste in open vehicles; cover it with sail covers even if no PSHB has been identified as such green waste.
- Clean tools and equipment are used to trim, cut and prune plants.
The City said that it would do its best to respond to a sighting report within 10 business days. However, the response time will depend on the number of sightings reported.
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