Council is preparing to replace a number of plants in the cemetery's Memorial Rose Garden in the new year, with a number of rose bushes currently in decline.
Rose bushes are dead or dying in some patches of the garden, while plants in other areas are still in good health.
Council's Director Infrastructure and Environment, Codie Howard, said staff were currently investigating the issue.
"We're not sure what has caused the plants to struggle in some parts of the garden, it's quite odd and not something we've seen before in the cemetery," he said.
"We just want to let the public know we're aware of the issue, and we understand the importance of the garden to local residents.
"We'll try and save all the rose bushes we can, and those that don't make it through the summer will be replaced when planting season comes around again next year."
