Caring for one of our oldest residents

By Isabelle Harris

Amid all the current stresses of COVID-19, arborist Dan Kollenburg is continuing to care for Australia’s oldest olive tree, which is forming part of a new development at Wesley Place in the CBD. 

Mr Kollenburg studied arboriculture at Burnley College, which is part of the University of Melbourne, and has previously worked with the City Melbourne (among other councils) on a vast array of conservation, risk assessment and data projects.

Since developer Charter Hall began development of its Wesley Place project on Lonsdale St in 2016, the arborist has been checking in on a 180-year-old olive tree at the site fortnightly to ensure that its health is not impacted by construction work and its growth is monitored.

He said the project’s engineers and designers had ensured his recommendations were implemented as part of the development, with the tree to be central to a new green space for CBD residents and workers to enjoy adjacent to Charter Hall’s new commercial office buildings and Wesley Church. 

While noting that working in a confined space made addressing the tree’s specific needs more difficult, he said the results of his specialist care were showing, with the tree’s increased health status having led to significant fruit development over the past few seasons. 

“With older trees, you have to tread more lightly around them,” he said.

He told CBD News that part of his responsibility in protecting the tree included ensuring that there was overall very little excavation within the tree protection zone during construction, while using hydro-excavation techniques to investigate root growth. He said he had also provided important recommendations around the thickness of paving around the tree.

When leaves looked a little yellow in 2017 (usually a sign of nutrient stress), he installed an irrigation system, mulch and protection fencing around the tree, which boosted its health status.

If branches need to be pruned, he said he organised specialist tree climbers to come in.

Regional development director at Charter Hall Simon Stockfeld said the olive tree and the surrounding greenery were major influences of the space’s redesign. 

“The heritage-listed olive tree itself has been a vital part of our work to restore the legacies of those who have been before us, but also leave a new legacy for future generations to reflect on,” he said. 

The tree was previously surrounded by bitumen in a carpark close to the Wesley Church on Lonsdale St. 

While the olive tree is of special importance to the project, Mr Kollenburg said the same treatment should be given to every significant tree.

“I think our heritage trees should be given the same protections as heritage buildings,” he said •