Q+A: Caring for Australia’s oldest olive tree at Wesley Place


We sat down with Greenwood Consulting arborist, Dan van Kollenburg to find out more about what it takes to care for Australia’s oldest living Olive tree – here at the heart of our transformative Wesley Place precinct in the Melbourne CBD. 

How did you come to care for this special tree?

In 2016, I was asked to assess the trees at the new site for Wesley Place. Two in particular were deemed especially significant to the heritage of the site, an old elm and a 140-year-old olive tree.

Both trees are very significant for Melbourne, so my job is to help the engineers, architects and builders to effectively work around these historic trees and ensure they’re in the best health possible for generations to come.

What condition is the tree in?  

Before Charter Hall took over the site, the tree was growing in pretty harsh conditions with highly-compacted imported soils restricting areas for root growth. So I was brought on to ensure that the tree’s health improved and remained a priority throughout the development.

For example, when the leaves looked yellow - a sign of nutrient deficiency or water stress - I called a meeting onsite. We then removed the bitumen around the tree, installed its own irrigation system and added a thick layer of mulch. Now, the tree is in much better condition than it was before the commencement of development works and has even added height and produced a significant quantity of fruit over the past few seasons!

Did operations on the Wesley Place site need to adapt at all to ensure the health of the olive tree?

Yes.  Over the years, we’ve worked closely in partnership with Charter Hall, Lendlease, Cox Architecture, Oculus, and Armitage Jones to determine the best way of operating onsite in order to best preserve the Olive tree. Despite the complexity of some of my recommendations, all stakeholders have been very supportive and agile.

For example, non-destructive hydro excavation is preferred near the tree and suspended paving slabs have been used to avoid root damage and preserve the soil volume available to the tree. We also created structural and tree protection zones to limit certain construction activity from getting too close. Fencing has been installed around the tree to prevent works from encroaching into the Tree Protection Zone, and I inspect the trees every fortnight.

What do you love about your job?

I spend about 60 percent of my day looking at trees, and 40 per cent writing about them. So I don’t think you could do my job without a  real passion for them. I also love spending time outside - not many people get to be in nature for a living, so I feel lucky every day. And I’m fascinated by the details we often miss, like fungus and microbats. Trees are wonderful things.