Tree transplant demonstration project


Case Study: City Renewal Authority tree transplanting in Dickson and Lyneham

Last updated: 18  May 2020

Overview

In November 2019, 11 mature trees were transplanted to Dickson and Lyneham by a mature tree transplant specialist as part of the City Renewal Authority’s (Authority’s) first tree transplanting project.

In partnership with Transport Canberra and City Services, Environment, Planning and Sustainable Development and the Suburban Land Agency, this project demonstrates how trees can be protected as part of urban renewal and development.

The mature trees were transplanted into two new locations:

Why transplantation?

Trees on their former Dickson Section 72 site
Trees on their former Dickson Section 72 site

The Authority coordinates urban renewal in the city precinct that is design-led, people focused and socially and environmentally sustainable. All development in the city precinct is assessed using ten principles for best practice urban design. This tree transplanting project demonstrated a way to retain mature trees as part of development.

Mature trees provide multiple benefits to a place, including amenity and shade for the surrounding area, improving soil health and increasing water permeability into the soil. This all helps to address the impacts of urban heat in summer.

The Authority advocates for designing around a mature tree wherever possible, however sometimes this is not possible. This is why we wanted to demonstrate that the transplanting of large trees is an alternative solution.

The transplantation

Tree preparation and root pruning, May 2019

Trees on their former Dickson Section 72 site
Root pruning and feeding in May 2019

In early 2019, the Authority requested conditions be placed on a Dickson development application to ensure any viable trees were considered for transplanting from the site to a suitable alternative site. The trees to be transplanted were located on a Section 72 development site in Dickson and estimated to be approximately 20 years old.

There were 10 trees deemed suitable to be part of this cross-government tree transplanting demonstration project, with a spare tree also prepared for transplanting.

The roots of the trees were pruned by specialist arborists from Arbor Centre, to manage the root zone and were wrapped in a soil improvement mix to help stimulate new root growth. The rootball was backfilled with soil, and the trees were watered for five months.

Tree removal and transplanting to a new home, November 2019

Relocation of the trees involved carefully boxing up the trees where they were growing and moving them by truck.

trees loaded onto a truck

Transporting trees to new homes, Nov 2019

They were then craned into their new homes for planting.

craning trees into place

Trees craned into their new homes, Nov 2019

Aftercare program and transplantation outcomes

In the tree’s new locations, smart soil sensors were installed to regularly monitor the soil moisture to help the trees remain healthy and adapt to their new environment. Regular inspections, a specific watering regime and a monthly feeding program using a liquid fertiliser was also undertaken.

Within the first six months of the trees being transplanted, challenging weather conditions were experienced in Canberra. The 2019/20 summer presented unprecedented weather including hot dry winds, no rain and bushfires in surrounding areas. This was followed by hail and heavy storm events in February and March 2020. Out of the 11 trees, 10 survived the transplantation and the difficult conditions.

The larger and more mature, Manchurian Pear trees at Dickson showed more dramatic signs of initial ‘transplant shock,’ compared to the trees at Lyneham. As a natural response to the long hot dry spells and unpredictable weather, the Dickson trees lost some of their leaves ahead of autumn and both sites saw autumn colour on leaves before it was expected. This was not uncommon for many trees across Canberra as a response to the unpredictable weather in early 2020.

new buds forming on a pyrus tree
New buds forming on the pyrus trees

In March 2020, root and tree health inspections were undertaken by the specialist arborist which identified that 10 trees were in good health. The inspection revealed that the younger and smaller, spare tree (a Chinese Pistachio at Lyneham) did not survive. This is likely due to the tree being shifted too closely to bud burst and the leaves still being juvenile (not hardened off fully) compared to the other ten trees. Unfortunately, the leaves turned brown within the first three months of the transplant and it did not recover its health. The tree will be removed, and a new Chinese Pistachio tree will be planted in that space.

For the remaining healthy trees, additional draining was recommended to maintain the tree root health that was being compromised by site waterlogging. This will involve the installation of drainage channels around the beds so that additional storm and surface water is redirected away from the root ball of the Manchurian Pear trees. A healthy root zone is critical for a tree to reach its full potential.

trees located at the Dickson pool forecourtbike rider on footpath near transplanted trees in Lyneham

Manchurian Pear Trees in Dickson, December 2019 Chinese Pistachio Trees in Lyneham, April 2020

Care for these trees is continuing to ensure they continue to thrive in their new locations. Overall, this project has successfully saved 10 trees from demolition on a development site and provided a demonstration that mature trees can be protected and relocated in Canberra, if a development project cannot design around an existing mature tree.

Retaining or transplanting mature trees has many environmental, social and economic benefits for the community, including immediate shade and cooling to key locations, providing homes and shelter to existing wildlife, and a level of amenity that would take younger trees, years of growth to equal.

Before trees were transplanted, LynehamTransplanted trees in Lyneham

Before and after Chinese Pistachio trees were transplanted, Lyneham 2019

Community interest

The Authority has received overwhelmingly positive feedback about this project. The trees have provided an improved outlook in the spaces in both Dickson and Lyneham.

The trees in Dickson have formed part of a larger upgrade to the Dickson Pool Forecourt. As part of that project, an evaluation of the upgrades was undertaken through surveys with the community. This revealed that the most popular aspect of the upgrade was the trees and gardens and how they had transformed the space into a shadier and more inviting place over summer when the pool was being used.

If you would like to find out more details about this project, please contact cityrenewal@act.gov.au.

This project is a cross government collaborative between City Renewal Authority, Environment Planning and Sustainable Development, Transport Canberra and City Services and Suburban Land Agency.