10 Year Tree Canopy Achieved in 5 Years

10-YEAR TREE CANOPY GROWTH ACHIEVED IN 5 YEARS

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LAMAN STREET

Connected tree canopy in less than 10 years

Laman street, in the heart of Newcastle, Australia, is known for its majestic avenue of fig and jacaranda trees that have grown to meet in the middle and create a stunning continuous canopy overhead. The trees are a host to a variety of native bird species; offer a cool, shady respite for residents and visitors atop the civic park stairs and a fittingly picture-perfect entrance to the Newcastle Art Gallery.

However, the story of the Laman Street fig trees is one of great controversy and while their impressive size has the appearance of them having been there, ‘forever’, they were planted only 10 years ago+.

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2014
1 year growth
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2018
5 year growth

PROJECT DETAILS

Location

Laman Street, Newcastle, New South Wales, Australia

Planting

2013

Council

City of Newcastle

Tree Species

Ficus microcarpa* and Jacaranda mimosifolia

Number of trees

10 ficus and two jacaranda

Challenge

Cohabitation of giant fig trees with modern infrastructure

*Ficus microcarpa is a tropical or subtropical tree native to China, Asia and Australia where it’s often planted for ornamental purposes and shading. In Australia’s climate it grows to around 12m in height with a crown of equal spread.
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2023
10 year growth

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How fig trees divided a city

In 1931 well-intentioned city planners planted a series of Hills Weeping fig trees along Laman Street, to improve the leafiness of Newcastle civic centre, a town built around industry and mining, that had been left bereft of trees.

Fast forward several decades later to the early 2000’s, the figs had reached maturity and were now sharing space with asphalt roads, concrete pavement, kerbs, gutters and underground utilities. Concerns arose about the structural integrity of some of the trees and Newcastle City Council initiated plans to remove some of the trees citing safety concerns, as there were fears branches could fall and cause harm.

However, over the decades, the fig trees had created an iconic streetscape, often referred to as the town’s ‘green cathedral’ for its lush interlocking canopy in close proximity to a number of historic churches in Newcastle. So, when Council proposed to remove the figs it sparked significant opposition from local residents, environmental groups, and community activists. They argued for the preservation of the trees, to preserve their amenity, cultural, historical, and environmental importance.

In response, the Council commissioned an independent investigation into the condition of the trees, and the safety risk they posed. The trees were found to have too few large structural roots resulting in an almost linear root plate. Planted too close to the kerb, it acted as a pivot point under wind load adding extra stress on the root systems which were already vulnerable to extreme weather events. Ultimately, the study found the trees were highly unstable and that they posed a significant health and safety risk.

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Why had the fig trees become unstable?

Their instability was due to the method in which they had been planted, coupled with a lack of knowledge of their growth patterns, compounded by the efects of encroaching modern infrastructure.

20240716111712 1 CitygreenThe trees were planted in standard root-ball tree pits and had outgrown the space available to them. Unable to sustain the large, healthy root systems needed to support their immense canopies, their planting had become an entombment. They were slowly dying, their limbs falling off as precursor to a ticking time-bomb. And that bomb went off in 2007 when the catastrophic Pasha Bulka storm hit Newcastle and four of the fig trees came crashing down.

Still, the controversy around removing the trees continued, leading to legal battles and extensive public debate until 2011, when, after years of dispute, 10 of the fig trees were felled in the interest of public safety.

The attachment the community had developed for the Laman Street fig trees motivated Council to explore the possibility of restoring new fig trees to the street but in way that would ensure peaceful cohabitation with the hardscape and underground infrastructure in the area.

After discussions with Citygreen, their expertise in growing healthy trees in challenging urban environments convinced Council the seemingly impossible, was in fact achievable.

“It would have been much easier to replace the Hills Weeping fig trees with a variety of alternative species, better suited to urban environments, but that wouldhave marked a sad end of the trees planted almost a hundred years ago,” explains Catherine Atkinson, Head of Projects, at Citygreen. “However we were delighted the City of Newcastle wanted to honour the legacy of the original figs and so we devised a solution for replacing them with a species as closely related to the original as possible.”

THE

SOLUTION

“Fig trees as a species are notorious for pavement heave which ruins the value of the infrastructure. But trees should be seen in quite the opposite way - as value adding.”

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Figs are naturally surface rooting and this is often a problem for urban environments where pavement heave is prevalent.

“Fig trees as a species are notorious for pavement heave which ruins the value of the infrastructure. But trees should be seen in quite the opposite way - as value adding. If chosen and planted correctly, trees can thrive in urban areas offering a myriad of benefits such as improving air quality, regulating temperature through shading and cooling, encouraging biodiversity and improving physical and mental health,” says Atkinson.

Citygreen’s structural soil vault system solved the Laman Street fig tree problem by providing all the space their roots needed to grow, but in a directed, managed way which avoids damage to infrastructure. The roots spread into the vaulted spaces allowing them to develop as stable and healthy root systems that are more resilient under climate stress.

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The open matrix design of the Citygreen structural soil vaults were filled with a specified soil mix designed to deliver the highly aerated soil conditions figs prefer, providing optimal soil conditions for growth and to establish structural root systems.

“The advanced soil vault systems deliver the conditions trees need to grow but, in an infrastructure and services friendly way. They are engineered to be load-bearing for pavements and protect the tree roots from pressure and compaction,” continues Atkinson.

Permeable pavement was installed above the Citygreen solution to capture polluted stormwater run-off and harvest it for passive tree irrigation.

Results have exceed expectations

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The City of Newcastle reaped the benefits of their investment after only a few years:

  • 10-year growth projections were achieved in half that time
  • The new connected canopy cover now rivals the former 80-year-old trees, 10 years after planting
  • Surrounding infrastructure has been unaffected by the fast-growing root systems
  • The figs are a picture of health, restoring the amenity to the street for residents, visitors and local biodiversity
  • Three trees are hosts to an array of native birds and flying foxes

Ultimately the story of the Laman Street figs is about how these trees have been effectively managed and successfully re-introduced into the urban environment. Citygreen structural soil vaults addressed all of the problems experienced by the original Hills Weeping figs by supporting the above ground infrastructure, increasing soil volume, and reducing soil compaction to grow healthier climate resilient trees to be enjoyed by many generations to come.

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“With vast improvements in the public amenity, the Citygreen soil cell system has allowed the iconic Laman streetscape to live on, and we are pleased that it will be enjoyed by many generations to come.”

- Atkinson

“Great customer service, quick response times and a very in depth QA system with constant support.”

- Laura Wiesenekker, Project Engineer, Densford Civil -

“Citygreen is a very professional  business, and I found everything was great in terms of deliveries, product supply and information. It was all forthcoming and helped us to complete the project.”

- Keith Burns, Architect/Designer, Keith Burns Architect -

“Citygreen offered training and invaluable technical assistance during the works.”

- James Callan, Estimating Manager, Complex Co Pty Ltd -

“Our experience, in working with a Citygreen Design Studio was second to none. We found responses from the design studio to be very timely, and technically thorough. We went backwards and forwards a number of times, looking at different iterations of the design and, nothing was too much trouble to examine and explore different possibilities. I would highly recommend the Citygreen Design Studio to any future client considering using your services.”

- Sandra Smith, Principal Landscape Architect, City Of Monash -

“We are big on compliance on all projects, and the fact that their SmartCertify cloud platform covers all bases, and supports their 20 year warranties, is critical – especially that these pits are being installed under roadways and footpaths.”

- Johny Purkaystha, Civil Program Engineer, Central Coast Council -

"I reviewed all the previous projects that we have installed in the past couple years using your product and I can happily report back that we have 0% mortality in the soil cells, which is incredible!"

- Brendan Wilton, CEO, Trim Landscaping, Bedford, Canada -