Soil Vault Systems

Soil Vaults

What is a Structural Soil Vault?

structural soil vault system otherwise known as soil cells are an underground matrix that is designed to provide space for soil and vegetation in urban areas where there is limited space for traditional landscaping and trees.

Soil vaults in urban environments are typically made up of modular units that can be stacked on top of each other to create a multi-level structure. These structures are designed to provide adequate growing medium for plants and trees, while also providing stormwater management and infrastructure safety against tree roots, and other environmental benefits.

Why do Urban Trees need a Structural Soil Vault System?


Not every soil structure is conducive to the growth of plants and trees, urban soil least of all. Tree growth and fertility are strongly influenced by the compaction and composition of soil, as it affects the movement of air, water, and other nutrients required for trees to flourish. Effectively the ‘architecture of the soil’, it is the most critical element in the success or failure of urban trees.

Well-structured soil functions like a reservoir. It enables trees and their roots the ability to accept, store and transmit water, nutrients, and energy and provides room in which roots can propagate. Good quality soil allows the space required for life and the necessary biochemical exchanges for growth.

Urban trees are frequently planted in cramped pits with inadequate subsoil otherwise known as Structural soil, leading to stunted growth and root systems that explore the area beneath paved surfaces in search of nutrients. This can cause significant damage to the integrity of urban infrastructure, resulting in upheaval and safety hazards. Citygreen’s innovative soil vault products provide landscape architects, engineers, and arborists with the tools to create robust and structurally beneficial systems that accelerate healthy root growth and prevent infrastructure damage, fast-tracking the success of both urban tree planting initiatives and surrounding construction.”

Why Trees need Uncompacted Soil

Uncompacted soil is vital for trees as it allows their roots to penetrate and expand more freely, establishing a robust root network crucial for stability and nutrient absorption. Loose soil promotes better oxygen and water movement, essential for root respiration, hydration, and nutrient uptake, fostering faster tree growth and development.

Why Cities need Compacted Soil

Cities and urban centres need compacted soil to support pedestrian movement, vehicular traffic loads, paved surfaces need a solid and compacted ground. However, this makes it challenging to provide adequate space for urban trees without compromising the structural integrity of the pavement or compromising and giving the tree less then ideal living conditions which leads to diminished returns from the tree and early tree death.

10 Year  Tree Growth Comparison

Citygreen provides local governments, landscape architects, engineers, and arborists with high-quality soil-volume products that create strong and structurally beneficial systems. These systems promote root growth while also providing sufficient support for urban infrastructure, allowing for the successful integration of urban trees into the built environment.

Contact us for more information on its importance and the soil structure systems that we can provide.

Learn More about Soil Vaults for Healthy Trees Here

“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 -