Tree Growth Tested in Silva Cells for 5 Years

Hadlow College/University of Greenwich Case Study

At DeepRoot we love to see results. Proven, tested, and validated.

A recent study was completed at the University of Greenwich, Hadlow College by Duncan Goodwin. The study planted several trees in different growing conditions and monitored their growth for 5 years. While formal results of the tests will follow, we are thrilled with the tree performance and the root mass of the trees in Silva Cells. The study was completed this week by air spade excavation to better understand how the roots move through the lightly compacted soil in the silva cells.


Tree Roots uncovered in the Silva Cell system after 5 years. Photo: Steve Chatwin-Grindey

The research into the different techniques is to highlight the environmental and social benefits of green infrastructure and how we might look at improving the urban tree establishment.


Preparing the site, 2014.

  • This is a study that consists of twelve planting areas measuring 4 x 4 metres by approximately 1.2 metres deep. Each lined with a geotextile membrane to restrict root growth beyond the extents of the pit and filled with four different types of planting systems /soils.
  • 12 trees were originally planted with their progress being continually monitored.
  • After 5 years the first 4 trees have been ground monitored are now being excavated using an air spade to expose the root system and ground-truth the GPR survey.
  • All the roots are being collected from each system recorded and weighed to log the below ground biomass, and above ground they are carrying out laser scan and destructive leaf counts and Leaf Area Index measurements.


Tree success after 5 years. 2019

DeepRoot has always been interested in improving the built environment through green infrastructure. This test, along with over 2,700 silva cell installations worldwide are further proof to the benefit of uncompacted soil in silva cells for successfully growing trees under pavement.

For more information on this project, please contact Stephen Chatwin-Grindey, Steve@deeproot.com

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