In December 2015, two Hills Weeping Figs (Ficus microcarpa var. ‘Hillii’) were excavated to evaluate the root growth patterns in Citygreen’s Stratacell systems. This report documents the patterns of root growth and states key findings on the Stratacell system.

1. ROOTS IN
STRATACELL
An Evaluation
of Root Growth
PatternsJOHN ATKINS | DIRECTOR, TREEOLOGY
In December 2015, two Hills Weeping Figs
(Ficus microcarpa var. ‘Hillii’) were excavated
to evaluate the root growth patterns in Citygreen’s
Stratacell systems. This report documents the
patterns of root growth and states key findings
on the Stratacell system.
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2. Key Findings
Outline
Location of Trees
Site Conditions
Soil Profile
Tree Health
Visual inspection data
Chlorophyll Fluorescence values (CF)
Construction method (2011)
Excavation Method (2015)
Observations
Discussion
Conclusions
Appendix 1
Appendix 2
References
About the Author
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Contents
2 Roots in Stratacell | © Citygreen 2016 www.citygreen.com

3. Starting with a well grown nursery tree with an evenly distributed and well colonized rootball is
a great start to the establishment of landscape trees. The use of trees produced that conform
to NATSPEC is recommended.
The use of the Root Director barrier, Filtergrid membrane and coarse gravel established a zone
almost completely free of surface roots. The use of this system is likely to significantly minimise
the damage to paved surfaces about landscape trees.
Increasing the gaseous exchange potential at lower depths within the tree planting vault
increased root colonization and proliferation. The use of RootRain piping, a sandy loam soil mix
encouraged root development to lower depths in the tree vault system.
To increase the colonization of tree planting vaults using the Stratacell system, installing
RootRain piping throughout the vault and at varying levels is likely to achieve greater
occupancy. If the aeration system is combined with irrigation that pulses water through more of
the tree vault, especially during dry periods, occupancy levels are likely to be increased.
The Stratacell system was shown repeatedly to permit root spread in a lateral and vertical
manner within the tree vault. The Stratacell formation provided adequate space for root
development and possibly encouraged lateral spread of roots along the top surface of each
layer.
The strong correlation of root growth on the upper side of the RootRain piping indicates that
this zone provides optimal conditions for root growth. It is likely a combination of good aeration
and the water available is the major cause.
Significant root spread and depth was achieved in only 4 years of growth through the use of
the Stratacell tree planting system.
Overall tree health was not impeded by the use of the Stratacell system and generally the trees
health was found to be excellent.
The stability of trees to storm damage and wind throw resistance are likely to be improved
when trees are planted in Stratacell systems of tree vaults due to the development of deeper
roots.
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Key Findings
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4. Get the free full version of Ebook “Roots in
Stratacell” by John Atkins.
http://info.citygreen.com/roots-in-stratacell
4 Roots in Stratacell | © Citygreen 2016 www.citygreen.com