1. Strengthening our Community Tree Canopy Through Education
Module #9: Root Barrier Selection & Installation
Laura Sanagorski, Environmental Horticulture Extension Faculty

2. Strengthening Our Community Tree Canopy
2012 Urban Forestry Series
This series is a part of a project titled “Strengthening Our Community Tree Canopy Through Education”.
This project is made possible by  a grant through the 2011 National Urban and Community Forestry Grant Program and the Florida Department of Agriculture and Consumer Services, and the Florida Forest Service.

3. Root Barrier Selection / Installation

4. Root Barriers – the Need
Installed vertically
Prevent root penetration, redirect growth
Protection of new and existing utilities
Photo: UF Laura Sanagorski

5. Root Barriers – the Need
Tree relocation
Deflecting roots near sidewalks
Large trees planted near foundations
Photo: UF Laura Sanagorski

6. Root Barriers - Types Chemical Physical Two dimensional
Three dimensional
Inhibitors – fabric embedded with herbicide (often trifluralin)
Traps – (woven nylon / copper screen) allow penetration but not enlargement
Deflectors – physical barrier: redirect growth
Coarse gravel

7. Root Barriers: Configuration
Linear – Along Narrow Trench
Circular – Around ball of Newly Planted Tree
Photo: Root Barriers Brisbane
Photo: NDS

8. Root Barriers - Design Vertical ribs – deflect roots downward
Locking wings or tabs
Newer barriers have more rugged tops
Photo: NDS

9. Root Barriers - Homemade
Coarse gravel
Tubing
Screen
Fabric
Image: Justin Morganroth

10. Root Barriers – Testing Treatments
Biobarrier – most effective at deflecting roots deeper
DeepRoot – not effective in reducing root growth in top 4” of well-drained or poorly-drained soil
Polyethylene Plastic - not effective in reducing root growth in top 4” of well-drained or poorly-drained soil
Clean gravel- only one effective
No effect on root diameter
Photo: Biobarrier
Adapted from Gilman, 2006.

11. Root Barriers - Installation
Recommended to be done by a qualified tree professional
Gilman (2006) recommends installation at deeper than 12”

12. Strengthening our Community Tree Canopy Through Education
Module #9: Root Barrier Selection & Installation
Laura Sanagorski, Environmental Horticulture Extension Faculty