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: NDSPhoto: Root Barriers Brisbane

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