Best Management Practices for Community Trees A Technical Guide to Tree Conservation in Athens-Clarke County, Georgia The Unified Government of Athens-Clarke County, Georgia, believes that we all have a responsibility to manage our community trees wisely and to conserve valuable community resources. To contribute to this mission, Athens-Clarke County has developed this Technical Guide to Tree Conservation in Athens- Clarke County… Best Management Practices for Community Trees A Technical Guide to Tree Conservation in Athens-Clarke County, Georgia Written by-- Constance P. Head Urban Forester and ISA Certified Arborist Technical Forestry Services Robinson Fisher Landscape Architect Robinson Fisher Associates Maureen O’Brien Landscape Architect Robinson Fisher Associates With special contributions by— Roger Cauthen Landscape Management Division Administrator and ISA Certified Arborist Athens-Clarke County Central Services Department Athens-Clarke County Planning Department Urban Tree Advisory Committee and the Future of Trees Committee Adopted April 3, 2001 To obtain additional copies of this document or to find out more about the Athens-Clarke County Community Tree Program, visit the Landscape Management Division Office at 350 Pound Street, Athens, GA 30601. Best Management Practices for Community Trees Table of Contents Introduction..................................................................................................................................................1 Who Should Use This Guide .........................................................................................................1 How To Use This Guide .................................................................................................................2 The Athens-Clarke County Community Tree Program...............................................................3 Section 1: Tree Basics ................................................................................................................................5 Our Community Trees....................................................................................................................5 The Benefits of Trees.....................................................................................................................5 The Cost of Trees ...........................................................................................................................7 Tree Structure .................................................................................................................................8 Tree Growth ..................................................................................................................................10 The Critical Root Zone and Tree Protection Zone ....................................................................11 Section 2: Best Management Practices for Tree Selection and Placement ........................................15 Large Landscape Areas...............................................................................................................17 Road Frontage Areas ...................................................................................................................21 Parking Lots..................................................................................................................................27 Plazas and Downtown Settings ..................................................................................................35 Buffers ...........................................................................................................................................39 Riparian Zones and Drainage Areas...........................................................................................43 Utility Corridors ............................................................................................................................47 Section 3: Best Management Practices for Tree Care..........................................................................53 Tree Conservation ........................................................................................................................55 Tree Protection .............................................................................................................................61 Soil Health Maintenance ..............................................................................................................69 Tree Establishment ......................................................................................................................73 Tree Maintenance .........................................................................................................................79 Tree Pruning ....................................................................................................................79 Tree Mulching ..................................................................................................................83 Tree Fertilization..............................................................................................................87 Tree Irrigation ..................................................................................................................91 Pest Management............................................................................................................95 Tree Removal and Replacement .................................................................................................99 Section 4: Best Management Practices for Tree Species Selection .................................................103 Tree Species Selection ..............................................................................................................103 The Athens-Clarke County Tree Species List .........................................................................107 Appendix ..................................................................................................................................................115 Best Management Practices for Community Trees Athens-Clarke County, Georgia Introduction Best Management Practices for Community Trees is a Technical Guide to selecting, placing, conserving, protecting, maintaining, establishing, removing, and replacing trees in Athens-Clarke County (ACC), Georgia. Community trees include all trees within ACC, regardless of where they are located. They may be found growing on public or on private property. They are located in residential yards, along street right-of-ways, around commercial and industrial buildings, in parking lots, in parks, and on the grounds of government and institutional facilities. A healthy, functional, and attractive tree growing in any one of these locations provides benefits not only to the property owner, but to the surrounding community as well. The Best Management Practices (referred to throughout the Guide as “BMPs”) are technically correct and widely accepted practices and standards used by professional arborists, urban and community foresters, landscape architects and other tree care and landscape professionals. The goal of the BMPs is to provide you with basic and practical information on how to best accomplish the most important tree management activities. The goal of tree management is to maintain tree, forest, environmental, and community health. Who Should Use This Guide If you are a— • Athens-Clarke County Resident • Athens-Clarke County Unified Government Official or Staff Member • Construction Contractor or Employee • Engineer • Heavy Equipment Operator • Land Developer • Landscape Architect • Landscape Maintenance Contractor or Employee • Neighborhood Association • Planner • Tree Care Service Contractor or Employee --then this Guide is for you! Your implementation of the BMPs is an important component of our overall community tree management program. This Guide is also intended to support the ACC Development Code, and should be used as a project planning and implementation tool, a community education tool, and standards for community tree care. - 1 - Best Management Practices for Community Trees Athens-Clarke County, Georgia How To Use This Guide This Guide is organized into four (4) sections that follow this Introduction. They are— Section 1 Tree Basics Section 2 Best Management Practices for Tree Selection and Placement Section 3 Best Management Practices for Tree Care Section 4 Best Management Practices for Tree Species Selection The Guide also includes an Appendix containing a list of References and a sample Tree Management Cost Worksheet, a tool for tree conservation and management planning. Within each section a number of topics—basic subjects, site situations, and tree care activities—are addressed. BMPs are listed for each site situation and tree care activity. The BMPs are preceded by a list of the benefits and common mistakes made in tree management. It is suggested that you read through the entire Guide to gain the greatest understanding of the BMPs. However, the Guide is arranged so that you can easily find information on a specific topic by using the Table of Contents. The following summary of the contents may also help you to find the information you need. Tree Basics are included in Section 1 and are provided to increase your understanding of: Our Community Trees, The Benefits of Trees, The Cost of Trees, Tree Structure, Tree Growth, and The Critical Root Zone and Tree Protection Zone. This basic information is essential for anyone who impacts trees in