Local Organizations
Maine Department of Agriculture 
Maine Board of Pesticide Control 
Maine Forest Service 
Ornamental Horticulture Council
Maine Landscape & Nursery Association
Project Canopy

Regional Organizations
New Hampshire Arborist Association 
Northeast Center for Urban and Community Forestry
UMass Extension
Massachusetts Arborist Association
Massachusetts Tree Wardens & Foresters Association
New England Chapter - ISA
New Hampshire Landscape Association
Connecticut Tree Protective Association

National Organizations
Tree Care Industry Association
International Society of Arboriculture
The National Arbor Day Foundation
American Society of Consulting Arborists
Society of Municipal Arborists
The American Chestnut Foundation
Society of American Foresters
Community Trees