Who We Are

Our History

Memory Lane

Baltimore 1949
Educational sessions have always been a critical part of the ISA experience. Baltimore, 1949.

The International Society of Arboriculture (ISA) has served the tree care industry for nearly 100 years as a scientific and educational organization.

ISA was founded in 1924 when members of the Connecticut Tree Protective Association convened a meeting that would plant the seed of the organization that would ultimately revolutionize the tree care industry. It was this gathering that was to become the first of many annual conferences of the organization that has evolved into today’s International Society of Arboriculture (ISA). The history of modern arboriculture is largely the story of the development of ISA in the 20th century. And while such a history is not exclusively that of ISA and its predecessor organizations, there is little of significance in arboriculture that is not reflected in its publications since its inception in 1924.

ISA continues to be a dynamic medium through which arborists around the world share their experience and knowledge for the benefit of society. ISA is aligned on many fronts with other green organizations and is working hard to foster a better understanding of trees and tree care through research and the education of professionals as well as global efforts to inform tree care consumers.

To read a more complete history of ISA, download the Memory Lane brochure, which outlines our advancements within each decade.

The Legends of Arboriculture

This video provides an insightful historical record of arboriculture through the eyes of those who experienced it first-hand.

Historical Information

Since its inception at the 1924 Shade Tree Conference, ISA has grown through the hard work and dedication of our members and volunteers. Below you will find listings for every ISA President, each Annual Conference, various award winners, plus our membership growth throughout the years.

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