A Brief History of ISA and ISA Ontario

The International Society of Arboriculture (ISA) enjoys a rich heritage as a scientific and educational organization with a primary mission to disseminate information and knowledge in the care and preservation of trees.

ISA was founded in 1924 by a group of about 36 individuals – each engaged in some phase of tree work or research. This group had been called together in Stamford, Conn. by the Connecticut Tree Protection Examining Board to discuss shade tree problems and their possible solutions. A need for collaborative efforts was identified and an organization was soon born, with the name National Shade Tree Conference (NSTC). See more on ISA’s history here.

In 1942 the need for chapters was recognized, due to region-specific interests and concerns. In the fall of 1949, the first meeting of a group of Canadian Arborists met, and on Mar.4, 1950 held their first Annual Meeting in Toronto (22 attended, set dues of $10, and voted to be the 5th. chapter of the NSTC).

In 1971 the chapter incorporated as The International Shade Tree Conference-Canada Inc., then changed in 1982, (as did the parent body change it's name), to ISA-Canada Inc., and finally in 1992 to our present name, International Society of Arboriculture – Ontario Inc. See more about the formation of ISA Ontario from our Ontario Arborist archive here (Volume 17 Number 2, March-April 1989).

As part of ISA Ontario’s 75th Anniversary Conference in 2024, we asked several long-term members about their early mentors, and what ISA Ontario has meant to them and their careers. Thank you to everyone who participated and a special thank you to Rob Shaw-Lukavsky for his incredible work on this project! Watch the 75^th Anniversary video retrospective here.