He began his education at Mount Hermon School in Massachusetts, after which point he entered Hofstra College to pursue a career in music.

The tenure of his administration is remembered as the most difficult financial period for NYBG, and Irwin is credited with leading the organization during a very challenging time.

[5] Donald J. Bruckmann, chairman of the board of managers of the New York Botanical Garden, wrote of Irwin upon his departure: "Under his stewardship he brought the Garden to new eminence in the world of horticulture and plant science, and made it a great cultural institution in the city with the highest standards in the world.

"[9] In addition to his administrative work, Irwin is credited with initiating the Planalto do Brasil Program for the botanical study of the Brazilian Highlands region.

Wolff graduated from Oberlin College in 1946[12] and earned a master's degree from the Columbia University School of Social Work.