Dr. Michael Dirr is a world-renowned woody plant expert, horticulturist, and author, widely regarded as one of the most influential figures in the field of trees and shrubs. As a professor at the University of Georgia for over 30 years, he has shaped modern horticulture through his research, teaching, and groundbreaking plant breeding efforts.
Dr. Dirr played a pivotal role in the establishment of the Center for Applied Nursery Research (CANR), where he worked closely with industry professionals to advance the development of superior ornamental plant varieties. His research has led to the introduction of many improved tree and shrub cultivars, particularly within the hydrangea genus. His breeding efforts have revolutionized the industry, yielding game-changing cultivars such as Endless Summer® Hydrangea, the first widely available reblooming hydrangea, which transformed the commercial landscape of the plant market.
He is also a prolific author, with Dirr’s Hardy Trees and Shrubs and the industry-standard Manual of Woody Landscape Plants serving as essential references for horticulturists, landscape architects, and nursery professionals.
A passionate educator and speaker, Dr. Dirr is revered for his deep knowledge, keen observational skills, and direct, insightful approach to plant science. His contributions to horticulture have been recognized with numerous awards, solidifying his legacy as one of the most respected voices in the industry.