PlantAmerica — Biography for Michael A. Dirr

Michael A. Dirr’s lifelong passion for horticulture has positively influenced a generation of students, gardeners and plantspeople. His teaching, research and writing endeavors have advanced the art and science of horticulture and gardening. And now he has advanced the state-of-the-art with the Woody Plant Photo-Library on CD-ROM.

Dirr’s love of gardening was inherited from his father. In the summer months Mike and his sisters operated a roadside fruit and vegetable stand. Early hunting expeditions evolved into plant identification classes.

After graduation in 1962 from St. Xavier High School, Cincinnati, Ohio, with ample grounding in the classics, Dirr matriculated at the Ohio State University. Dirr received a B.S. and M.S. from Ohio State and a Ph.D. in Plant Physiology from the University of Massachusetts, Amherst, in 1972. Throughout his high school and undergraduate education, Dirr worked in nurseries and garden centers. During the Ph.D. program, he and his wife Bonnie purchased a small home with an acre of land and established their first garden. This gardening passion continues to the present with the evolution of their Georgia garden which Mike defines as sanctuary for the eclectic, eccentric, and exciting plants.

In 1972, after graduation from the University of Massachusetts, Dirr became Assistant Professor of Ornamental Horticulture at the University of Illinois, Urbana, and in 1977, was promoted to Associate Professor. From July, 1978, to June, 1979, he was a Mercer Fellow at the Arnold Arboretum of Harvard University.

In 1979, he became Director of the University of Georgia Botanical Garden. During this time he was instrumental in raising three million dollars for the new Visitor’s Center/Conservatory Complex and also charted a course for plant collections development. He returned to teaching and research at the University of Georgia in 198 1, and was promoted to Professor in 1984.

In 1991, he spent a six-month sabbatical as a Putnam Fellow at the Arnold Arboretum. Dirr and his graduate students have maintained research programs that encompass plant nutrition, metabolism, cold hardiness, propagation, evaluation and introduction. Dirr has served as major advisor to 23 M.S. and Ph.D. students as well as acting as a committee member to countless other graduate students.

Dirr has published over 300 scientific and popular publications and has authored or coauthored five books. His Manual of Woody Landscape Plants — Their Identification, Ornamental Characteristics, Culture, Propagation and Uses, Fourth Edition, is the most widely adopted teaching and reference text in the country and has sold over 150,000 copies. With Dr. Charles Heuser, he produced The Reference Manual of Woody Plant Propagation, which has become the standard reference for plant propagators. Dirr started a publishing company, Varsity Press, Inc., which has produced three books. A new Photographic Treatise is written and edited and will be published by Timber Press in 1995/1996. Currently, one other CD-ROM is being produced which will be interactive with the MANUAL with over 1500 photographs and extensive search capabilities.

Dirr has presented hundreds of lectures and seminars to colleges, industry groups and garden organizations. He travels extensively and has used the opportunity to study and photograph plants. With Dr. Allan Armitage, Dirr has led 15 garden study tours abroad.

Dirr has received numerous awards and honors during his career including the Silver Medal for Excellence in Horticultural Writing and the Jackson Dawson Medal for Outstanding Contributions to Plant Propagation from the Massachusetts Horticultural Society. He has received the Silver Seal from the National Federation of State Garden Clubs and in 1993 the Medal Honor from the Garden Clubs of America and the Scott Medal from Swarthmore College.

Dirr has positiviely improved the horticulture profession particularly at the undergraduate and graduate levels. His students permeate academia and industry. His lectures and writings have fostered an appreciation for new plants. His Georgia Plant Introduction Program has introduced over 30 new cultivars in the nursery trades. He has been generous with his time, sharing a love of plants with students, professional and amateur gardeners.