The Board of Trustees of the Massachusetts Horticultural Society (MHS) has announced its 2020-21 Honorary Medals recipients.
They were celebrated for “their contributions to excellence in horticulture for the public good” at the Honorary Medals Dinner at The Gardens at Elm Bank on November 4.
Robert A. Bartlett Jr., Chairman and CEO of Bartlett Tree Experts, will be receiving the George Robert White Medal of Honor. The George Robert White Medal of Honor was established in 1909 and is among the most distinguished horticultural awards in the United States. The first honoree was Charles Sprague Sargent, Director of the Arnold Arboretum. Other recipients include Gertrude Jekyll, Jens Jensen, The Royal Horticultural Society, Massachusetts General Hospital, and Tasha Tudor. Joining these distinguished honorees, Bartlett represents the third generation of the F.A. Bartlett Tree Expert Company, the world’s leading scientific tree and shrub care company. Since its founding in 1907, the company has protected the health, beauty, and value of trees—one of Earth’s most important natural resources.
Steve Castorani and Mark Sellew, co-owners of American Beauties Native Plants, will be jointly awarded the Thomas Roland Medal for their leadership in developing, selecting, propagating, and marketing numerous superior cultivars and establishing nationally recognized brands. The Thomas Roland Medal is awarded for exceptional skill in horticulture and lectures.
Thomas G. Ranney, JC Raulston Distinguished Professor at North Carolina State University, in recognition of his research programs, will receive the Jackson Dawson Memorial Medal which recognizes exceptional skill in the science or practice of hybridization or propagation of ornamental plants.
Gold Medals for eminent horticultural accomplishments or for outstanding service to MHS will be awarded to William (Ned) Friedman, Director of Arnold Arboretum; Katherine K. Macdonald, former President and Executive Director, MHS; and John Cronin, Penni Jenkins, and Heidi Kost-Gross, Volunteers, MHS.
Michael Dosmann, Arnold Arboretum, Keeper of the Living Collections, will receive a Silver Medal for his noteworthy service in horticulture. MHS Volunteers Sarah Cummer, Kathi Gariepy, and Rosalind Hunnewell will also receive silver medals.

Widely regarded as one of the world’s foremost horticulturists, Armitage is a professor at the University of Georgia, Athens, where he teaches, conducts research on new garden plants, and runs the University of Georgia Horticulture Gardens. He is generally credited with creating the concept of the independent trial garden, the first one of which opened in Athens in 1982. He is the author of ten books, including Armitage’s Native Plants for North American Gardens and Armitage’s Garden Annuals. He has been cited as one of the ten most influential people or organizations in the floriculture industry.
Also to be honored is Holly Shimizu, Executive Director of the U.S. Botanic Garden in Washington, D.C. Ms. Shimizu, who will receive the Thomas Roland Medal, has been responsible for the overall operation of the USBG for the past nine years and, under her leadership, the widely acclaimed new National Garden opened 2006. Ms. Shimizu is well known through her work as one of the hosts of The Victory Garden and as a frequent commentator on horticultural topics for National Public Radio.