Slayton Arboretum officially began in 1922 when Mr. and Mrs. George A. Slayton donated 14 acres to Hillsdale College to celebrate the 50th anniversary of their graduation. But the site’s use by the College students dates back to at least the 1860s, when the land was known as Van Valkenburgh’s cow pasture. The pasture had a large, wooden knob, nicknamed Mt. Zion, which was used as a retreat for orations, marshmallow roasts and scenic inspiration.
Dr. Bertram A. Barber, a professor in the Biology Department at Hillsdale College, envisioned creating a functional Arboretum on the site as an outdoor laboratory and field station for students and as a biological garden for the community. Additional land soon followed, and by 1924, Dr. Barber’s dream of an Arboretum was fulfilled through donated plants and the labor of Hillsdale students and volunteers.
Dr. Barber excavated a pond in 1928 and further refined it in the following year. The stone field station, a hillside rock garden, waterfall and a pump house were added to the site in 1929. Dr. Barber, his students, his brother Austin and his father Robert provided the stonework. A fieldstone gazebo still offers a commanding view of the Arboretum and campus.
The two concrete bridges spanning the pond and lagoon were donated in the early 1930s and designed and built by artisans Corone and Cardoza to look like wood.
The amphitheater was added in the late 1930s when the city of Hillsdale donated a 2½ acre former gravel pit to the College. The steep quarry walls made for excellent acoustics, and Dr. Barber and his crew constructed a stage, landscaped with evergreens. The B.A. Barber Amphitheater was dedicated on Memorial Day, 1939. That same year, Slayton Arboretum was listed as one of Michigan's Points of Interest, and up to 700 people a day visited the site.
Dr. Barber retired in 1955, but stayed active in the Arboretum’s operation until his death in 1967. The Maintenance and Grounds Department at Hillsdale College assumed the basic operation of the Slayton Arboretum at that time and has continued to provide mowing, trimming and maintenance for the site.
The 1970s, 1980s and 1990s saw extensive repairs and restoration to the Arboretum’s buildings and grounds, as well as the addition of several new gardens, new trails, labeling and mapping of trees and the installation of a red iron bridge to allow access across the Barber Drive wetland. An annual plant sale, launched with the help of the Hillsdale Evening Garden Club, generates funds used to make improvements in the Arboretum.
Completed improvements in the last several years include the Barber House, which serves as a visitor center, library and meeting room; repairs to the stonework, waterfall and rock garden, a cast-iron fence around the perimeter of the to keep out deer, and the implementation of many community outreach activities, such as summer classes, the Arbor Day Celebration and the Fall Festival and the new Children’s Garden.
In 1991, the Board of Women Commissioners created an endowed chair in the Biology Department at Hillsdale to allow a botany professor to oversee the development, care and maintenance of Slayton Arboretum. Dr. Ranessa Cooper currently holds the chair and serves as Director of Slayton Arboretum.