Adkins Arboretum was originally slated in 1972 to be the Maryland state arboretum on the grounds of Tuckahoe State Park, a 4,000-acre park bordered by the Tuckahoe Creek in Caroline County. In 1980, the Arboretum opened with a donation from its first benefactor, Leon Andrus, a native of Queen Anne's County. The Arboretum was named after the Adkins family, an Eastern Shore family who were avid conservationists and longtime friends of Andrus. Andrus also established a private foundation, the Friends of Adkins Arboretum, to oversee the Arboretum's development. In 1989, Leon Andrus died at age 101, leaving a bequest to the Arboretum's endowment.
The Arboretum was founded with the mission of displaying all of the forest types of Maryland. By the late 1990s, with a new mission in place to display and study the indigenous plant communities of the Delmarva Peninsula, the Friends of Adkins Arboretum proposed to the state that they manage the Arboretum. A public/private partnership was made official in 1998 with the state granting a 50-year lease to the Friends of Adkins Arboretum.
Today the Arboretum is self-supporting, receiving grants from federal and state agencies and from private foundations, as well as donations from members and income from program fees, and gift shop and plant sales.