American University Arboretum and Public Gardens 4400 Massachusetts Avenue NW, Washington, DC 20016
The landscaping recently met national requirements for the campus to be declared an arboretum. Note: Link is to the main campus website.
Constitution Gardens Washington, DC
50 acres park maintained by the National Park Service
Dumbarton Oaks 1703 32nd Street NW, Washington, DC 20007
10 acres of formal gardens. Gardens are closed Mondays.
Hillwood Museum & Gardens 4155 Linnean Avenue, NW, Washington, DC 20008
Marjorie Merriweather Post's Washington, D.C. estate. Reservvations required.
Kenilworth Park and Aquatic Gardens 301 7th St SW, Washington, DC 20407
"The only National Park Service site devoted to the propagation and display of aquatic plants." National Register of Historic Places.
Tudor Place 1644 31st Street NW, Washington, DC 20007
Historic house and garden. National Historic Landmark. Admission.
