About the Arboretum


Fast Facts About the Arboretum


Established in 1927 by an Act of Congress, the Arboretum is administered by the U.S. Department of Agriculture’s Agricultural Research Service.


To serve the public need for scientific research, education, and gardens that conserve and showcase plants to enhance the environment.


Northeast Washington, DC, with entrances on New York Avenue and R Street. There are research locations in Washington, DC; Glenn Dale, Maryland; Beltsville, Maryland; and McMinnville, Tennessee.


446 acres with 9.5 miles of winding roadways.

The U.S. National Arboretum is a public garden, research facility, and urban green space located in Northeast Washington, DC. Comprised of 446 acres, the Arboretum is a place of research, education, and discovery as well as an oasis of open space in the Nation’s capital.

The Arboretum maintains many valuable and one-of-a-kind collections, from notable native plants to exotic rarities in collections like Asia Valley. The gardens and collections are valuable for both aesthetic and scientific purposes. The iconic Azalea Collection, is a Washington favorite with 10,000 azalea planted throughout Mt. Hamilton’s hillsides. The Azalea Collection is such a sight to behold in early spring when the plants are in bloom that it was the azalea bloom that first prompted the Arboretum to open its doors to the public in 1949. The Boxwood Collection may not be as showy but its scientific value is clear. It is the most complete collection of boxwood germplasm in the world with 150 different species and cultivars.

Besides maintaining its many gardens and collections for science and pleasure, the Arboretum has an active plant research component. Throughout its 80 year history the Arboretum has used careful breeding and selection to create new cultivars with improved characteristics such as look, bloom color, timing, and length, hardiness, and drough resistance. Through its ongoing plant research the Arboretum has released over 650 new plant introductions. These plants now grace homes and gardens across the nation. Particularly notable is the Arboretum’s work on flowering cherry trees, crape myrtles, and lilac. To learn more about the research work at the Arboretum, please visit the USNA website.