National Arboretum

Washington, District of Columbia, United States

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July 19, 2026

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The United States National Arboretum is a botanical research institution in Washington, D.C., established by Congress in 1927. It spans 446 acres and is operated by the U.S. Department of Agriculture's Agricultural Research Service.1

The arboretum cultivates over 7,000 types of plants, with notable collections of azaleas, bonsai, camellias, hollies, apple trees, and conifers. It also features the National Grove of State Trees and the original columns from the U.S. Capitol's East Portico. The grounds are open to the public and attract over 500,000 visitors annually. The arboretum is a significant center for horticultural research, with a botanical library and an herbarium containing over 650,000 preserved specimens.1

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Washington, D.C.
Parks and open spaces
The National Arboretum, which encompasses 446 acres (180 hectares) of rolling hills in Northeast D.C., was established by Congress in 1927 for environmental research. It has one of the largest collections of azaleas in the country, as well as a collection of bonsai plants ranging in…
Read More
The National Arboretum, which encompasses 446 acres (180 hectares) of rolling hills in Northeast D.C., was established by Congress in 1927 for environmental research. It has one of the largest collections of azaleas in the country, as well as a collection of bonsai plants ranging in…
Read More