By Elaine L. Mills, Extension Master Gardener
Photos by Elaine L. Mills (where not otherwise credited)
The United States Botanic Garden (USBG) in Washington, DC marked its 200th anniversary in 2020. USBG is the oldest continuously operating botanic garden in the United States. Last fall, artist Patrick Dougherty created a stickwork art installation outside the conservatory titled “O Say Can You See” to launch the bicentennial celebration. Then, in February of this year, the USBG opened a two-part major exhibition, “Deeply Rooted, Branching Outward,” giving visitors an opportunity to examine historic images of the garden and learn about plant exploration through the years, as well as to discover how the garden works today. Unfortunately, celebratory events planned for the anniversary have been cancelled after it was deemed necessary to close the garden in the spring of 2020 to limit the risk of transmitting the COVID-19 coronavirus.
In the early years of the nation, President George Washington had a vision of a botanic garden and in 1796 wrote to the District Board of Commissioners requesting that space for such a garden be included in plans for the new capital city. Other Founding Fathers, including Thomas Jefferson and James Madison, also recognized the scientific value of plants and assisted in the garden’s creation.
19th Century
The garden was established in May of 1820 when Congress approved the use of five acres of land at the foot of the U. S. Capitol. Plant specimens were already being documented, studied, and preserved as early as 1804 when Jefferson commissioned the Lewis and Clark Expedition to travel west to the Pacific Ocean. The collection of plants on behalf of the U. S. Botanic Garden was carried out by two additional expeditions. The four-year voyage (1838-1842) of the U.S. Exploring Expedition under the command of Lt. Charles Wilkes brought back 50,000 dried botanical specimens from 10,000 different plant species, as well as seeds and hundreds of living plants. Four species in the garden’s present collection – queen sago, blue cycad, vessel fern, and jujube – date back to those original plants. On the U. S. North Pacific Exploring Expedition (1852-1854), led by Commodore Matthew C. Perry, the official agriculturist Dr. James Morrow, collected dried plants, seeds, and live specimens, such as kumquat, loquat, tea, papaya, and mandarin orange, which were subsequently catalogued and studied by Harvard botanist Asa Gray.
The USBG gained a physical building to house the collected tropical plants when its first Conservatory was built in 1850. The building, located on the land first allotted by Congress, consisted of a central dome with arched windows and roof pinnacles in the Gothic style favored in the 1840s. Two main wings were later added, and in 1867, the large Palm House was constructed. This Victorian-style glass greenhouse featured an exterior observation platform and a dramatic circular staircase on the interior that concealed a brick chimney to provide heating for the plants.
In 1877 Congress purchased the “Fountain of Light and Water,” a huge illuminated fountain, that had been unveiled at the Centennial Exposition in Philadelphia the previous year. The fountain, created by Frédéric Auguste Bartholdi, the sculptor of the Statue of Liberty, was initially situated on the USBG grounds where it served as a social gathering place, but in 1932 it was moved to its present location in Bartholdi Park across Independence Avenue from the USBG Conservatory.
20th Century
In the early 20th century, when the McMillan Plan was adopted to restore Pierre L’Enfant’s original design for the city, the USBG moved across the street to its present location on Maryland Avenue. Construction of the new Conservatory took two years from the laying of its cornerstone in 1931 to its completion in 1933. The aluminum structure, measuring 83 feet high, was the largest of its kind at the time it was built.

Almost two hundred years after Washington first proposed a national botanic garden, Congress declared the rose as the national flower, and a vacant three-acre lot adjacent to the USBG was identified as the location for a future rose garden. As support for the garden grew, the design concept was greatly expanded. When the outdoor National Garden opened to the public in 2006, it included not only the original rose garden, but also a regional garden, an amphitheater, a First Ladies water garden, and a pollinator garden.

21st Century
Now, in the 21st century, the U. S. Botanic Garden has a huge production facility on 25 acres of land in Southwest Washington, DC. The greenhouses, which comprise the largest complex supporting a public garden in the United States, propagate or maintain over 65,000 plants for the garden’s collections, exhibits, and seasonal displays, as well as for Congressional offices. The USBG has a permanent living collection of over 12,000 plants, many of which are on display in the Conservatory and outdoor gardens. These include such specialized groups as orchids (the largest), medicinal and economic plants, native plants of North America, desert plants, and carnivorous plants. The collections are also available to facilitate scientific studies, such as the Smithsonian Institution’s Global Genome Initiative.
The USBG also supports new developments in the field of horticulture. Examples include the 2016 renovation of Bartholdi Park to showcase sustainable landscaping and the 2019 installation of a green roof over the Conservatory’s galleries and lobby to study the impact on stormwater runoff. Another example is the Garden’s partnership with the National Center for Appropriate Technology to provide training focused on urban farming.
A team of 69 employees, assisted by many volunteers, works to support the Garden’s mission to maintain and grow the plant collections and educate diverse audiences about the important and fascinating world of plants. While the USBG is temporarily closed, the staff continues its educational objective by sharing online virtual tours, weekly classes and demonstrations, and at-home activities for children and their families. Find these resources at USBG at Home.