Essential Architecture- Washington D.C.

United States Botanic Garden


Greenhouse- Lord & Burnham


National Mall, Washington, D.C. (on the U.S. Capitol Grounds campus near Garfield Circle)


The United States Botanic Garden (USBG) is a botanic garden run by the Congress of the United States. It is located in Washington, D.C., on the U.S. Capitol Grounds campus near Garfield Circle. The building itself, which includes a large Lord & Burnham greenhouse, is divided into separate rooms, each one simulating a different habitat.

The USBG is supervised by the Architect of the Capitol, who is responsible for maintaining the grounds of the United States Capitol. Although a ward of Congress, the USBG is open every day of the year, including federal holidays. This also means that the institution belongs to the American Public. It cannot be commissioned for private, for-profit events.


The Conservatory

In 1838, Charles Wilkes set out on an explorative mission commissioned by Congress to circumnavigate the globe. During this trip, Wilkes collected live and dried specimens of plants, being one of the first such expeditions to make use of wardian cases to maintain live plants on a long voyage. The expedition returned in 1842 with a massive collection of plants previously unknown in the United States. The dried specimens comprised the core of what is now the National Herbarium, which is curated by the Smithsonian's National Museum of Natural History. The live specimens and seeds came to be housed in the Old Patent Office greenhouse, and were cared for there until 1850. At that time, a botanic garden was built to house the collection, and existed in front of the Capitol; this location is now home to a reflecting pool. In 1933, the building was moved to its present location, just to the southwest of the Capitol. It is bordered by Maryland Avenue on the north, First Street on the east, Independence Avenue on the south, and Third Street on the west. The building was closed for renovation on September 1, 1997, and reopened to the public on December 11, 2001. At the time of closure for renovation, plants in the collection were placed in storage at the U.S. Botanic Garden Production Facility, retired to greenhouses in Florida, or composted.

The Botanic Garden also cares for Bartholdi Park, on its south side, which is so named for the beautiful fountain in the garden's center, designed by Frédéric Bartholdi.

Construction was completed on the three-acre National Garden on the USBG's west border, an annex of the US Botanic Garden, in October 2006. The National Garden is funded by the National Fund for the U.S. Botanic Garden and includes a regional garden of plants native to the Atlantic Coastal Plain, a Rose Garden, a butterfly garden, and the First Ladies Water Garden.

Physical Plant
The USBG proper consists of three locations: the Conservatory, Bartholdi Park, and the Production Facility.

The Conservatory
The Garden Conservatory consists of 10 "rooms" and two courtyards: the Garden Court, Rare and Endangered Plants, Plant Exploration, the Orchid House, Medicinal Plants, the Desert, the Oasis, the Garden Primeval, Plant Adaptation and the Jungle, and the Children's Garden and Meditation Garden (Southern Exposure) Courtyards. Each of these rooms highlights the uniqueness of plants in some way, or teaches about the goals of the USBG. The largest room is the Jungle, which also has a 2nd story catwalk, so that the jungle canopy may be observed from both below and above.

None of the garden is air-conditioned, save the Oasis and the Administrative offices. Each room is closely monitored by computer-operated sensors to maintain the environment best stuited to the plants in that room. Humidity, sunlight and temperature are regulated by means of a misting system, retractable shades and levered windows. All plants are watered daily by hand.

Bartholdi Park
Bartholdi Park lies just south of the Conservatory, across Independence Avenue. One of the goals of this garden is to provide inspiration and ideas for home gardeners who visit it. It displays a variety of small structured and non-structured gardens, and infuses color, shape, and planting themes. One section of the garden is certified as a National Wildlife Federation Backyard Wildlife Habitat. The Park also houses the main administrative building for the USBG.

Production Facility
The USBG also maintains a production facility in SW DC, used for growing and storing plants for propagation, for the maintenance of the collection, or for display in upcoming annual shows.


The USBG participates in CITES, the Convention on International Trade in Endangered Species, which means that it cares for plants claimed by US Customs. It specializes in orchids and succulents.

Aside from the outdoor courtyards, the plants contained within the Conservatory are tropicals. The Meditation Garden courtyard is unofficially known as the Southern Exposure. This has two meanings for the gardeners who tend this garden. First, the courtyard is on the south side of the building, so it receives more warmth, and is surrounded by glass walls; this helps to create a microclimate simulating a more southerly latitude. Second, the courtyard is planted with plants from the Southeast and Southwest United States, (which, if not for the microclimate, would not be able to live in harsher District of Columbia weather), thus "exposing" visitors to the "south".

The Children's Garden courtyard has a variety of temperate-thriving annuals used to encourage interest in plants in a fun and entertaining way.

Wilkes Plants
There are four plants in the garden that are believed to be directly related to the original Wilkes Expedition.

The Vessel Fern, Angiopteris evecta, situated in the Jungle, is believed to be the direct progeny of the Vessel Fern brought back on Wilkes' ship. Because of the life span of Vessel Ferns, it is highly unlikely that the present fern is the original; however it is believed that the present fern is a direct descendant and genetically identical to the original.

The Ferocious Blue Cycad, Encephalartos horridus, is questionably one of the original Wilkes plants. Due to its size and possible age, some believe this plant to have come back with the expedition in 1842; unfortunately, early records are incomplete and inaccurate, so this is left to speculation.

The Sago Palms, Cycas circinalis, also cycads, live in the Garden Court. The USBG cares for both a male and a female of the species, and both were brought back with the Wilkes Expedition.


U.S. Botanic Garden Official website