The greenhouse complex, covering 85,000 square feet under glass, is the largest support facility for a US botanic garden in the United States, in a very out-of-the way location in Washington DC. Shown above is the alleé of Phoenix sylvestris from India & Nepal.
It houses collections that are not on display at the US Botanic Garden complex at the foot of Capitol Hill. Seasonal plants are grown here for the Capitol grounds, the Supreme Court, and the Library of Congress -- about 100,000 mums, pansies, cabbage, kale and other annuals and perennials.
Foliage plants are grown here for supply to Senate offices; palm trees are available to rent for special Capitol Hill events; and interior display plants like poinsettias and Easter lilies are grown for special seasonal displays.
But these greenhouses also serve far more important functions. They act as an R&R facility for plants from the botanic garden that simply need a rest and recovery. After all, more than 750 thousand visitors a year traipse through the site, which takes a toll on plants.
Greenhouse botanists also care for about two thousand rare and/or endangered plants (like the orchid shown here) seized by US customs agents under CITES, the Convention on International Trade in Endangered Species. (Yes, that's what happens to rare plants that are confiscated at airports and borders!). The USBG is one of 62 botanic gardens around the country designated as repositories for these special plants.
And almost more plants than you could possibly imagine. According to botanist Kyle Wallick, there are about 50 thousand plants on hand at the production facility at any one time. Check the US Botanic Garden website early next year for this annual event that you shouldn't miss.