The Capitol Grounds and Arboretum jurisdiction is responsible for maintaining and preserving the significant historic landscape and accredited arboretum designed by Frederick Law Olmsted. The grounds encompass 295 acres of landscape and infrastructure across Capitol Hill, including Union Square — the 13-acre site situated between the U.S. Capitol's West Front and the National Mall. In addition, the jurisdiction routinely performs periodic landscape maintenance, mowing, comprehensive tree care, and upkeep of the supporting infrastructure, vehicles and equipment.
With more than 18.5 miles of sidewalks, 8.5 miles of driveways and irrigation systems, maintenance of these facilities requires constant upkeep. The jurisdiction also preserves and maintains the historic stone walls, ornamental fountains and other decorative features of the U.S. Capitol grounds. Campuswide horticultural initiatives, seasonal display plantings, care for over 4,600 trees, memorial tree planting, Capitol Christmas Tree support, snow and ice removal, trash collection and support of major events also fall under this jurisdiction's responsibilities.