The Architect of the Capitol has embarked on a comprehensive project to restore the original arboretum of nearly 1000 trees at the United States Capitol as designed and constructed under the guidance of Frederick Law Olmsted, Sr. from 1874 to 1894. This paper presents the challenges, unexpected findings, and applications of a complex process that integrates archival research with current geospatial data for analyzing the integrity of the historic design and planning for future plantings.
Capitol Square encompasses the 56 acres of grounds surrounding the U.S. Capitol Building in Washington, D.C. This iconic landscape was planned with the clear purpose of providing a gracious, functional, and appropriate setting for the center of our nation’s democracy. Olmsted’s General Plan was carefully considered with a spatial arrangement of landscape features, including trees, creating a complementary setting with framed views, gracious approaches and a breadth of landscape that reinforced the monumentality of the Capitol.
Over the past 128 years, the as-built landscape design has experienced substantial alteration and erosion in the integrity of the tree collection. While maturation and disease as well as new construction, disruption of the grounds, security issues, and other reasons prompt removals, new plantings for commemorative and aesthetic purposes over the decades has not always considered historic precedent or intended function. This project draws on and extends cultural landscape studies to create a comprehensive treatment for the restoration of tree plantings according to the Olmsted design intent.
A cultural landscape report for Capitol Square instigated an in-depth investigation and planning effort led by Heritage Landscapes in 2012. Ten years later, the team is updating documentation and recommendations to create the definitive understanding of what Olmsted intended and eventually constructed for the tree collection and to refine the proposed treatment plan to recapture the historic character of the arboretum. Cross reference of hundreds of species and locations across the years involved deciphering Olmsted’s 1882 hand annotations and corroborating data with the Olmsted Brothers 1904 partial site inventory that alludes to what was actually planted. Use of an accurate 1956 survey increased understanding, but requires scrutiny to account for substitutions, additions, and removals over time. A tree-by-tree overlay process sought to resolve deficiencies inherent in the data.
Translating historic tree data to the current landscape of Capitol Square, the AOC is evaluating existing trees for their relation to the Olmsted design. The extant original trees and accurate replacement trees are safeguarded while other trees are slated for eventual removal. This project supports the U.S. Capitol Grounds and Arboretum’s Commemorative and Memorial Tree, and Living Collections Policies that seek to restore the Olmsted canopy accurately over time. The effort will allow Capitol Grounds and Arboretum staff to further evaluate the condition of the existing landscape and make appropriate tree species selections and placements aligned to Olmsted’s design intent and the as-constructed Capitol Grounds.
Gregory De Vries
Gregory De Vries, PLA, ASLA, (he/him) is Managing Partner at Heritage Landscapes LLC, Preservation Landscape Architects and Planners. With an extensive body of work in historic places and communities, Greg’s project background includes 19 Olmsted firm landscapes. His efforts activate cultural asset conservation, inclusive heritage-based development, and nature-culture integrated design and implementation. Greg serves as on the ICOMOS-IFLA International Scientific Committee of Cultural Landscapes and performs World Heritage field missions and resource planning activities. Holding degrees in landscape architecture, cultural anthropology, and Spanish he finds meaning elevating the stories embedded in all places.
Melissa Westbrook (she/her) is the Urban Forester at the Architect of the Capitol (AOC), U.S. Capitol Grounds and Arboretum. In her role, Melissa manages arboretum programs, including urban forestry operations, curation of living collections, and plant records. Prior to joining the U.S. Capitol Grounds and Arboretum in 2018, Melissa worked for three different National Park Service units in the National Capitol Region, most recently as the Horticulturist for the George Washington Memorial Parkway. As an ISA Certified Arborist, Melissa is interested in historic tree and landscape preservation, plant conservation, and creating more productive, healthy, and resilient urban ecosystems.