Longwood Gardens to expand and transform its renowned conservatory grounds

Longwood Gardens
Longwood Gardens
rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens.

Longwood Gardens recently unveiled plans for a sweeping yet deeply sensitive transformation of its core area of conservatory gardens, in the most ambitious revitalization in a century of America’s greatest center for horticultural display. Adding new plantings and buildings across 17 acres, Longwood Reimagined: A New Garden Experience will expand the public spaces of the renowned central grounds and connect them from east to west, offering a newly unified but continually varied journey from lush formal gardens to views over the open meadows of Pennsylvania’s Brandywine Valley.

Youtube Video Credit: Longwood Gardens

The project originates from a master plan developed in 2010 by West 8 Urban Design & Landscape Architecture with WEISS/MANFREDI Architecture/Landscape/Urbanism. Longwood has continued working with WEISS/MANFREDI as lead designer, in collaboration with Reed Hilderbrand, on Longwood Reimagined, which continues the institution’s distinguished history of commissioning and collecting outstanding garden designs and glasshouses. The project will be managed by Bancroft Construction Company, based in Wilmington, Delaware.

Longwood Gardens
Longwood Reimagined  preserve and enhance our cherished spaces … as demonstrated in this rendering of how our new restaurant and event spaces will be carved into the ridgeline facing our Main Fountain Garden.
Rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens.

In keeping with Longwood’s tradition of blending fountain gardens and horticultural display, the centerpiece and largest single element of Longwood Reimagined is the creation of a new 32,000-square-foot glasshouse, designed by WEISS/MANFREDI, with gardens and pools designed by Reed Hilderbrand. This new West Conservatory with its asymmetrical, crystalline peaks seems to float on a pool of water, while the garden inside, inspired by the wild and cultivated landscapes of the Mediterranean, is conceived as seasonally changing islands set amid pools, canals, and low fountains. In the tapestry-like garden design, iconic plants of this ecology such as aloes, laurels, blueblossom, and Greek horehound hug the ground, with higher plants such as cypress and 100-year-old olive trees rising up into the soaring space while other plantings are suspended from above. Building on the great 19th-century tradition of glasshouses through new sustainable technologies, the West Conservatory is a living, breathing building, with earth tubes and operable glass walls and roof that allow the interior garden to thrive.

Longwood Gardens
Cascade Garden
rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens.

Longwood’s Cascade Garden, the only design in North America by the great Brazilian landscape architect Roberto Burle Marx, is being relocated in its totality to an all-new, 3,800-square-foot glasshouse of its own, a jewel box where the tropical plantings will be preserved and can thrive at the heart of the conservatory ensemble. A new outdoor Bonsai Courtyard, built alongside the West Conservatory, will exhibit one of the most outstanding collections of bonsai in the country. Wood walls and hedges will create an intimate, gallery-like space with bonsai displayed on free-standing pedestals and on ledges mounted to walls. Carved into the topography that faces the Main Fountain Garden, a new public restaurant and private event space with a series of vaults reveals the spectacular fountain displays. Above the restaurant and event space, the landscaping of a new South Terrace and South Walk provides a shady promenade extending along the existing and new conservatories to a new West Terrace, where the landform echoes the arc of a stand of hundred-year-old plane trees and frames views out toward the Brandywine’s meadows.

Bonsai Courtyard
rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens.

Other elements of the $250 million Longwood Reimagined project include the construction of a new education and administration building with a state-of-the-art library and classrooms; renewal of the beloved Waterlily Court designed by Sir Peter Shepheard (1913-2002); and preservation of six historic Lord & Burnham glasshouses from the early 20th century, to be relocated at a later date and used for year-round garden displays. As part of the initial phase of transforming the area, Longwood’s beloved century-old Orchid and Banana Houses will close on March 1 for preservation and will re-open in time for Longwood’s 2021 year-end holiday display.

Waterlily Court
rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens.
West Conservatory
rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens.

Douglas Reed, partner and principal of Reed Hilderbrand, said: “We felt our first responsibility in reimagining this expansive area of the grounds was to give expression and identity to the idea in the master plan to extend the conservatory complex along the high ridge. We drew inspiration from existing features of Longwood’s landscape, among them tree-lined walks. The expansion scheme structures trees to define space and direct movement, recognizing Longwood’s origins as an arboretum. Above all, we felt this ambitious project must retain the character and warmth associated with Longwood’s origin as an arboretum and country estate.”

A multitude of subtle and imaginative architectural elements link the components across all 17 acres of the project site. The graceful curvature of the steel tree-branch columns of the West Conservatory enables them to be slender while bearing their load. At its highest point, the roof of the West Conservatory matches that of the Main Conservatory, reinforcing the connections across the site. At the same time, the West Conservatory’s roofline surprisingly dips and rises again in a catenary, carrying WEISS/MANFREDI’s sense of gentle, organic processes into the architectural forms. Within the new restaurant and event space, trellis-like ceiling vaults and arches echo the forms of the Main Fountain Garden and further reveal connections between the architecture and garden. This theme is extended to reimagining the Waterlily Court, which is framed by a new arcade that redefines the court as an outdoor room and central destination.

Reed Hilderbrand’s design for the expanded landscape offers visitors an itinerary of grand walks and new and restored gardens, with places for gathering and pause provided throughout the intensive experience. Each garden reflects its identity and purpose: a West Walk that serves for strolling and orientation, a Central Grove along the Waterlily Court that serves as an entry to the new West Conservatory and relocated Cascade Garden, a walled Bonsai Courtyard that provides space for the exhibition of rare bonsai, and the expanded green of the West Terrace celebrating the grove of hundred-year-old plane trees.

Rendering courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens

A key element of Longwood Reimagined is the relocation and reconstruction of the Cascade Garden. Planned in consultation with WEISS/MANFREDI, Reed Hilderbrand, Burle Marx Landscape Design Studio, and a panel of preservation experts convened by Longwood, this is the first time that a historic garden has been relocated as a whole. Burle Marx designed the Cascade Garden in 1992 within an existing structure, which was retrofitted to accommodate hundreds of tropical plants, 35 tons of rock, and 3,000 feet of heating cable. Now this ensemble of richly textured plants that evokes elements of the rainforest—palms, bromeliads, philodendrons, and more—set amid vertical rock walls, cascading water, and clear pools will be moved into a new, custom-designed glasshouse.

Longwood expects to break ground on the project in Spring 2021. The Main and East Conservatories will remain open throughout the transformation, and Longwood Gardens will continue to present an ongoing schedule of events and performances.

Text: Longwood Gardens

Renders: courtesy of WEISS/MANFREDI with Reed Hilderbrand for Longwood Gardens

About Damian Holmes 3293 Articles
Damian Holmes is the Founder and Editor of World Landscape Architecture (WLA). He is a registered landscape architect (AILA) working in international design practice in Australia. Damian founded WLA in 2007 to provide a website for landscape architects written by landscape architects. Connect on Linkedin at https://www.linkedin.com/in/damianholmes/