New Buildings and Landscapes by Renowned Firms of WEISS/MANFREDI and Reed Hilderbrand

Making Good Progress Across 17 Acres of Longwood’s Core Gardens Project to Open in Fall 2024

Kennett Square, PALongwood Gardens, America’s greatest center for horticultural display, today shared project updates about Longwood Reimagined: A New Garden Experience, which will open in Fall 2024. The centerpiece and largest single element of Longwood Reimagined—a 32,000-square-foot glasshouse designed by WEISS/MANFREDI, with gardens, pools, and fountains designed by Reed Hilderbrand—is now fully under glass with 1,958 glass panels installed. Concrete is being poured for its interior walkways and the installation of signature water features has begun. The bespoke 3,800-square-foot glass conservatory—designed by WEISS/MANFREDI to house the revered Brazilian landscape architect Roberto Burle Marx’s only extant design in North America—is in the process of having 484 panels of glass installed. This marks a major milestone in the construction process as the completion date for the project draws near.“We are reimagining and rethinking what the garden under glass experience will be for the 21st century,” said Paul B. Redman, President and CEO of Longwood Gardens. “These new glass palaces continue Longwood’s legacy of being one of the world’s innovators in conservatory design and leading patrons of garden and landscape design. Marrying the art forms of architecture and horticulture is fundamentally part of Longwood’s DNA, since our founder Pierre S. du Pont built our first conservatory. This marriage will continue in the new West Conservatory and in the other spaces being created throughout the 17 acres of our core visitor experience. We look forward to welcoming visitors next year for stunning contemporary experiences that continue to awe and inspire.”This sweeping, deeply sensitive transformation of its conservatory gardens is the most ambitious revitalization of the grounds in over a century. The project transforms 17 acres of the core visitor experience, offering a newly unified, continually varied journey from lush formal gardens to views over the open meadows of Pennsylvania’s Brandywine Valley. The Promenade, which stretches along the front of the Main Conservatory and is being expanded to run along the new West Conservatory, is nearing completion. The Conservatory Overlook featuring 28 American Yellowwoods in 2 large lawn panels and 4,600 square feet of precast seat steps overlooking the Main Fountain Garden will open ahead of the rest of Longwood Reimagined in summer 2024 with the return of Longwood’s beloved Fireworks and Fountain Shows. Visitors to Longwood will enjoy a redesigned space and from which to observe these one-of-a-kind shows.Other elements of the $250 million Longwood Reimagined project that have achieved important milestones include the construction of a new education and administration building, named The Grove after the stand of Plane trees the building overlooks. The exterior of The Grove’s 46,000 square foot facility is now complete and interior work has begun on the state-of-the-art library and classrooms. Overlooking the Main Fountain Garden, the 1906 Restaurant and private event space named The Fountain Room, are receiving interior finishes including a molded design on the vaulted ceiling, inspired by the basketweave effect of water produced by the fountains in the Main Fountain Garden.Longwood Gardens is working with the Challenge Program in Wilmington DE, a non-profit that provides training in vocational construction skills to Delaware’s young people. With Longwood, the Challenge Program is creating custom furnishings from fallen hickory, catalpa, and ash trees from across Longwood’s acreage. Longwood’s new restaurant, 1906, will feature hand-crafted solid wood private dining tables, host desk, farm table, and showcase, and The Grove will receive new handmade conference tables.Prioritizing sustainability, 130 geothermal wells have been drilled approximately 350 feet deep and are connected to a ground-source, multi-stage heat exchanger that provides heating and cooling to the administration building, lower reception suite and lower level of the new conservatory. The main level of the new conservatory relies primarily on passive conditioning. Ten earth ducts provide year-round passive tempering of fresh air in the conservatory. The earth ducts are three-foot diameter tubes, 300 feet long, buried under the south slope of the gardens outside the conservatory. Fresh air is drawn into the earth ducts near the Idea Garden. As it is drawn through the earth ducts, it is warmed or cooled by the earth depending on the season. The earth-tempered air is introduced to the space at the pedestrian pathway to provide passive thermal comfort for occupants and visitors. This innovative design means that the building solely uses natural ventilation rather than relying on mechanical cooling during warm months.Horticulturally, custom soil mixes are being prepared for all areas of the project. The vast majority of the 9,000 cubic yards that were saved from the restaurant excavation are being blended with compost on site and will be used in the Meadow landscape. Inside the conservatory, Longwood horticulturists have developed a specialized “mix” of seven different components known to successfully support Mediterranean gardens. The remaining turf and garden areas within the 17 acres of landscape will receive sand-based, high-performance soils to provide well-draining media that will support plant growth.Additional recent landscape milestones include the planting of 765 boxwood in front of the 1906 Restaurant and The Fountain Room as part of a 525-foot-long garden terrace adjoining the Main Fountain Garden. The cultivar, Buxus NewGen Independence®, was selected for its resilient characteristics and its similar appearance and growth to Buxus microphylla ‘Green Beauty’ found in the Main Fountain Garden. In the coming years, the boxwood will be trimmed and shaped by Longwood’s horticulturists to match the billowy shapes of the boxwood throughout the Main Fountain Garden. On the 18-foot-high façade of the 1906 restaurant and The Fountain Room, a trellis is being installed to support 27 espaliered Southern Magnolias set within a continuously flowering herb garden.In the months ahead, a series of courtyard gardens will emerge around the new West Conservatory and The Grove introducing plantings that include 300 trees, 670 shrubs, and some 10,000 perennials. The Meadow will see 70,000 little bluestem plugs planted over almost four acres, framing the West Terrace and creating a connection to the Meadow beyond.

About Longwood Reimagined: A New Garden ExperienceLongwood Reimagined: A New Garden Experience will expand the public spaces of the renowned central grounds of Longwood Gardens 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. 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 glass houses. The project is managed by Bancroft Construction Company, based in Wilmington, Delaware. In keeping with Longwood’s tradition of creating beautiful environments that feature fountains and horticultural displays, the centerpiece and largest single element of Longwood Reimagined is the creation of a new 32,000-square-foot glass house, designed by WEISS/MANFREDI, with gardens and pools designed by Reed Hilderbrand. Longwood’s Cascade Garden, the only extant design in North America by the great Brazilian landscape architect Roberto Burle Marx, is being relocated to an all-new, 3,800-square-foot glass house of its own, a jewel box where the tropical plantings will 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. Other elements of the Longwood Reimagined project include 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 the eventual relocation of six historic Lord & Burnham glass houses from the early 20th century, which will be used for year-round garden displays.

About Longwood GardensIn 1906, industrialist Pierre S. du Pont (1870-1954) purchased a small farm near Kennett Square, PA, to save a collection of historic trees from being sold for lumber. Today, Longwood Gardens is one of the world’s great horticultural displays, encompassing 1,100 acres of dazzling gardens, woodlands, meadows, fountains, a 10,010-pipe Aeolian organ, and grand conservatory. Longwood Gardens is the living legacy of Pierre S. du Pont, bringing joy and inspiration to everyone through the beauty of nature, conservation, and learning. Longwood is one of more than 30 gardens in the Philadelphia region known as America’s Garden Capital.

About WEISS/MANFREDIWEISS/MANFREDI Architecture/Landscape/Urbanism is a multidisciplinary design practice based in New York City. Founded by Marion Weiss and Michael Manfredi, the firm is known for the dynamic integration of architecture, art, infrastructure, and landscape design. The firm is well known for the Seattle Art Museum’s celebrated Olympic Sculpture Park, named by TIME magazine as one of the top ten marvels in the world and by Architectural Record as one the “most significant works that defined architecture in our era.” Other notable projects include the Women’s Memorial at Arlington National Cemetery, the Brooklyn Botanic Garden Visitor Center, and Hunter’s Point South Waterfront Park. The firm’s current work includes the U.S. Embassy in New Delhi, India, the Artis—Naples Baker Museum and Cultural Campus, and the Tsai Center for Innovative Thinking at Yale. Most recently, the firm was selected through an international competition to reimagine the La Brea Tar Pits and Page Museum in Los Angeles.Weiss and Manfredi have won numerous awards, including the 2020 Thomas Jefferson Foundation Medal in Architecture, the Cooper Hewitt National Design Award, the AIA President’s Award, the Academy Award for Architecture from the American Academy of Arts and Letters, and the International Veronica Rudge Green Prize for Urban Design. They have also been named one of North America’s “Emerging Voices” by the Architectural League of New York, received the New York City AIA Gold Medal of Honor, and were inducted into the National Academy of Design. Michael Manfredi is a Senior Critic at Harvard University and Marion Weiss is the Graham Chair Professor of Practice at the University of Pennsylvania. Three monographs on the firm’s work have been published, including most recently Public Natures, and their work has been exhibited at the Venice Biennale, the São Paulo Biennale, the Guggenheim Museum and the Museum of Modern Art. For more information visit

About Reed HilderbrandReed Hilderbrand is the award-winning landscape architecture practice founded by Douglas Reed and Gary Hilderbrand. The firm’s approach seeks to connect daily life with the systems of nature and patterns of culture that together give identity to place. Recognized with more than 80 design awards, the practice is known for its great sensitivity to place and record of design excellence in collaborations with organizations, institutions, communities, and individuals. Among Reed Hilderbrand’s completed works are The Clark Art Institute in Williamstown, Massachusetts; the Besthoff Sculpture Garden at the New Orleans Museum of Art; and the Leventritt Shrub and Vine Garden at the Arnold Arboretum in Boston, Massachusetts. Notable works in progress include commissions for Dumbarton Oaks Research Library and Collection, Storm King Art Center, Tanglewood Music Center, and the American Museum of Natural History, which will open its Richard Gilder Center for Science, Education, and Innovation later this spring. The Architectural League of New York named Reed Hilderbrand one of North America’s “Emerging Voices” in 2005. Douglas Reed is recipient of the 2019 ASLA Design Medal and was a 2011 Resident at the American Academy of Rome. ASLA named Reed Hilderbrand Firm of the Year in 2013. For more information visit

About Bancroft ConstructionBancroft Construction is a Construction Management, General Contracting, Design-Build, Preconstruction, and Virtual Design firm serving the Mid-Atlantic region with offices in Delaware, New Jersey, and Maryland. Centered around bettering communities in which they live and work, Bancroft assists clients with projects from concept to completion while developing long-lasting relationships. Bancroft specializes in construction of facilities in various market sectors, including science + technology, cultural, higher education, k-12, multi-family housing, manufacturing, government, and healthcare. Bancroft has been proud partners in many outstanding projects—including the award-winning Revitalization of Longwood Gardens’ Main Fountain Garden Revitalization at Longwood Gardens (2014-2017). For more information visit