KENNETT SQUARE — Longwood Gardens has announced major project updates about “Longwood Reimagined: A New Garden Experience,” which will open in the fall of 2024.
The centerpiece and largest single element of Longwood Reimagined — a 32,000-square-foot glass house 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 two 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.
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, Del., a nonprofit 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 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 3-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.
