Located within a protective greenhouse on the western end of Longwood Gardens’ 4.5-acre conservatory complex, this 2,000-square-foot garden designed by Roberto Burle Marx opened in 1993. Measuring only 40 by 50 feet, the area was once the location of the Desert House, many plants of which were incorporated into the Silver Garden. To create the Cascade Garden, Marx collaborated with his longtime friend and protégé Conrad Hamerman. Although the garden is relatively small, it conveys a strong sense of verticality, incorporating the steel columns that support the neighboring Rose House into its design.
Burle Marx emphasized the verticality of the diminutive space by encasing the steel structural columns in wood frames and covering them with halved tree-fern trunks. The walls of the garden were made from a special blend of shredded tree fern, vermiculite, and cement, all dyed to give a natural appearance. The illusion of increased height was further achieved by sixteen waterfalls that cascade into four pools. Resembling a South American rain forest, the garden contains more than 150 varieties of tropical plants, including a wide range of bromeliads—aechmea, giant alcantarea, orchids, ferns, elephant ears, and others. Some 35 tons of Pennsylvania mica were mined from local quarries to create the flowerbed’s retaining walls, which follow the winding pathway through the space. The vibrant yellow, red, and orange plants within the ground-level flowerbeds partially climb the walls. Fog emitters placed throughout the room maintain a constant humidity level of 80 percent, spraying fine mists to emulate the South American climate. Longwood Gardens was listed in the National Register of Historic Places in 1972.