The 18 new “supertrees” in Singapore’s Bay South garden are gigantic trellises for exotic plants, but they also double as exhaust tubes and supports for sustainable infrastructure.

The brightly colored concrete and steel structures rise at varying heights up to 164 feet, and support some 200 plant species including orchids, neoregelias, and bougainvilleas. Eleven of the towers will support photovoltaic cells and rainwater harvesting technology, while also venting warm air from the underground cooling system of adjacent conservatories. A 420-foot-long aerial walkway will link two 138-foot-high supertrees to give visitors a bird’s-eye view of the gardens, and the tallest will house a restaurant in its “canopy.”

The $831 million Bay South garden is the largest of three gardens wrapped around a freshwater reservoir in a mixed-use business and residential development called Marina Bay (perhaps best recognized for the architect Moshe Safdie’s three high-rise buildings connected by a gigantic floating deck in the air). The community is pa1t of the Gardens by the Bay development, which stands on about 250 acres of reclaimed land on Singapore’s south coast. Master planned by Grant Associates and Gustafson Porter, both British landscape architecture firms, it features two conservatory domes, 12 themed gardens, and a two-mile-long waterfront promenade.

The garden layout for Bay South is based on the shape of the national flower of Singapore, an orchid hybrid called Vanda Miss Joaquim var. ‘Agnes.’ Andrew Grant, of Grant Associates, says the giant karri trees (Eucalyptus diversicolor) in Australia’s Walpole-Nomalup National Park were another source of inspiration. The karri trees “loom over the surrounding forest to create an extraordinary sense of scale and drama,” he explains, and he set out to design something similarly impressive.

The gardens will open for an advance viewing as part of the 20th World Orchid Conference in November [2011] and are scheduled to open to the public next summer.

www.gardensbythebay.org.sg/