Their gardens were designed with loads of perennials and ornamental grasses, minimal lawn (if any at all) and were always maintained without the use of chemicals and pesticides.
Their first book, Bold Romantic Gardens: The New World Landscape of Oehme and Van SwedenIn a profile of van Sweden that I wrote a few years ago for The American Gardener magazine, architect William McDonough said one of van Sweden's great strengths as a designer was that he understood "the poetry of the landscape." He added that the duo's unique, "painterly" style was more or less the equivalent of Frank Gehry in architecture.
Van Sweden himself said he'd been heavily influenced by Brazilian artist and designer Roberto Burle Marx during a three-week visit to Brazil in 1987. It inspired him, he said, to pursue the "art" of landscape design.
In his final book, The Artful Garden: Creative Inspiration for Landscape Design (Random House, 2011), van Sweden explains how gardens can be inspired by music, by dance, by paintings, sculpture, and all the other fine arts. You can see the kind of "art" he practiced in many public gardens. In Washington DC, the gardens at Ronald Reagan National Airport are akin to the hanging gardens of Babylon. Look at the landscapes around the Federal Reserve Building and the World War II Memorial in DC, the Chicago Botanic Garden, or Nelson A. Rockefeller Park in Manhattan. And the next time you see a swath of grasses waving in the wind, you'll know its the legacy of Oehme van Sweden.
Other books by James van Sweden:
Architecture in the Garden (Random House, 2002)
Gardening with Nature: How James van Sweden and Wolfgang Oehme Plant Slopes, Meadows, Outdoor Rooms & Garden Screens (Random House Gardening Series)
(1997)
Gardening with Water: How James van Sweden and Wolfgang Oehme Plant Fountains, Lily Pools, Swimming Pools, Ponds... (Random House, 1995)
And see more of their work at the Oehme van Sweden website here.