Wolfgang Oehme, a landscape architect who drew from a palette of feathery grasses and black-eyed Susans to create what he called “horticultural explosions,” free-form landscapes that some called exemplars of “the new American garden,” died on Dec. 15 at his home in Towson, Md. He was 81.

The cause was colon cancer, said his son, Roland.

“I like it wild,” said Mr. Oehme (pronounced EHR-ma), describing how he marshaled masses of meadowlike grasses and perennials to evoke the feeling of ocean waves. He called the effect a metaphor for the great prairies of the West.

For 30 years, Mr. Oehme teamed up with James van Sweden to develop self-sustaining gardens, free of pesticides, that could remain beautiful even as the seasons changed. They planted flowers and bushes not by threes and fives, but by the thousands. Details, like how the wind would move the leaves of different plant species, were studied meticulously. Water, whether trickling or in reflecting pools, became a hallmark.

Image Wolfgang Oehme liked to use grasses, perennials and water. Credit... James van Sweden

Their work graced embassies, universities and private homes, including Oprah Winfrey’s. In Washington, it can be seen at the Treasury Department, the National Gallery of Art, the National Arboretum and the Federal Reserve building. In New York, they created pieces of Battery Park City and Hudson River Park. Their work extended to Minneapolis and West Virginia.