The third and final series event in late September will celebrate the opening of a new garden at Cornerstone by the landscape architectural firm of Oehme, van Sweden & Associates of Washington, D.C., with the appearance of horticulturist and landscape architect James van Sweden and sculptor Grace Knowlton.

Since their partnership in the 1970's, Van Sweden and Oehme have become known for innovations in landscape design that have filtered down to many of our backyards and gardening styles.

On a small scale, we think of habitat gardening, but on a larger scale, which is van Sweden's forte, the approach is known as the New American Garden style. It's definitely a modern method, but it's also a throwback of sorts to natural forms, especially the meadow. Conservationists and ecologists identify with the New American landscape philosophy of creating a four-season garden scene that requires little water or maintenance, restricting pesticides and fertilizers, and selecting plants-particularly perennials and grasses-that are suited to a site.

Quite the opposite of modernistic landscapes devoid of flowers or foliage, the Oehme and van Sweden gardens are filled with spectacular plants, many in flowing masses intended to harmonize with nature. Instead of stylized forms, their influential designs allow plants to dominate, often woven against a background of taller trees and shrubs, water, walls and terraces.

To register for these events, which include a garden reception with the speakers, visit or call 415-561-7895. For more information on the Cornerstone Festival of Gardens, see