Born in New York City as Lockwood de Forest III, he was known professionally as Lockwood de Forest, Jr. He developed a deep love and knowledge of the California landscape while at the Thacher School in Ojai. Although his professional preparation was brief, de Forest practiced as a landscape architect in Santa Barbara for almost 30 years. His strong regional sensitivity and considerable horticultural knowledge led to major commissions. In addition to estate designs for Val Verde and Casa de Herrero, among the finest of their era surviving today in California, he also worked on Hope Ranch, and enjoyed a long consulting relationship with both the Santa Barbara Botanic Garden and the Santa Barbara Museum of Art.
De Forest, along with his wife and business partner, Elizabeth Kellam de Forest, was especially recognized for bold, theatrical effects accomplished through horticulture, asymmetrical elements within formal settings, and for design work with a strong painterly quality. Together, the de Forests founded and subsequently edited The Santa Barbara Gardener from 1925-1942, combining Elizabeth’s plant knowledge and elegant prose with Lockwood’s knowledgeable commentary on design. They published a range of authors, including Lester Rowntree, Lucille Council, and Florence Yoch.