Born in Iowa, Hoyt earned a B.S. from Iowa State and spent two years studying in the landscape architecture department at Harvard University. After working for Olmsted Brothers on the Palos Verdes project in California, Hoyt opened his own landscape architecture practice in San Diego in 1928. Hoyt’s early projects include Muirlands and Presidio Park, the site of California’s first mission and a Spanish fort. Hoyt collaborated on the landscape design for Presidio Park with San Diego philanthropist George Marston and Park Supervisor Percy Broell, under the guidance of John Nolen, who had been retained to create a long-term city plan. From 1943 until 1947, Hoyt was a member of the San Diego Park Commission, after which time he served as the consulting landscape architect for San Diego’s Mission Bay Park. In 1960, Hoyt designed the landscape for Louis Kahn’s Salk Institute campus.
Hoyt was active in the profession as a landscape architect, writer, editor, and as one of the founding members of the San Diego chapter of the American Society of Landscape Architects, to which he was elected a fellow in 1964. Over the course of his career, Hoyt compiled information about the requirements and performance of hundreds of plant species. This reference, the Checklists of Ornamental Plants for Subtropical Regions, is still in use today. Hoyt also served from 1938 through 1944 as the editor for California Garden to which he contributed for many years.