Born in Chino, California, Hanson completed just two years of high school before going to work for a British Columbia developer. In 1914 he returned to the U.S. where he worked for California plant expert Theodore Payne in Los Angeles. Inspired by the 1915 Panama-California Exposition, Hanson apprenticed with Paul J. Howard with the intent of becoming a landscape architect. After serving in World War I and with no formal landscape architecture education, he opened an independent design-build landscape firm with offices in Beverly Hills and Hollywood. As his practice grew, he began accepting commissions for large estates and parks, one of the first of which was actor Harold Lloyd’s Greenacres estate designed in 1925. A tour of Europe in 1927 influenced his style and added a level of sophistication to his designs, which is reflected in his Country Place Era gardens including La Toscana (now Sotto il Monte) and the Archibald Young garden. During the Depression years Hanson maintained his practice with civic work, designing Doheny Memorial Library landscape at University of Southern California. He joined the Palos Verdes Corporation as General Manager in 1932. There he collaborated with Charles H. Cheney to create a scenic highway encircling the Palos Verdes Peninsula. Palos Verdes led to more development work with planned communities, including Rolling Hills and Hidden Hills, where Hanson’s aesthetic evolved to embrace the creation of informal modern California gardens for suburban communities. Hanson authored two books about his work.