Son of a nurseryman, Haag was born in 1923 in Kentucky, and studied landscape architecture at the University of Illinois, Urbana-Champaign where he met Stanley White and Hideo Sasaki. Transferring to the University of California, Berkeley, he worked summers for Sasaki, receiving his Bachelor of Landscape Architecture in 1950. He earned a Master of Landscape Architecture from Harvard’s Graduate School of Design in 1952, working for Dan Kiley the summer before. His Fulbright Scholarship sent him to Kyoto for two years, and subsequent design work displays influences from this period.
After two years working for Lawrence Halprin in San Francisco, Haag established his own practice. In 1958, Thomas Church recommended Haag to found the landscape architecture department at the College of Architecture and Urban Planning, University of Washington. As a teacher and designer, Haag emphasizes direct contact with sites and informed intuition. Deeply committed to ecological precepts, he has also expressed interest in the social and psychological impact of a site.
Of his more than 500 projects, the two most prominent are Gas Works Park on Lake Union in Seattle and the Bloedel Reserve on Bainbridge Island in Puget Sound. At Gas Works, Haag embraced the site’s industrial history and embarked upon the country’s first public soil remediation experiment. Haag is the only person to have received two Presidential Awards for Design Excellence from the American Society of Landscape Architects. Haag continues to practice, teach, and lecture internationally.