Smith was born in Waukee, Iowa, and attended Iowa State University, where he graduated with a Bachelor of Landscape Architecture in 1976. After graduation, he apprenticed with sculptor Paul Shao, and worked for the Iowa Conservation Commission in Parks and Recreation Planning. He attended the Harvard Graduate School of Design, and received his master's in landscape architecture in 1986.
After working in the office of Peter Walker and Martha Schwartz, he opened his own office in New York City in 1992. Smith is active as an educator, teaching as an adjunct professor at the City College of New York from 1992 to 1996, and as a visiting design critic at the Harvard Graduate School of Design from 1997 to the present.
Smith is a board member of the Architectural League of New York and is active in advocating preservation of modern works of landscape architecture.