The landscape plant materials informational needs of planting designers were evaluated in a historical and contemporary context. It was found that plant designers need to know about the environmental and cultural adaptation, landscape value and use, and commercial availability of the plant materials that they use. Surveys of regional plant materials experts and nursery inventories were made to determine which plants should be included in a reference text. The climate of the region is also identified and compared to other parts of the country. Plant materials reference books were reviewed to see if they provided this information for plants grown in the Intermountain region. These reference books were found to be inadequate for professional landscape architectural use in the region. A proposal for a plant materials reference handbook is made and individual plants to be included are selected.