This study was undertaken to identify occupational areas in the horticultural industry and to identify, describe, and categorize the mental and physical skills needed by workers in horticultural occupations. Competency lists were developed for these occupational areas: arborist services, farm and garden supply centers, golf course management, greenhouse production, landscape services, nursery production, park and highway management, retail florist, and wholesale florist. A survey instrument incorporating the competencies was administered to 1,435 Iowa horticulture employees with a response rate of 36%. Data are presented in two parts. Part 1 contains information relative to occupational areas in each of the nine categories and the number of persons employed in each. Geographic distribution of businesses from which responses were received is also provided. Part 2, covering the majority of document, consists of tables which summarize the competencies performed by workers in each of the nine areas. Data are presented in the two broad categories of management and sales and labor. The tables list the tasks and indicate performance frequency by number of employees and by overall percent of employees. (NJ)