Plants introduced through ornamental horticulture have contributed to exotic species invasions around the world. Fifteen landscape plants commonly used in horticulture in southern Arizona have been evaluated using the Plant Risk Evaluator (PRE) tool developed by PlantRight and Cal-IPC. The evaluations have recognized eight of these species as presenting high potential risk of escaping cultivation and becoming invasive in Arizona. The process of evaluating ornamentals has fostered communication and collaboration between invasive species managers and Extension horticulture agents, who previously had little interaction. The findings have been communicated through several articles on invasive species in the trade magazine, Southwest Horticulture. This information has contributed to two cultivated species (Searsia lancea and Ulmus pumila) and the entire genus Tamarix being newly added to the Arizona State Noxious Weed List. Arizona Master Gardeners have been educated on invasive plant issues to foster outreach to the public and to aid their planting choices.
