Researchers and practitioners have been aware of the importance of plant diversity for many decades. The Irish potato famine and dutch elm disease (Ophiostoma novo-ulmi) are examples of problems resulting from lack of diversity. Emerald ash borer (Agrilus planipennis) has renewed concerns over these issues, yet little has been done to increase diversity in landscape plantings. Urban trees are becoming more uniform genetically because of cloning of preferred cultivars; thus, they are losing potential resiliency to stresses at a time when these threats are increasing. A survey on plant diversity distributed to wholesale nurseries in Washington State showed that most respondents were aware of the issues, but lacked an in-depth understanding of them. This article presents additional data from the survey. Respondents reported that lack of consumer demand was an issue. Those with more education exhibited a deeper understanding of the risks from low diversity among landscape plants. Instructors in horticulture and the plant sciences should be more involved in teaching on this topic.