Identifying invasive plant species: what plant propagators need to know about the science behind invasive plant assessment protocols^©

Although only a very small number of introduced plant species ultimately become invasive in the United States, those that do can cause a number of harmful effects within our natural communities. Some of these invasive species are woody in nature (trees and shrubs), and these typically have a past or current horticultural connection. Thus, plant propagators of woody plant species need to remain informed of how plants are identified as invasive and which species are beginning to spread in their state. In this paper, I present additional reasons for why plant propagators should care about this issue, what they need to know about how states assess plant species as invasive, and newer issues involving cultivars that also provide unique opportunities for plant propagators. Ultimately, plant propagators are encouraged to become better engaged with efforts to assess invasive plants in their own state and to contribute to the dialog about invasive plant issues in the United States.