Station scientists investigated perception of risk among nonindustrial private forest owners in Oregon's ponderosa pine zone regarding invasive plants. They found that 70 percent of surveyed landowners were concerned about invasive plants, and 46 percent had treated invasives on their land. Owners' perceptions of invasive plant risks fell along a spectrum, ranging from a lack of awareness or concern, to the view that invasive plant infestations have discrete causes and controllable consequences, to the perception that incursions by invasive plants have diffuse causes and uncontrollable effects. Awareness or concern about invasive plant species were predictors of whether owners treat their parcels to control invasive plants. Holding wildlife habitat or biodiversity as an important forest management goal was also a predictor of whether owners treated their parcels to control invasive plants. Some owners were sensitive to the risks of invasive plant infestations from nearby properties, and a surprisingly high percentage of respondents had cooperated with others in forest management activities previously. These findings suggest three promising approaches to increasing the frequency of invasive plant mitigation by private forest land owners: (1) raise awareness and concern about invasive plants and their impacts on forest management goals that owners care about; (2) provide assistance to help owners mitigate invasive plants they feel unable to control; and (3) engage owners in coordinated efforts across ownership boundaries to address invasive plant risks.