Invasive non-native plants can cause considerable environmental damage by replacing native species and altering ecosystem processes. Managers frequently respond to this threat by spraying herbicides, which is relatively inexpensive and requires less human labor than other control options. However, the long-term efficacy of this practice, its non-target effects on native plants, and its role in facilitating secondary invasions are not well understood. Furthermore, data on herbicide usage is rarely tracked although it is crucial for policymakers, researchers, land managers, pesticide producers and the general public. Here, I report on research projects that used greenhouse and field experiments in the foothills grasslands of Montana and (1) examined the long-term efficacy of herbicides in controlling an invasive non-native forb, (2) investigated the non-target effects of herbicides on native plant communities and plant germination, and (3) tested whether herbicide usage facilitates secondary invasions. Furthermore, I report on the results of a study that (4) quantified h