We hypothesized that soil disturbance was required for black henbane establishment.  To test this hypothesis we established four ecosystem disturbance treatments, designed to separate plant competition from soil disturbance.  We quantified changes in soil properties, henbane success and the native plant community response due to different disturbance types.  Our results indicate henbane was unable to invade undisturbed communities in sagebrush, shortgrass and mixed grass ecosystems; however, soil disturbance was not required, as henbane successfully invaded treatments with competition removal only.  This establishment and survival pattern appears to be strongly correlated to higher rates of available nitrogen, soil moisture and possibly potassium.  Greenhouse studies are underway to confirm this correlation.  These results indicate that while henbane may successfully vector along disturbance corridors, it is not likely to become a major problem in intact sagebrush, mixed grass or shortgrass plant communities.