The Invaders of Texas program is a successful citizen science program in which volunteers survey and monitor invasive plants throughout Texas. Invasive plants are being introduced at alarming rates, and our limited knowledge about their distribution is a major cause for concern. The Invaders of Texas program trains citizen scientists to detect the arrival and dispersal of invasive plants in their local areas and to report them into an online, statewide mapping database. In order to test the value of citizen scientists' data, we compared Invaders of Texas citizen scientists' observations of "Arundo donax" (giant reed) with previously recorded "A. donax" observations in Texas and found an increase in the reed's overall distribution. A comparison with observations from the Invasive Plant Atlas of New England, a similar citizen science program, confirmed that, given proper training, citizen scientists are able to detect and report invasive plants in their local areas, and the data they collect can be used by professional scientists.