Technical Abstract: A species’ successful invasion into a new site depends on its ability to persist in the local environment. Thus, knowledge of environmental limitations on growth and reproduction will provide a mechanistic understanding of the invasion process and lead to practical management solutions. We conducted an experiment to examine the response of Arundo donax L. (giant reed) to intermittent periods of shading for three years. Results indicate that A. donax tolerated significant shading (i.e., 90% reduction of full sun) and, that shading also caused changes in a number of plant characteristics, such as stem height, internode length, leaf nitrogen, leaf chlorophyll content, specific leaf weight, total leaf area per plant, and leaf lifespan. Arundo donax’s ability to persist and grow under intermittent low light conditions implies that plants would be poised to take advantage of sun flecks and disturbances that create gaps within the resident plant community.