Many studies track the geographic spread of invasive plants, but little is known about how such species may expand their ecological range (the range of environments in which they can successfully establish populations). Developing approaches to track ecological range over time could substantially contribute to understanding invasion dynamics. In a recent study published in AoB PLANTS, Matesanz et al. document a significant expansion over a 15-year period in the range of light and moisture conditions inhabited by the Asian annual Polygonum cespitosum in northeastern North America. The species’ increased ecological breadth is coincident with its more aggressive spread in the region.