As our climate changes, concern is rising over how plant species will adapt in terms of their geographical distribution (or range). Research has identified conflicting patterns in species performance, especially at the outer edges of their ranges, casting doubt on our ability to accurately predict the impacts of climate change. A study assesses 27 European tree species to identify how populations’ performance can change at their range edges, and how this response differs between the ‘hot and dry versus the ‘cold and wet’ edges of each species.