Integrated solutions to the climate and biodiversity crises—together with other global sustainability challenges—include the identification, design and implementation of nature-based solutions (NbS). Living organisms mediate biogeochemical cycles and greenhouse gas fluxes from land and sea, and provide NbS to both climate change mitigation and adaptation. Plants, as the primary producers in ecosystems, lie at the heart of NbS. Plant ecology provides the foundation for developing and evaluating NbS based on an understanding of the ecological processes that underlie ecosystem service flow to people. In this Special Feature, we provide a collection of mini-reviews that presents concise and focused analysis of the plant ecology of NbS. The mini-reviews highlight key insights, challenges and opportunities for future research. The development of NbS that target specific ecosystem functions (e.g. carbon storage), or aim at increasing ecosystem resilience against perturbations (e.g. those associated with climate change), requires unification of ecological theory from areas such as biodiversity-ecosystem function, plant–animal interactions, resilience and functional traits of organisms. Synthesis. Plant ecology and nature-based solutions (NbS) research are complementary. Plant ecology can inform the design and management of effective NbS, and provide insights for the creation of novel ecosystems that provide NbS; while learning from the implementation of NbS can progress theory. To deploy NbS at the speed and scale needed to mitigate and adapt to climate change, we must rapidly integrate ecological concepts into the design of NbS. At the same time, the design and deployment of NbS in different ecological contexts provides an unprecedented opportunity to learn how performances of individual NbS sites can be explained in an integrated way, leading to the development of general concepts. Ultimately, a mechanistic understanding of how plants and their functional traits contribute to ecosystem function and service provision is critical for the design, verification of benefits from and avoidance of adverse effects of NbS.