Promoting nature-based solutions requires that we understand the key challenges and opportunities that are facing projects on the ground. Any innovation has to go on a journey - from the initial idea and its demonstration, to its wider uptake within policy, industry and society. Along this journey, getting the assessment of the value of nature-based solutions, the business models required, and the governance strategies that can support their uptake will be critical. To break the dominance of grey infrastructure, new approaches are needed for the development, implementation and mainstreaming of nature-based solutions.