Of 311 papers on wetland restoration, only 15 concerned large-scale experimentation in restoration sites. Most papers described what happened, reported on small field experiments, or discussed restoration targets. While these are important topics, our opinion is that we lose significant opportunities to learn how to recover populations, community structure, and ecosystem processes, and we limit our ability to document variability and whole-system responses, when we do not experiment at large scales. We suggest that, wherever possible, large projects facilitate field tests of alternative restoration approaches. Furthermore, we encourage researchers to take advantage of major restoration efforts by conducting large field experiments, assessing multiple responses, and offering restoration guidance in an adaptive framework.