Behavioral interventions that address other-regarding motivations (i.e., other-regarding interventions) are gaining momentum as promising tools to stimulate household recycling. However, previous studies have shown considerable variability in the impact of such strategies, and the factors that moderate treatment effects remain poorly studied. Using a field experiment with 7195 households in Quzhou, China, this study investigated treatment effect heterogeneity systematically based on intervention types, treatment durations, personal motivations, and social networks. Three strategies were examined, including biospheric and altruistic appeals and personalized normative feedback. We found that normative feedback outperformed other strategies in inducing household participation in recycling, that the influences of all strategies attenuated over time, and that the feedback effect was greater among recipients with weaker biospheric or altruistic concerns and those embedded within stronger neighbor networks. However, no significant treatment effects were found on the amount of waste recycled. These findings improve the understanding of the heterogeneous impact of other-regarding interventions, with important implications for the design of recycling policies. Future studies need to explore additional moderators and the effects of treatment combinations.