["Business Strategy and the Environment, EarlyView. ", "\nABSTRACT\nThis article analyzes the dynamic function of green human resource management and sustainable marketing practices in shaping organizational environmental performance across the United States. The mediating role of organizational green culture is investigated by comparing its impact across time points. Using a longitudinal approach, this study captures the dynamics of relationships over time. Data were collected from four organizations in the United States over 12 months, in four successive phases, employing hierarchical modeling to account for nested data and time‐lagged effects. A random forest was also applied to identify the most salient predictors of OEP and to estimate their relative weights. Results confirm that OEP is significantly enhanced by green marketing and GHRM and that organizational green culture is a high‐impact mediator. In time‐lagged analysis, the magnitude of these relationships increased with the lag, suggesting cumulative organizational and behavioral adaptation. Machine‐learning findings were consistent with statistical findings, with organizational green culture and GHRM identified as the leading features. This paper introduces a novel combination of longitudinal, hierarchical, and machine‐learning techniques to estimate both statistical significance and predictive value, providing strong evidence for the development of environmental sustainability in organizational contexts across the United States.\n"]