Whether they are growing, shrinking, or just standing their ground, cities throughout the United States are looking for ways to reinvent and reinvigorate their urban landscapes. More and more, planners are employing urban greening strategies as tools to enhance the quality of life and create more sustainable metropolitan environments. This is especially true in places that have suffered the consequences of deindustrialization and economic decline over the past 50 years. This paper begins by briefly discussing the evolution of urban greening and the vast array of associated benefits. It then examines expanding efforts to use brownfield sites as opportunity spaces for greening, focusing on project types, planning activities, stakeholder involvement, and redevelopment outcomes. The paper ends with some key lessons from the field that can help planning professionals realize a greener future for our nation’s cities.