In low-income communities, schools often lack the resources to provide children with robust, hands-on science experiences, especially those that utilize green spaces and natural phenomena outside their doors. Out-of-school-time programs are well-positioned to fill this gap, but to do so must address constraints that prevent educators and parents from being able to support children's engagement with science. This paper presents findings from an NSF-funded initiative to examine these constraints and evaluate how a multimedia Toolkit may address them and engage urban youth and families in fun, physically active science exploration. The study, conducted in 10 urban settings, demonstrated the need for resources of this kind, and showed the Toolkit engaged children and fostered science teaching and learning in informal settings.