Urban grasslands cover large land areas in human-dominated landscapes, but little is known about how these landscapes cycle carbon (C). In this study, we examine turfgrass biomass and productivity at thirty-three urban grassland sites within the Gwynns Fall watershed (Baltimore, MD). These sites are characteristic of residential conditions in the region and were selected to provide contrasts in urban ecosystem structure (density of coarse vegetation and built structures) as well as historical (pre-development) land use. Aboveground net primary productivity (ANPP) was measured as the sum of clipping production plus stubble, thatch, and moss production. This work provides context for understanding the impact of urban expansion on regional ecosystem C dynamics and identifies specific needs related to standardized methods for measuring turfgrass ANPP in urban grassland systems.