Fig. 1. Urban greening projects should anticipate challenges and plan to work collaboratively with stakeholders to address them.

Post-industrial cities such as Cleveland, Ohio, USA face the significant challenge of managing thousands of vacant lots (i.e. parcels where pre-existing structures have been torn down and replaced by minimally-managed vegetation) (a). Although typically viewed as blight, these sites do offer opportunities to conserve urban biodiversity. In 2014, the Gardiner Laboratory established 64 conservation habits on vacant land across the city of Cleveland, including 32 sites seeded with native perennial wildflowers (b). Our cost to establish the 32 pocket prairies was approximately $2500 per site and included soil preparation, seeding, invasive plant management, and installing ‘cues to care’¹¹ such as fencing and mulching. Maintaining cues to care required substantial time and financial investment. Trash, furniture, appliances, and other refuse are frequently dumped into urban lots and must be removed (c). Vandalism to signs, fencing, and vegetation is also common, especially in the springtime when native plantings have not bloomed yet and sites can appear weedy and unkempt (d). Similar aesthetic concerns can happen during the winter. Thus, it is imperative to work with local stakeholders to identify what design modifications can indicate year-round investment into a conservation site. For instance, greenspace managers at the Sunflower+Project: STL, in St. Louis, Missouri, partnered with local elementary schools to paint sustainability flags which hung above their over-wintering sunflower fields (e). However, even with substantial investment, vacant lot ecosystem management can remain a controversial endeavor. Although many residents view rain gardens established though a multi-million USD investment by the Northeast Ohio Regional Sewer District as valuable storm water management, others see a poor use of funds that raises health and safety concerns⁴ (f). Thus, we must work with urban residents and municipal governance as community developers to meet the needs of the diverse human ecosystem. Photograph E courtesy Richard Reilly.