Good discussion to be involved nowadays. We need to regenerate our urban areas to make it a better place for the lives of increasing urban population. In this regard, I would like to pay your attention to two recently published papers dealing with urban greening and its impact on the development of soil organisms and processes.
I'd say Tactical Urbanism is certainly a meritorious way to go. Less top-down and more bottom-up. It is also important to note that de-statisation is real and this has strong implications when we refer to public funding to regeneration investments.
See Tactical urbanism: Short-term action for long-term change, by Mike Lydon and Anthony Garcia, 2015.