The essay has been developed on the occasion of the X Forum ProArch, National Scientific Society of Architectural Design teachers, SSD ICAR 14-15-16, held in Genoa, on 16-17-18 November 2023. The result is a lemmary where the author focuses on “Urban Forestry” as an architectural response to the urgency of reversing the process of transformation of the cities. What does Architecture do when permeable soils and cultivated or wooded areas grow? How buildings help the expansion into the towns of freshness, silence, perfume, beauty, sense of common belonging? Above all in the last twenty years, physical-perceptive systems capable of providing the city with services that, to a common observer, might seem to belong to natural processes have been envisaged. But Urban Forestry does not replicate nature, an impossible objective, but rather reproduces it or emulates some functions. Similarly to Artificial Intelligence, it can actually enhance the creative action of man and contribute to integrating, in qualitative terms, the political response to climate change.