Urban Open Spaces (UOS) are green infrastructures that provide social and ecosystem services. Green public areas contribute to mitigation and adaptation strategies for addressing climate changes, but their maintenance has a significant cost. Frequent grass cutting operations must be carried out during growing periods to ensure the safe livability of UOS to citizens. In the present paper, a geo database was developed to map green public areas of the city of Latina (Lazio Region, Central Italy) by using a multisource dataset according to the European INSPIRE Directive. The GreenCAL Tool was implemented. Two algorithms to determine UOS extension and the necessary budget for grass cutting operations are used, considering the contribution of different mowing (i.e., mulcher, lawnmower, or brush cutter) and UOS extension itself (~160 ha). The implemented processing chain allowed us to simulate forestation of abandoned areas and potential CO2 sequestration values. Two different scenarios of maintenance programs were also implemented to reduce more than 60% of operational cost according to: (1) different use of UOS; (2) their position within the urban area; (3) guidelines of Italian working group on public green management; and (4) management of vegetal residues. The management of the latter, derived by mowing, contribute to more than 23% of the budget allocated to maintain UOS. Besides the long-term environmental and health perspective, the short-term impact of the present applied research is relevant for a geomatic approach, green public procurements, as well as land use and climate interactions. The alternative management of UOS discussed in the present paper can also reduce organic waste production if the mowing within the UOS is managed as a resource for agriculture rather than urban waste.