In a highly structured environment, as an urban centre, there are impacts for both humans and the environment. The urban heat island effect and energy poverty are impacts of this situation. A common way to deal with the last two impacts is to reduce the temperature by using bioclimatic design. This research is the subject of a project at the Technical University of Crete about the use of urban gardens as a way to reduce the air and surface temperature in Chania, and more specifically in the district of Chalepa. The threats to biodiversity and the idea of urban gardens are presented. In this research, a scenario with absence of vegetation, the current state and two scenarios with different vegetation in urban gardens are analyzed. The first scenario involves horticulture species and the second one the cultivation of aromatic and medicinal species. These scenarios were examined using the numerical model Envi-met after the collection of data needed such as the height of buildings, vegetation characteristics, the location of the area etc. Finally, the scenarios of urban gardens decreased the surface temperature by 10 °C from the scenario with absence of vegetation and 5 °C from the current state in days of high temperature. However, the differences between these two scenarios were not of great importance.