This article studies the phenomenon of partial exploitation of public gardens in the city of Biskra (Algeria), which is characterized by a hot and dry climate, where most of its inhabitants seek public places to sit, rest and relax to protect from heat especially in summer. The aim of the study is to investigate the problem of partial use of green spaces by users, and the effect of vegetated landscape choices. The study was based on a quantitative measurement of the effect of plant cover on thermal comfort in open spaces (public gardens) by carrying out a numerical simulation using the ENVI-met program "27 and 28 June" of the hottest months in Biskra, in Measurement of air temperature, relative humidity, wind speed, PMV, diffuse solar radiation and direct solar radiation; In addition to on-site experience during selected typical days in digital simulation; It measures the air temperature, the relative humidity and the wind speed were measured using an instrument (Testo 480), then the results were compared between the current situation of the garden and its proposed state of reforest its deserted areas, in order to create a favorable environment for full utilization. This research can give architects and landscapers a way to create public gardens, by controlling the percentage of their plant cover by choosing local trees, and plants that are resistant to climatic factors for their climate and by achieving thermal comfort.