Rural areas have been subjected to a strong pressure of urbanization which reorganizes landscape mosaics in creating new ecological interfaces: garden/fallow land. These latter are the place of specific floristic dynamics through the movement of cultivated plants from garden to neighboring habitat. In order to understand these ecological processes, the pool of cultivated plants was firstly characterized in Mediterranean gardens. Then, the escaped garden plants and the factors explaining their presence in post-cultural fallow lands were identified with a spatial analysis of two hierarchical levels: the local structure of fallow lands is related to a well adapted pool of escaped garden plants to the Mediterranean climatic and edaphic constraints. The species richness of escaped garden plants in fallow lands was also mainly associated with four landscape variables (41%) corresponding to the proximity and the density of gardens and the openness of landscape around the fallow lands. The dispersal process occurs mainly over short distance. Three local factors related to vegetation structure and topo-edaphism conditions explain 4,8% of total variation. The set of these results highlight that in urbanized landscapes garden plants dynamics are more determined by the composition of landscape through the organization of introduction sites than ecological conditions within establishment sites.