The most acceptable way to prevent and eliminate negative phenomena arising from devastating landscapes is phytomelioration. To assess the suitability of the landfill's surface for phytomelioration measures, it is necessary to determine the species composition, physiological stability, density, and completeness of the tree stand (in case of the tree species development) already developing as a result of natural overgrowth. The present work examines the ecological succession of three large urban landfills within the Western Forest Steppe of Ukraine - Lviv, Ternopil, and Lutsk. It was established that the maximum phytomass is characteristic of the gentle slopes of landfills with relatively stable moisture index, and developed soil, which gives reason to attribute the plant groups to the endoecogenesis stage while there are no garbage dumping processes. Three stages of overgrowth were identified for all landfills – syngenetic succession, initial endoecogenetic succession, and mature endoecogenetic succession. The taxonomic structure of the flora of the urban landfills of the Western Forest Steppe is represented by the divisions Magnoliophyta, Pinophyta, Polypodiophyta, Bryophyta, and the classes Magnoliopsida, Liliopsida, Pinopsida, Equisetopsida, Polytrichopsida. The phytomeliorative efficiency of vegetation at solid waste landfills shows that the surface of landfills in the Western Forest Steppe is dominated by stunted plants and the phytomelioration coefficient is low. Thus, the surface of the landfill is suitable for phytomelioration and reclamation works and landfill decommissioning. The phytomeliorative efficiency of vegetation at solid waste landfills shows that the surface of landfills in the Western Forest Steppe is dominated by stunted plants and the phytomelioration coefficient is low. Thus, the surface of the landfill is suitable for phytomelioration and reclamation works and landfill decommissioning.