Motorway slopes cover large areas and could, if properly managed, partially compensate for the loss of natural habitats and connect remnant populations of target species. One of the main problems on such slopes is soil erosion; therefore, quick and stable revegetation is essential. Two widely used commercial seed mixtures were sown and tested to determine which one is better for restoration of motorway slopes. Both mixtures contained CSR strategists ("competitive stress-tolerant ruderals") but one included nurse species (Lolium perenne, L. multiflorum, Trifolium spp.), whereas the other did not. Both treatments were sampled every year over a period of 6 years and analyzed for species richness, diversity, similarity, and plant cover. The research took place in the sub-Mediterranean part of Slovenia, where low precipitation during summer is characteristic. It was found that the seed mixture with stress-tolerating species but without nurse species resulted in a smoother succession to a species-rich grassland with stable cover. Succession was, by contrast, delayed in the mixture with nurse-plants because they inhibited the establishment of the stress-tolerating species and target species, respectively.