As known, marine dredged materials (DMs) are highly nuisance wastes if they are not correctly reused or removed. In this work, the usability of DMs to the technical terms as manufactured topsoil (MT) in the urban landscaping works is discussed. Firstly, the leaching potentials of DMs were determined according to the related legislations to identify their hazardousness features. Secondly, DMs were subject to some treatment stages such as sieving, desalination, organic amelioration via peat and sheep manure, and pH adjustment to turn into an alternative natural soil pursuant to the British Standard in the scope of soil quality improvement studies as there is not any national standard in Turkey for the production of topsoil from different materials. Then, MT mixtures were prepared with washed and unwashed DM, peat and sheep manure in different mixing ratios (v/v); 33%, 50% and 67% DM, respectively. Consequently, high quality grass seed mixtures used for the landscaping applications were monitored for six months. The results demonstrate the availability of DM as alternative MT in the urban landscaping areas. Thus, important data were obtained as to the use of DM at alternative areas such as green city, green roof, shopping centers, organized industry, etc.