For many centuries, man has been concerned with stabilizing soils in order to either prevent them from being easily eroded or to make them better suited for construction such as for earth building and road construction purposes. Attempts have been made to utilize many natural, synthetic or waste materials for such soil stabilization. Plants have been used as soil cover to prevent erosion and protect slopes. However, there is need to evaluate the engineering characteristics of soils reinforced with plant roots. Consequently, this research work was aimed at investigating the effects of the reinforcement of a landslide-affected soil using the roots of a locally-available plant on the strength and permeability properties of the soil. The natural moisture content, specific gravity, particle size distribution, Atterberg limits, compaction characteristics, shear strength, unconfined compressive strength (UCS) and permeability of the natural (landslide-affected) soil were determined. Results obtained for the natural landslide-affected soil were compared with those of the soil sample admixed with varying proportions (1%, 2%, 3% and 4%) of lemon grass roots. The result shows that the shear strength and UCS of the soil having 4% lemon grass roots is almost double that of the natural soil. Also, the permeability of the soil-root matrix was sufficiently reduced. Planting lemon grass on soils located along slopes is recommended to improve its strength and minimize the ease with which water infiltrates the soil, thereby reducing the incidence of landslide and other water-induced types of slope failure.