The use of living plants in slope stability applications represents a bioengineering technique that has gained popularity in recent years. Roots play a crucial role in reinforcing and stabilizing both natural and artificial slopes. This study aimed to evaluate the influence of roots on the shear strength parameters of organic soils and sandy soil. The plants used in this study are commonly used in bio-stabilization methods: Medicago sativa, Dactylis glomerata, Phleum pratense, Trifolium pratense, and Trifolium repens. Several direct shear strength tests were conducted on sandy and organic soil samples both with and without plant roots, and the results are presented in the paper. The roots increased the shear strength parameters of sandy soils by enhancing cohesion. For effective bio-reinforcement, it is recommended to use geosynthetic materials for erosion control, which will ensure the stabilization of plant seeds and roots.