Coastal regions are one of our planet earth’s most important geographic features. Erosion and accretion are the two major phenomena that affect coastal areas, especially with extreme events of precipitation. Both change the shoreline permanently. This work comprises the experimental analysis to assess the ability of plant species to reduce the erosion of soil. The experiments were conducted on typical laterite soils, and a native coastal soil of Kerala, collected from Dharmadam Beach, Thalassery, planted with vetiver grass with different geometrical arrangements. Artificial rainfalls of intensity 150 mm/h were simulated, and the extent of erosion was measured in terms of weight of soil collected in runoff water. It was observed that the erosion of coastal soil and the laterite soil could be largely controlled with vetiver plants. The optimum spacing for vetiver planting was observed as 15 cm × 15 cm in the case of both soils. The tests were repeated with repetitive incidents of artificial rainfall to confirm the optimum spacing. The study helps substantiate the role of vetiver plants in coastal erosion control practices. So, it was established that a vetiver soil system can protect the slopes from heavy rainfall-induced soil erosion and slope failure at a small depth if planted at an optimum spacing of 15 cm.