Yes, adding rocks to soil can indeed help improve drainage. Rocks, particularly small ones, can create additional pathways for water to flow through, which in turn aids in preventing water-logging and promotes better soil drainage. This is especially beneficial for plants that require well-drained soil to thrive. However, it's important to note that simply adding rocks to the soil might not be enough in some cases. The type of soil, the size of the rocks, and the specific needs of the plant should also be taken into account. It's always recommended to understand the specific drainage needs of your plants and to adjust the soil composition accordingly.