Not all river rock installations are the same. Whether you’re spreading river rock as a mulch, pathway, or drainage system, follow the guidelines for your specific landscape project.  Many river rock landscape ideas are easy DIY projects, while others may require a professional for installation.  In some cases, you may want to use landscape fabric beneath the rocks to control weeds and prevent the stones from embedding in the soil. If you place a few medium-sized river rocks beneath a downspout to control drainage, you may not need landscape fabric. If you are spreading river rock around plants, you’ll want to work slowly. Lay down your river rock by the handful, and carefully spread it out around your plants.  Keep in mind: The depth of your river rock layer will vary depending on the rock sizes you’re installing.