When landscaping with rocks, especially small decorative stones, you’ll want to consider how deep your layers should be. For instance, if you’re going to add a layer of beach pebbles to your rock garden, you don’t want to spread them too thin, but you also don’t want to create poor drainage by having too many. Here are a few depth suggestions when laying down rock layers: • If the stone’s size is 1/2-inch or less, create a 2-inch layer. • Create a 3-inch layer if the stone’s size is 3/4-inch to 1-inch, • If the stone’s size is 1-inch or more, create a layer of 4-inches.