Mulching around plants and trees is a good way to hold moisture in the soil and keep the topsoil from eroding from wind or rain. While many types of mulch are organic, such as pine bark and hay, there are inorganic mulches available in the form of rocks or stone. Stone mulch looks nice and neat, and it doesn't have to be replaced. Watering plants with stone mulch is simple as long as you know how much water your plants need.
Check the soil under the stone mulch. Dig to a depth of 3 to 4 inches. If the soil is dry, the plants need to be watered.
Hold a hose or watering can over the ground around the plants about 2 or 3 inches from the ground.
Pour water on the stones around the base of the plants for 3 to 10 minutes, depending on the watering needs of the plants.
Repeat the process on all the plants surrounded by stone mulch until they are all watered.