Rake the dirt around the border where you will place your rocks to remove any debris, weeds and sticks from the area.
Dig a trench using your shovel. Dig a trench deep and wide enough along the garden edge where you expect to lay your rock border. The trench should accommodate the size of your rocks.
Shake 2 to 3 inches of sand or mulch evenly inside the trench using a shovel. The sand or mulch retains moisture, limits weed growth and reduces erosion.
Select large rocks or stones for your border. Sit the rocks inside of the trench all around the border closely together.
Tap the rocks inside of the trench using a rubber mallet to keep the rocks stable.
Sprinkle the rocks with your garden hose to clean them off.