How to Build a Rock Garden on a Slope

Till the area with the rototiller where the garden is to be located to break up solid ground and make excavation easier. Allow the tiller to work to the deepest depth it can manage.

Excavate the area where the boulders and rocks are to be installed using the shovel. To create an aged look, each of the rocks should be half buried. Determine the place for each rock and stone, and dig that spot appropriately. It is best to position the rocks in as natural possible. Nature does not adhere to design theories, so it isn't necessary for you to, either. Place the rocks wherever you think they look best.

Insert the rocks and boulders into their respective excavations, then fill the gaps between the rock and the dirt with the excavated dirt. It is easiest to have the boulders and rocks delivered and placed on the uphill side of the slope so that they can be rolled downhill, rather than pushed uphill.

Smooth the sloped ground surrounding the rocks with a stiff-tine rake, then plant the area with an assortment of perennial flowers and ground cover plants to retain the soil between the rocks. Because it is on a slope, it is very important to have vigorously-growing, and deeply rooted plants to help retain the soil when it rains. This also helps impart a more natural look to the rock garden, which is the ultimate goal.