Rocks and stones are natural landscaping materials that add interest, create temperature microclimates around them, and serve a multitude of landscaping functions. The most difficult part of using them in the garden is deciding where you'd like them, followed closely by the muscle needed to move them from place to place.
A series of similar-sized stones set along the edge between lawn and flowerbed, or ringing a tree gives the area a soft and natural-looking division. If the stones are about 5 inches or more, and are buried a third of the way in the ground, the border also helps keep grass from getting into areas it's not welcome. Set the stones edge to edge and pack soil tightly against the back and front faces to keep them in place. This edging will also help keep mulch from running out of beds.
Accents and Seats
Use large rocks and boulders as centerpieces and accents in the garden. Bury them at least a third of their height deep to make them fall into the landscape naturally, and use them alone or in groups of three or five for greater visual appeal. Large rocks with a flat top make convenient, simple garden seats. Set them in partial shade to keep the tops from becoming too hot in the summer.
Walkways and Steps
Choose wide, flat rocks as stepping stones. Bury them halfway in the ground so they're more stable. Leave gaps of 3 to 5 inches between them to grow groundcovers such as creeping thyme for a scented walkway, recommends the University of Wyoming Extension. Very gradual steps are relatively easy to install, especially if there's a distance of natural slope between steps. Again, bury these at least halfway, if not more, in the ground for added stability.
Don't try to move large rocks or boulders alone. Having one other person around, even to keep an eye on you in case something slips, is crucial. Move stones by rolling instead of lifting, and roll them into and out of wheelbarrows set on their sides to transport them. Water in the soil around walkways and steps to add stability. If necessary, work the stones into a 1-inch-deep layer of sand to make sure the bottom surface has complete contact with the ground and doesn't shift.
If you live in a rocky area, set aside the stones you pull from your garden when you're preparing the soil. Set them aside for later projects to avoid the expense of purchasing stones. Rocks from the surrounding environment tend to look more natural in the landscape. Tuck small plants that need cooler temperatures on the north side of a big boulder, and plants that like it sunny and hot on the south side.