How to Build a Sturdy Stone Wall

Dig a trench using the shovel. The trench should be the length of your rock wall, two feet wide, and should be six inches deep for every three feet of rock wall height. The bottom of the trench can be filled with gravel for increased drainage, but this is not necessary for a sturdy stone wall.

Line the bottom of the trench with the largest stones, making sure to choose flat stones for an excellent base. Round stones will cause problems at the base that will be reflected throughout the structure. Place the stones next to each other as close as possible with minimal gaps. Fill in cracks between the stones and between the stones and the wall of the trench with dirt and tamp it down with the shovel

Layer the rocks on top of each other, fitting them as close to each other as possible to ensure a tight fit and a solid wall. "Step back" the rocks by layering them so the rock surfaces slope forward at first, then backward with the next layer, and by thinning the width of the wall so that it is only one foot wide at the top and two feet wide at the base. This will greatly increase the stability of the wall. Set aside the longest and flattest rocks to serve as the capstones on the top of the wall.

Apply mortar, if desired, in difficult to fill areas that require additional support. It is also possible to use mortar throughout the wall for extra strength, though many people prefer the look of the gravity stacked wall with no mortar.

Place the capstones on the top of the wall. Ensure that these stones are level and fit together tightly, as they will be the most visible stones in the wall and under the closest scrutiny.