This simple stone wall does more than divide a garden or mark boundaries -- it lends romance to a backyard.
Choose stones that blend well together in color and texture. You should get a good variety of sizes. You can use uncut rubble (pictured here), semidressed stone (roughly cut into rectangular shapes), or ashlar (stone that is carefully squared and trimmed). A mortar wall must be built on a firm foundation, or its joints will crack. Dig a trench about 6 inches wider than your wall. It must be deeper than the frost line, or at least 12 inches deep for a 3-foot-high wall. Tamp the gravel in the bottom of the trench, and pour at least 8 inches of concrete. Top off the concrete 2 inches below grade. Have the stone delivered as close to your building site as possible. Allow plenty of time for the project. Stone work is a matter of continual trial and error, testing to see which combination of stones works best.
2. Set the first course in a 1-inch bed of mortar applied to the 8-inch concrete footing. Start with a tie stone, a stone that spans the width of the wall. Use larger stones for the faces, and fill in the middle with smaller stones and mortar.
3. Add stones. Dry-fit each successive course of stones, then make a mortar bed and carefully lay the stones. Place a tie stone every 4 feet or so, in alternating positions for each succeeding course. Use the batter board on the straight runs of the wall; freehand the curved corners. If a stone is squeezing mortar out of the joint, use wooden wedges to temporarily hold it up. Aim for fairly uniform joint spacing.
4. Rake the joints as you go, using a scrap of wood. Raking the mortar to a depth of 1 inch or even a bit more will add interest to the wall, producing pleasing variations of light and shadow.
5. Finish. Clean spilled or smeared mortar off the face of the stones as soon as possible using a wet sponge. Immediately after raking, remove mortar crumbs with a whisk broom. After the mortar has dried, wash with plain or soapy water. Avoid using a wire brush or an acid solution, which can harm some types of stone.