Lawn edging keeps the lawn from invading areas where it should not be, such as your driveway and under your foundation shrubs. Several kinds of lawn edging are available, from plastic strips to landscaping timbers to cast concrete blocks, but the most attractive is natural stone. Granite, slate and fieldstone are popular choices for landscape edging. If your budget won't stretch to natural stone, consider the many cast concrete products shaped and coloured to look like natural stone. Whatever type of edging you choose, careful preparation and installation will give you a result that will add value to your property for years.
Measure the perimeter of your lawn using a tape measure. If absolutely straight lines are important to you, pound wooden stakes into the lawn at the corners. Stretch a piece of twine between the stakes to guide your installation. Mark the perimeter along which you will set the stones with landscaper's spray paint.
Convert your measurement of the perimeter of the lawn into inches. Divide that measurement by the length of the block of stone you have chosen to figure out how many stones you will need. This method will not work for fieldstone, which does not come in regular blocks. Take your perimeter measurement to the vendor and ask her to figure out how much material you need.
Figure out how deep the trench you are going to dig should be. Measure the height of the stone block. Decide how much of the block you want to be above grade. Subtract that measurement from the height of the stone block. Take the remainder and add 4 inches for the gravel and sand bed into which you will set the stones.
Dig a trench around the perimeter of your lawn, making it the number of inches deep you calculated and 1 inch wider than the block of stone. Use a square-bladed spade and make the inside edge of the trench absolutely vertical. Tamp the bottom and inside edge of the trench using a piece of 2-by-4 inch lumber.
Cut strips of landscaping fabric to cover the sides and bottom of the trench. Install the fabric in the trench, overlapping the strips by 4 inches.
Fill the bottom of the trench with 2 inches of crushed gravel topped by 2 inches of coarse sand.
Set the stone blocks into the trench, butting them end to end and pushing them hard up against the vertical edge of the trench. Use the 2-by-4 inch board to push the stone blocks into place so they are even with each other. Fill in any gaps between the stones with crushed gravel and sand. Continue laying the edging around your lawn. Back fill the trench on the outside of the edging with crushed gravel.