Laying an edging around any garden bed is a practical way to create a visual border to the garden and keep grass from your lawn from creeping into the bed. The simplest way to lay garden edging on your own is with plastic strips which interlock with each other or by setting in bricks one after the other. No matter which option you choose, the difficulty of the process and the time it takes will be determined by how much garden bed you need to cover.
Dig a border around your garden with a shovel or pickax to make a trench about 4 inches deep and 4 inches wide. Measure the full length of your trench and purchase enough plastic edging and brick to run that length.
Insert plastic edging into the trench if you are using it, interlocking pieces as you go, to run the full length of the trench. If necessary, use a handsaw to trim the edging when you reach the end.
Lay a length of black plastic a foot wide through the bottom of the trench followed by an inch to half an inch of builder's sand if you are using bricks. Set your bricks into the trench starting at one end and working toward the other. The black plastic should cover the bricks on both sides and underneath the bricks.
Use a rubber mallet to anchor the plastic edging into the trench so it is vertical and not tipping toward the yard or the garden bed. If using bricks, tap the bricks to nestle them into the sand and against one another. Both the plastic and brick edging should be only half an inch above the ground so you can easily mow over it.
Push the soil from the trench around the plastic edging to fill in the trench, and pack it tight. For the brick, push the loosened soil against the black plastic to secure the bricks in place. Cut the black plastic back to ground level with the scissors if it sticks up past the brick on the lawn side of your garden edge.
Spread a ½-inch of sand over the bricks and sweep it between the bricks with a handheld sweeper, filling the gaps between the bricks. Spray down the bricks with a mist of water to help set the sand. Add more sand and spray again as needed until the gaps are filled.