Edging provides a clean, well-defined boundary in a garden. When installed to a proper depth, it also deters runners and weeds from spreading into, or out of, the bed. When forming a cement edge, be sure to allow at least 48 hours for the cement to dry and set before working in the flowerbed.
Mark the entire cement edge area with marking chalk.
Dig a trench that is two feet deep and at least 1 foot wide.
Place the plywood sheets on both sides of the trench to create a straight wall for the cement. If the edge is curved or wavy, then use plywood strips, instead of the full reinforced plywood sheet. Secure them into place with stakes positioned along the outside.
Carefully read the instructions on the cement bag and mix it accordingly in a wheelbarrow.
Shovel the cement into the trench and fill it up to the top of the plywood. This will create an edge that is 2 inches above the soil line.
Smooth the top of the cement with a trowel and allow the edge to dry for 48 hours before removing the wood.
Remove the plywood and fill in the spaces with dirt.