Garden edging provides a transition between a landscaping bed and a lawn. Edgings also help to prevent grass from creeping into the landscaping bed and keep mulch inside the bed. Though the simplest edging to install is a dirt trench around a landscaping bed, this kind of edging requires constant maintenance. A more permanent edging is one that you pour yourself from concrete. Concrete edging requires more work to install, but lasts for a long time with very little maintenance.
Dig a trench for your garden edging that is at least 6 inches wide and extends beneath the frost line for your area.
Cut pieces of 3/4-inch plywood into 7-inch-wide strips. Place these strips end-to-end along the walls of your trenches to create a concrete form.
Spread 2 inches of coarse sand over the bottom of the trench. Smooth the sand with a rake and compress it with a tamping tool. Measure that the surface is level by placing a leftover piece of the plywood flat on the surface of the sand and then placing a carpenter's level on top of the plywood. If the sand is level, the bubble in the centre of the tool will move to the centre of the gauge. If the sand is not level, rake it and tamp again.
Mix concrete and water in a bucket with a trowel until the concrete is the consistency of cake batter. Pour the concrete over the sand between the forms.
Cure the concrete by sprinkling it with water and then covering with plastic for 5 to 7 days. Remove the plastic and the concrete forms and allow the concrete to dry for an additional 2 days before planting your flower bed.
Always wash your tools before the cement on them has a chance to harden.