Lawn borders are not necessary, but they provide a degree of separation between flower beds, fences, walkways and driveways and can save you the time of trimming grass along those edges. When selecting from the numerous types of edging that define lawn borders, consider what is most practical and pleasing for you and your family.
Trench edging is the easiest type of lawn edging because it simply requires you to dig a trench 4 to 6 inches wide that cuts off the lawn from its adjoining garden features. The trench edge is cut with a spade to a depth of about 6 inches, which must be cut once or twice annually to maintain the sharp, clean edge. A flower bed border benefits from trench edging because it prevents grass roots from crossing over into the cultivated bed. The space directly under a fence is another good use of trench edging because it keeps the grass away from the fence so you don't constantly hit the fence while using a weed trimmer. Add gravel to trenches under a fence to improve drainage so water doesn't rot the bottom of fence pickets.
Stone borders are set inside a trench and buried to about half the depth, otherwise grass can creep through the cracks between stones. This also requires 2 to 4 inches of crushed gravel to create a sturdy base layer to prevent the stones from shifting. Stone edging isn't practical under fences, but works well to add extra definition along flower beds, patios, walkways and driveways. You can use fieldstone, sett stone, or natural stone pavers, depending on the desired look. Setts and pavers are carved to uniform shapes for a formal appearance; brick pavers can also be used. Uniform stones and bricks placed even with the soil grade eliminates the need for trimming because you can run a lawn mower over them.
Concrete offers a cheaper alternative to stone and brick borders, while still providing a hard transition to define the edges of your lawn. You can purchase pre-formed concrete curbing to lay along the edges or dig a trench about 4 inches wide and fill it with concrete yourself. When set in the ground, you can mow directly over the concrete without damaging the equipment. If you don't care for the color of concrete, you can dye it any shade you like.
Polyvinyl and Metal
Polyvinyl and metal landscape edging offer the same benefits as other edging types, but are the least obtrusive options. Although made from different materials, they are both thin strips about 4 to 6 inches tall that you bury in a narrow channel along the lawn's edge. There is usually a small, round section that sticks out no more than 1 inch above the soil. While you can use this edging in any lawn application, it works particularly well along hard-paved surfaces such as walkways because you can grow the grass tight up against the walkway without it spilling over onto the surface.