The term edging has a double use. As a verb, edging refers to cutting a sharp line of separation, usually between a planting and the adjacent lawn. Reference may be made to edging a bed or edging the lawn along a walk. The term can also be used to describe a product, usually a steel or plastic strip that can be installed as a physical separator between plant­ing beds and lawns or between lawns and paved areas.

To edge a bed requires an edging tool or a flatback spade. The edger or spade is dug into the ground to a depth of six to eight inches and a wedge of sod removed (Figure 11-4). The process continues along the edge of the bed or the paved area. Cutting through the sod sharply and vertically discourages the roots of the turf from growing into the bed. If the landscape is large, edging can be accelerated by using a power edger.

The installation of edging material against the cut edge further dis­courages the horizontal spread of grass roots into the bed. It also retains a sharp turf line along walks and drives. The best edging materials are firm, not easily bent and crushed. The corrugated foil edging promoted

figure 11-5. Plastic edging should be anchored at the time of installation to prevent winter heaving. Here a metal rod is driven through the edging into the soil and clipped over the lip of the edging. (Delmar/ Cengage Learning)

to the home garden market is not satisfactory for professional use and should be avoided. Heavy-gauged steel and polyvinyl-chloride edging is available from numerous manufacturers. Satisfactory edges can also be created with wood, bricks, and other modular manufactured materials.

In regions where winter heaving of the soil is common, it is best to select an edging material that can be anchored (Figure 11-5). Most anchoring techniques are only moderately effective, however, and reset­ting heaved edging is a common spring activity in northern landscapes. It is worth the effort, considering the advantages that the material offers in retention of the bed line and separation of the mulch from the lawn mower.