Most of our landscapes have an assortment of materials -- plants, mulch, gravel, grass -- so how do you keep everything neat and orderly? We want grass to stay in the lawn and out of the beds and mulch to stay in the beds and off the pathway. There are many ways to separate, or edge, your different garden and yard areas, from inexpensive and quick to costly and involved. Here's a rundown of some of the more popular edging materials, from less expensive to costlier. Which one is right for your garden?