There are a number of materials used to disguise the liner of a pond. Concrete pavers, stone and natural edging are the most common. Each type has advantages and disadvantages.
Natural edging is accomplished by mounding earth over the exposed pond liner and planting fast-growing groundcover and small shrubs in this berm. This method works well for large ponds where the cost of pavers or stone would be prohibitive. Choose fast-growing perennials, such as creeping thyme, water iris and ornamental grass, for the initial planting. They stabilise the soil and prevent erosion. In the following seasons, other perennial species may be added.
Stones should be of varying sizes with soil pockets for planting in between the empty spaces. Interplanting perennials and small shrubs helps the rock edging blend. In nature, rock formations are not uniform, so use that randomness as a guide when placing the stones.
Pavers are a relatively cheap way of lining the edge of a small-to-medium size pond, although they really look their best around a formal style pond. Informal ponds can look contrived with pavers, especially if the surrounding landscape is loose in style. For a formal style pond and landscape, the pavers lining the edge can be matched to sidewalks and paths. Pavers around a pond should be mortared in place as a safety issue.