These plants are more decorative than functional. However, when planted in containers on the marginal shelf—the ledge around the inside of preformed ponds, about 12 in (30 cm) below the surface—they can provide retreats for young fish. Marginals can also be grown as edging plants, giving the pond a more informal look and creating a barrier that makes it more difficult for predators to reach the fish. Some marginals trail down into the water, which helps to hide the perimeter from view. All the plants featured here are suitable for temperate climates, but some will benefit from protection in winter.