Marginal water plants grow along the edges of ponds, rivers and lakes or in very moist soil. While they like to get their feet wet, they do not grow in deeper water, like other water-loving plants. Marginal water plants can usually only handle growing in 6 inches of water at the deepest. Planting marginal water plants will add interest and height to the edges or your water garden. Sweet flag, cattails and calla are all good marginal water plants to plant.
Choose the marginal water plants you would like to grow around your pond. Make sure they are hardy to your USDA climate zone.
Fill pots with heavy clay or aquatic potting soil. Planting marginal water plants in pots helps keep them in check and allows you to care for them more easily. Marginal water plants need heavy soil in which to grow so they do not float away in the pond.
Dig holes for the marginal water plants, deep enough for the plant's rhizomes and two times as wide.
Place the marginal water plants rhizomes into the holes and cover them with soil loosely. Add a 1-inch layer of gravel on top of the soil to hold it down under the water.
Place the marginal water plants in position around the pond. Submerge them in the water to the depth preferred by the plant.