Bog plants are often called marginals in water gardening because they live around the edges of lakes and rivers or in bog-like conditions. Marginal plants can live in land and in shallow water. As the water line around lakes and rivers rises and lowers, the plants will often live in either condition.
Cattails are grasslike plants with long, slender stalks. The plants can grow up to 10 feet in height. In late summer and fall the plants form brown seed heads. The plants multiply through seeds and root division. If cattails are not managed, they may become invasive by completely encircling the pond. Most pond owners prefer to keep cattails trimmed back to about 10 percent of a pond's shoreline for visual interest.
Early French explorers called Louisiana iris les glis de marais, which translates to the glads of the marsh. Louisana irises bloom in the south from late March to late May. The flower grows actively in winter months and goes dormant in summer as the heat arrives. When the iris is grown on land it should be placed in moist soil and mulched heavily.
Papyrus is famous for being used to make some of the first paper in ancient Egypt. Papyrus is native to Egypt, where it grows along the banks and marshes of the Nile. Papyrus is a reedlike plant with a palm frond-shaped top. Full-size varieties can grow as tall as 10 feet in water or moist soil. The plant is hearty to USDA zone 9, and will die back to the ground and return yearly in zones 8 and 7.
Sweet flag resembles a young stand of cattails. The leaves give off a spicy-citrus scent; unlike cattails, this plant never grows taller than 4 feet tall. Mature leaves are differentiated from cattail leaves in that they have a central rib and a wavy edge. Sweet flag can be used to halt the spread of cattail stands.