Hardy varieties thrive anywhere in the U.S., but some hybrid strains are not as tough in northern climates. They have a much shorter bloom season than lilies, but are popular because of their spectacular leaves and seed pods that often are used in flower arrangements. They too require at least five hours of sunlight and a water depth of 2 to 3 feet. Because lotus require very large containers, they are better suited to larger water gardens. Most varieties of iris require at least three hours of sunlight and grow best in full sun.
Cattails grow in partial shade or full sun.
Certain plants do not appear above the water, but are ecologically essential for pond balance because they continually replenish the oxygen supply in the water. The plants require sandy, gravel-like soil and are hardy enough to survive the winter. Plants, such as water hyacinth, have beautiful flowers and keep the water clear of algae and blanket weeds by minimizing the amount of sunlight on the surface. However, they are not recommended for areas where they might overwinter as they are extremely invasive and have caused tremendous environmental and economic damage in the southern United States.