Planting a Water Garden

Containers, such as lined baskets, plastic tubs, dishpans, or clay pots, should be used to contain water plants. This will help prevent spreading and overcrowding. Fill containers with damp, heavy garden soil (avoid bagged potting soil or garden soil that contains chemicals or fertilizers harmful to aquatic life), pack the soil tightly in the container, cover with pea gravel to keep the soil from floating up, and lower the container to the correct depth in the pond.

Plants should be introduced to the pond during the growing season. Fish can be introduced two to three weeks after stocking with plants, but it is best to wait four or five weeks to allow time for the plants to get established.

Water lilies are one of the most popular pond aquatics because they are colorful, easy to care for, and highly fragrant. Tropical water lilies come in day-blooming and night-blooming varieties. They have larger, more-fragrant blossoms than hardy lilies, come in more colors, and bloom more often -- usually every day for the entire blooming season. In northern areas, they bloom later in the season. They can be placed in the water garden when the temperature reaches 65F at night and 75F during the day and grow best in 10 to 12 inches of water. Unless stored, they die when frost occurs. Most gardeners store them in a greenhouse pond over winter or treat them as annuals and replace them every year.

Hardy water lilies have longer blooming seasons in northern regions, but they have intermittent periods of dormancy, blooming for several weeks and then resting for several weeks throughout the blooming season. In general, they can be planted deeper than tropical water lilies, with some varieties surviving in 8 to 10 feet of water. They thrive in cold regions and don't need to be removed during the winter as long as the water doesn't freeze all the way to the rootstock. Both varieties need at least 5 and usually up to 10 to 12 hours of sun and regular fertilization.

The lotus, a relative of the water lily, is a much larger plant with magnificent blossoms. 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.

Bog plants include cattail; Japanese and water iris; bamboo; papyrus; and other tall, grasslike plants that thrive in the boggy, shallow areas that border the pond. Bog plants grow naturally in mud or in up to 6 inches of water, so they need to sit in a container on a "shelf" just below the water line. 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. Called "water weeds," they slow the growth of algae, absorb excess nutrients that would cloud the water, and provide fish with food. (If you have a small pool with no room for these plants, an aquarium pump will do the job). Varieties such as "elodea/anacharis" and "cabomba" are very inexpensive and can be bought by the bunch from suppliers. 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. They do not need any soil -- just float them in the water. 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.

by Ellen S. Bennett