Pond plants add color and beauty to your pond, but their benefits are not just aesthetic. Aquatic plants provide oxygen for fish in your pond. They also filter and clean the water. Most importantly for many pond owners, plants in a garden pond can prevent the growth of unattractive algae. Pond plants can be divided into four groups: oxygenators, marginal plants, floaters and deep water plants.
Oxygenators are plants that grow completely under the water. They provide cover for spawning fish and use up nutrients in the water so algae cannot grow. They also add oxygen to the water, and often bubbles can be seen coming from the leaves of these plants. Red Ludwigia, which features variegated red and green leaves, is one example of a submerged plant. Hornwort, a graceful plant that has long, thin leaves, is a submerged plant that fish especially love. Vallisneria has long leaves that look like green, shiny ribbons.
Marginal plants are those that are planted on the edges of garden ponds. These plants soften the transition between the pond and the surrounding landscape, and they add a pleasing border. Most can be submerged in a few inches of water. Cattails are one of the popular marginal plants and are especially popular with children. Rushes, with their tall, thin stalks of grass (some also have flowers) make a pleasing sound when the wind moves them. Some irises, such as the Louisiana iris, also make appropriate marginal plants.
No pond is complete without a few floating plants. These plants float on the pond's surface, drifting with the water. They are not anchored to the soil. Some are quite excellent at filtering the water, especially water hyacinth. Frog bit resembles the leaves of water lilies and spreads very rapidly. Parrot's feather has lime green, feathery foliage and also spreads rapidly.
Deep Water Plants
The centerpiece of any pond is its deep water plants. Deep water plants are anchored at the bottom of the pond, but the leaves and flowers either float on the surface or rise a few inches above the surface of the water. The best-known of the deep water plants is the water lily, which comes in many shapes, sizes and colors. Hardy water lilies are perennials that bloom all summer long. Tropical water lilies also have prolific blooming habits but must be removed before the first frost. Hardy lotus plants are even showier than water lilies but are not nearly as common. These beautiful flowers have blooms that can be as large as 12 inches across and can protrude up to five feet above the water.