Water plants can often be such rapid growers that they threaten to take over a pond. Check the prolific growers frequently to see if they need pruning. And use the exuberant growth to your advantage. You can acquire new, free pond plants by trading some of your excess to a fellow hobbyist. If you do need to thin out the pond, do so early summer so the plants have the chance for an extra summer growth spurt.
Floating Pond Plants
Floating pond plants sail around the surface of the pond in a kind of dreamy ballet, providing shade to inhibit algae growth, feeding off the nutrients in the water and even providing meals for the koi. One of the best known floating pond plants is the water hyacinth and it propagates so easily that in some regions, it is considered an invasive species. Duckweed is a tiny, bright green, round-leafed plant that looks like a scattering of dots on the water. It reproduces very rapidly, shades the pond and is both a good nutrient remover and a snack for turtles and fish. Water lettuce looks best in medium or large ponds. Its thick grey-green fuzzy leaves form a rosette like an open head of lettuce. The roots grow really quickly and supply an excellent water filtration system.
Rushes and Reeds
Pond reeds and rushes are naturals growing around the perimeter of the pond and can be planted in submerged containers or in muddy pond bottoms. The common bulrush grows to eight feet tall and spreads voraciously when left alone. If you don't have a lake, prune it. The common horsetail can become invasive. It grows to four feet and sometimes develops cones on the ends of the stalks. The great horsetail sends stems up from rapidly proliferating rhizomes. Vertical stems grow to twelve inches high with groups of leaves spaced along the stem. Unless you plan to weave them into hats, reeds and rushes are mostly decorative. They do provide some shade and cover for small aquatic animals.
Water lilies come in all colours and sizes and are the stars of backyard ponds. They do well in submerged planters and should not be planted too deeply. The albatross water lily is large, showy and grows like wildfire. It often blooms all summer. The marliac carnea has star-shaped pink flowers, smells like vanilla and grows easily in most pond conditions. The Hal Miller has 7-inch wide white flowers with yellow centres, dark green variegated leaves and grows and blooms nonstop. The Teri Dun has blue-violet flowers, dark green leaves and produces constant flowers all season. The Madame Ganna Walska produces big, pale pink flowers with buttery centres. It has blotchy red and green leaves and is one of the fastest growing water lilies. Lilies do absorb pond nutrients and give some shade but they exist to be beautiful and are there to be admired.