There are generally two varieties in this area, Water Lettuce and Water
Hyacinth. They both simply float on the water surface never rooted in soil. The dangling roots are continually absorbing the nutrients floating in the ecosystem keeping the water quality in check. Placing the Hyacinth in the biofalls filtration maximizes the benefit of the plants with all the passing water for it to filter. In mid July always check for water flow restriction due to the rapid growth of this plant and the strain it can put on the system. As this plant rapidly expands, it may be pertinent to discard some. Be sure that they are discard in the trash or a compost pile and be absolutely certain that they can not make it to a natural water source!!
If Koi are the gem fish of the water garden, then unquestionably the Lotus is the gem of aquatic plants. Lotus are planted in the deeper water and sprout high above the water level. They bloom a gorgeous flower that can later be used for indoor dry flower arrangements. A distinguishing feature of these plants, is that it repels rain water rather than absorbing it.
These plants run the gamut of types of plantings and depths, but generally should not be planted any lower than the top shelves of the water garden. Most are hardy plants that will survive through the winter. They should be cut back to just below the ice line in late fall. Some common types are:
Sweet Flag, Rushes, Iris, Water Forget-Me-Not, and Cattails.
The two major classifications water lilies are hardy and tropical. Tropicals can be night bloomers or day time bloomers. Tropicals may be easily
For the ecosystem, this plant offers shade to the water, helping to keep the summer time temperatures in check, benefiting both the fish health and water quality.
Why do we need aquatic plants?
Aquatic plants offer two major benefits to any water feature. First and foremost they are attractive looking plants that complete the landscape.
They soften and naturalize the areas in and around the water garden. Secondly, the plants offer much needed filtration for the ecosystem. The roots of the plants compete for nutrients with algae. This means, if you have many plants essentially stealing the nutrients from algae, then the algae will have a much more difficult time to bloom, but your plants will do great! Most problems with algae can be solved by adding plants to the pond. This is especially true in a pond that gets many hours of sun each day, you will need many more plants than a pond that is not in direct sun.
Note: For those that were unsure, "hardy" is the aquatic plant term for plants that come back every season. This is the equivalent to "perennial" for terrestrial plants. "Tropical" is the aquatic term for plants that die as a result of the winter and colder weather. This is the relative term to "annual" for terrestrial plants.
These plants (Hornwort or Anacharis) are great in providing a spawning area for the fish as well as a hiding area from predators. As the season progresses, they grow and help moderate the temperature of the water. They can double in size in a season. Simply drop them in the pond and they will take care of themselves!