Types of Water Plants Available at Cooper’s

Why do we want aquatic plants?

Aquatic plants offer two makor benefits to any water feature. First and foremost they are attractive looking plants that complete the landscape. They soften or naturalize the areas in and around the water garden. Secondly the plants offer much needed filtration for the ecosystem. The roots of these water plants compete for nutrients with algae. This means, if you have many plants essentially stealing the nutrients from algae, then the algae will not bloom. Your plants will bloom instead. Most problems with algae can be solved by adding plants to the pond. This is especially true in a high sun pond, you will need many more plants than in a pond that is not in direct sun.

Types of Aquatic Plants:

The two major classifications of aquatic plants are Hardy & Tropical. The tropical versions are referred to as either Night Bloomers or Day Time Bloomers due to the time of day they bloom. Distinguishing the lilies is done by identifying the type of lead or pad that floats on the water surface. Hardy lily pads are smooth while the tropicals are jagged. For the ecosystem, this plant offers shade to the water, keeping the summer time temperatures in check for both fish health and a balanced water quality.


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 deepr water and sprout high above the water. They bloom a gorgeous flower that can later be used for indoor dry flower arrangements. A distinguishing feature of this plants is that it repels rain water, rather than absorbing it.


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. They are also very effective in streams, simply place a piece of gravel on the roots to hold it in place if a corner is not available.


These plants are great in providing a spawning area for the fish as well as a hiding area for predators. As the season progresses, they grow and help moderate the temperature of the water. They can double plus in size in a season. Simply drop them (is. Hornwort or Anacharis) in the pond and they will take care of themselves.

Marginal Plants:

These plants run the gamut of types and planting depths, but note they generally should not be planted any lower than the top shelves of the water garden (remember, marginal means a marginal amount of water). Most are hardy and should be cut back to just below the ice line in late fall. Some of the common types found in this area are: Sweet Flag, Rushes, Papyrus, Irises, Forget-Me-Not, and Cattails.

Water Plants you should have based on pond size

Kit Size   Sq Ft    Water Lilies    Marginal Plants    Oxygenators    Floating Plants
4 x 6         24                  1                           5                        8                          2
6 x 8         48                  1                           7                      16                          3
6 x 11       66                  1                           7                      22                          5
8 x 11       88                  1                           9                      29                          6
11 x 11     121                2                           9                      40                          8
11 x 16     180         2 or 3                         11                      59                         13
16 x 16     256                3                         14                      84                         18
16 x 21     336                4                         17                    111                         24
21 x 21     441         4 or 5                         21                    146                         31
21 x 26     550         5 or 6                         27                    182                         39
26 x 26     675         6 or 7                         33                    223                         47
Larger Ponds
per Sq Ft                  0.011                      0.05                  0.33                      0.07


Next: Learn about Fish for Water Gardens

Natural Ponds: Common Problems and Treatments

Common Problems

  • Algae growth and other undesirable aquatic plants
  • Excessive bio matter (leaves, branches, dead vegetation)
  • Lack of water movement


Generally there are cattail family plants (Iris, lilies, rush & grasses) which are very healthful, but also aggressive growers and require pruning to keep them balanced.

Duckweed a type of floating plant – will cover a pond quickly generally due to lack of water movement, and will sit all growing season long.
Algae, there are generally two types (peas soup or string) and they blooms due to excessive nutrients and strong sun light.
Most treatments for aquatics require special State approval and not treatable as in other states do to CT regulations.


Bio-Mass is all the fallen leaves, branches, trees and dead aquatic plant growth (organics) from previous years. The slow decay creates excessive nutrients which is a “food” for the algae and other “plants” you don’t want. The massive build up of this material year after year reduces the depth of a pond, which further decreases the health of it.


Movement of the ponds water is a natural purging and cleansing of the system in both surface from a stream inlet and opposite end overflow and in good depth, the bottom will move/turn over. This is very healthful for the system.

Suggestions and Solutions

1. Move the water, move the water!

In the majority of the cases my shrst recommendation would be bottom aeration. This is a green solution, with a compressor on shore and a diffuser at the bottom bubbling the water, increasing in effectiveness the deeper the pond.
When shallow depths are the case, bottom aeration is not the recommendation. Instead use a water pump. This can be a fountain with a spray into the sky and splash back down to the pond, generally more decorative then functional, but aeration is added this way and lights can be added if desired.
The next alternative for achieving maximum water movement would be horizontal circulators, moving large volumes of water across the surface of the pond. This is a great option as it usually requires only 12-18” of water and can cover a large area of the pond to aid with the bio-mass decomposing.

2. Break down the bio mass

This is best accomplished with water movement and beneficial bacteria. The bacteria will aid in breaking down the organic masses that have built up over years of neglect and have resulted in the shallowness of the pond which once had good depths. Adding the bacterial sure beats having a pond dredged based on cost, but it is NOT an immediate fix. Adding the bacteria should be done monthly during the growing season, usually April through October in this area.

3. Add plants

Attractive aquatic plants provide shade. Shade mediates water temperature as a results, limits the amount of excess nutrients. Attractive plantings in the pond offer competitive higher level plant life to bloom in the pond. When planted on a floating island the root structures can grow rapidly utilizing the excess nutrients discussed above. In addition the islands offer shade to mediate the temperature holding un-wanted plant growth to a minimum. Plus the island can be taken ashore in the fall and the excessive bio-mass can be pruned easily and REMOVED from the pond before decaying there.

4. Regular Maintenance

Pruning and basic cleaning of the pond is a basic labor skill that can best be hired through your landscaper. Although specialized pond service contracts are available at Cooper’s.


Cooper’s is in the business of selling product and providing consultation to the trade and homeowners.  Many of the above products are available at our store 203-790-6700 or learn more eMail Brad@CooperPonds.com.