- The healthiest water gardens with the cleanest water contain a mix of floaters, submerged (oxygenating) plants, marginal and bog plants and deep water plants.
Floaters
- Floaters, just like their name, float in the water, their leaves and blossoms on the surface, their roots dangling loose beneath. This group includes water lettuce, water hyacinth and duckweed. These provide shade and food for fish. In fact, foliage of floaters and other deep water plants should cover about half the pond surface to shade the water. But, if they cover more than 2/3 of the pond, they trap carbon dioxide and other gases fish need to survive.
- Floaters: Water Hyacinth, Duckweed & Water Lettuce
Submerged, Oxygenating Plants
- These plants slow algae growth, replace lost oxygen and provide shelter and a good breeding ground for the fish. They grow in pots at the bottom of the pond, but their foliage grows primarily underwater.
- Many oxygenators are very aggressive and can easily take over a pond if not controlled. These plants can be thinned and the cuttings shared with friends. To thin them, just take a garden rake forcefully through the underwater vegetation.
- Submerged Plants: Water Milfol, Hornwort & Parrot’s Feather
Marginal Plants
- The function of a marginal is to add color and height and help the water garden blend visually into the rest of the landscape. They are, for the most part, simply aesthetic. Though, roots which escape the pot may help remove unwanted nutrients from the water.
- Marginals thrive in shallow water (2-3 inches) and moist soil found at the edge of a pond. They sit on the ledge of your water pond while gravel on top of the soil keeps it in place. Tuck marginal plants into pots to prevent their aggressive nature from overtaking your pond. These pots also allow you to mix and match plants that require different depths.
- Tall marginal aquatics should be reduced in height to 9-10″ to prevent them from being blown over before the roots have obtained hold.. Most marginal requires slight thinning each year, especially some of the more vigorous varieties. Most spread readily and small pieces can easily be removed and replanted.