Aquatic plants are more than just exotic additions to a water feature. These hard-working beauties play several key roles in a pond’s ecosystem, from controlling algae growth to providing shade, food, and protection for fish. Aquatic plants are grouped into four varieties: water lilies, marginals, floating plants, and submerged plants.
Plan ahead: Some varieties of aquatic plants need to spend the winter indoors. Planting pockets into your pond allows you to place a potted plant in the pocket. Rocks can be used to hide the pot. These pockets allow for the potted plants to be easily removed when the weather turns colder.
Hardy species of water lilies are reliably perennial from the northern reaches of the U.S. Department of Agriculture’s (USDA) Zone 3 to the subtropical areas of Zone 11. Water lilies are available in an array of colors including, white, pink, red, or yellow flowers. Floating directly on the top of the water, the flowers of water lilies open during the day and close at night. Make sure to remove any spent foliage before winter. New leaves will emerge in the spring.
Tropical water lilies are hardy in USDA Zones 10 and 11. They can also be planted in colder zones where the water temperature is consistently above 70 degrees F. The flowers of these plants are fragrant. While most water lilies bloom only during the day, some of the tropical water lily varieties also bloom at night.
Fertilizing water lilies encourages an increase in size and quantity of flowers. One option for fertilization is time released granular fertilizer, which mixes into the soil at the bottom of the pot or planting pocket at the time of planting. Another option is lily fertilizer tablets.
Marginal Aquatic Plants
Marginal aquatic plants often line the edges of a water garden. Their main purpose is to help filter the water as well as removing elements which feed algae.
In a rock and gravel pond, marginals are normally placed directly in the gravel, allowing the plants to naturally thrive as well as providing optimal filtration. Tropical varieties need to overwinter indoors and should be left in pots to facilitate removal.
Floating Aquatic Plants
These plants float at the surface with their roots hanging into the water. Most floating aquatics are tropical with some are hardy perennial varieties flourishing in climates with hard winter freezes. Hyacinth (NOT the garden variety bulb!) and water lettuce are good choices to disguise the top of the BioFalls Filter.
Submerged Aquatic Plants
Submerged aquatics are commonly called oxygenators, but their name is a misnomer. These plants produce oxygen during the day, but at night and on cloudy days, they use oxygen to produce carbon dioxide. Submerged aquatics are efficient at using nutrients in the water and are good hiding places for fish.