Pond Plants & Algae

• Pond plants help keep algae under control. Nick M Do/Photodisc/Getty Images

  A water feature can be a dramatic focal point in your landscape, from small backyard water garden pools to large fish ponds. Pond plants and algae play a vital, interactive role in the water quality and appearance of your water feature, as well as providing habitats and food for fish and other wildlife.

Pond Buffer Plants

• Aquatic plants and algae -- microscopic plankton or tiny filament-like plants that grow in mats -- provide food and shelter for fish and other aquatic wildlife. Lakes without pond plants and algae are poor habitats for fish, reports the Cornell Cooperative Extension website. However, excessive growth of plants or algae removes oxygen from your pond water and renders it an unsuitable habitat. The most effective way to prevent weed species overgrowth or algae "blooms" is to reduce the amount of nutrients reaching the pond by planting emergent or wetland plants around the edges of the pond, according to the PennState University Cooperative Extension site. Cattails (Typha latifolia) that root in the saturated soil but maintain their stems and leaves primarily above water level help to slow the flow of water running over the surface of the ground, giving it time for excess nutrients to settle out. Blueflag Iris (Iris versicolor) and Sweetflag (Acorus spp.) also thrive at a pond's edge.

Floating Plants

• Floating plants trail their stems and roots in the water, with their leaves and flowers held at or above the water surface. Floating plants like duckweed (Lemna minor) and water lilies (Nymphaea spp.) absorb their nutrients from the water, competing with algae and helping to keep its growth in check, according to the PennState University Extension. Water lilies have the added advantage of shading the water, which also contributes to limiting algae growth, advises the Texas A&M University Extension website. Plant enough water lilies to cover 50 to 75 percent of the water's surface at maturity for optimal algae control, Texas Extension recommends. This gives you a dramatic display of water lily flowers in the early summer.

Submerged Plants

• Submerged plants differ from algae in that they have true stems and leaves. However, like algae they grow completely or nearly completely under the surface of the water, explains the PennState University Extension. A mix of desired pond plants, including emergent or buffer plants, floating plants, and submerged plants, helps exclude excessive algae in the same way that dense plantings of desired species in the perennial bed help to exclude weeds, advises the University of Illinois Extension. Submerged plants play a critical role in oxygenating the water, according to the Texas A&M Extension. Cabomba (Cabomba caroliniana), anacharis (Elodea canadensis) and water milfoil (Myriophyllum spp.) are all common submerged pond plants. However, many species of submerged plants become aggressively overgrown in warmer climates, including the European milfoil (Myriophyllum spicatum), so check with your local Cooperate Extension before selecting submerged plant species for your pond.