Green Algae Control Lake Management

Identification of Emergent Plants

     The Emergent group of plants are most of your shoreline plants and basically any plant that grows distinctly above the water line. Cattails, Iris and Golden Canas are some well know plants that fit into the Emergent plant category. Because these plants are always exposed they are vulnerable to topical treatments and therefore most are easily treated.
    Though easily treated some of this vegetation may bring more benefits than disadvantages. Thick stands of Emergent plants provide a natural buffer for erosion control, habitat for fish, reptiles and other pond dwellers. Some even produce attractive blooms and flowers throughout parts of the year. Nutrient absorption and run-off filtration is another added benefit of desirable shoreline vegetation.
Yellow iris
Yellow Iris (pictured left) is a desirable emergent plant. In many cases such plants are brought in and planted to add structure, protection and aesthetics to man-made ponds. Spillways, areas of high water movement and critical embankments and shorelines prone to erosion are prime candidates for shoreline plantings.

Common Emergent Plants

     Cattails are probably the most well know and wide spread of all the emergent plants. Aside from cattails the rushes, Water primrose and Alligator weed are some of the more common shoreline plants to be concerned with. There are hundreds of species of rushes and sedges that are closely related but most of these are controlled with the same techniques so they are clumped into the rushes heading for the time being.
Rushes are erect cylindrical plants that often have tassel like seeds at or near the top. Spike rush and Bullrushes are the most common.
     Water Primrose commonly covers shorelines and will even send shoots or runners out into the water. The leaves are small green and almost always alternate with very visable veins. Flowers are Yellow and abunant when flowering.
     Aligator Weed is a Non-Native Invasive species. Commonly found along shorelines and even forming floating stands in larger water bodies. The leaves of Aligator Weed are small lush green and in an opposite pattern, more fleshy than that of Primrose and have a lack of noticable veins. The flowers are small white and resemble that of white clover flowers. Alligator weed is often confused with Primrose, there are certain similarities between the two but the main differences are the leaf pattern and flowers.

Control of emergent plants

     Treatment options are similar to that of Submerged plants. You again have Contact Herbicides, Systemic Herbicides and Mechanical and Biological Control. Systemic Herbicides are again going to be the most economical choice for long term control. Contact products offer quick results but are often short lived, especially with rhizomatic plants. Many emergent plants thrive and spread by Rhizomes, this is basically an extreme set of roots capable of producing new shoots. Fast acting herbicides often kill the extremeties of the plant before they have a change to transfer the product down to the root system. This basically kills the tops of the plants but leaves the roots and rhizomes to produce new vegetation in its place.
    Mechanical control is more practical with shoreline grasses as in many ponds these areas can simply be cut or mowed. Due to the locaiton of these plants there are very limited choices for Biological control.

Aquatic Plants Factsheets