Most of these plants do not cause problems for water users. Problem emergent plants include cattails, purple loosestrife and common reeds. Most of the structure of these plants float on the water surface. Most are rooted plants such as water lilies and spatterdock. Other varieties, such as duckweed, absorb nutrients by dangling roots in the water.
Experts say aquatic weed control can be approached using three methods, singly or in combination.
Most aquatic plants can reproduce by fragmentation, so cleanup will have to be repeated several times to eliminate new growth. Hartle explains that physical removal is effective only for small quantities of shoreline plants but reduces the rate of regrowth as well as the availability of nutrients. Mechanical plant harvesting is used only on large lakes. Landowners also can alter a pond's environment to control vegetation. Hartle says drawing down any pond larger than an acre requires a permit.