Watermilfoils: tough aquatic weeds

The group of water weeds known as watermilfoils (Myriophyllum) or milfoils are widely distributed in freshwater lakes and ponds around the world. Their rapid growth and tolerance of adverse conditions (including heat, cold and high salinity) can lead to unsightly heavy mats of plant material, stagnant water (ideal for mosquito breeding) and clogging of intake pipes.

Control strategies for milfoils are listed below:

- Cultural control: There is some evidence that lowering the water level about 6 feet can reduce…