Curleyleaf Pondweed (CLP) is an invasive exotic annual plant which came from Europe. Unlike our native plants, there are no natural controls. CLP tends to crowd out native plants and will mat on the surface restricting recreation.
CLP reproduces from bulbs called turions. These turions become next year’s crop. Our strategy is to cut the plant before it sheds these turions. The best time is the middle of June when the plant is mature. Cutting will not kill the plant, it will start growing again but if the cutting is done when it’s mature, it will not have time to grow new turions before it dies about the first week of July.
A hand-held “weed chopper” costs about $6-7 and is good for shallow water. For deeper water, use a rake. For very deep water consider tying the rake to a rope. A double-tine garden rake is the ultimate as it always lands on the right side. Be sure the cut plants do not float away (landing nets work) and dispose of them on land.
When the plants get too dense, the only option is chemical. The product used is Aquathol. If applied in early spring, Aquathol will not harm the native plants since curly-leaf is the first plant to grow in the spring. It dissipates quickly leaving no residue and does not bio-accumulate in fish or hydro-soil. It is approved by the Federal EPA and the DNR. After application, there are no restrictions on swimming and a 7 day advisory for watering lawns and plants.