Control Options
Mechanical/Physical
- Curly-leaf pondweed can be removed by raking or seining it from the pond but will reestablish from any remaining roots. Aquashade is a non-toxic dye or colorant. It prevents or reduces aquatic plant growth by limiting sunlight penetration, similar to fertilization. However, Aquashade does not enhance the natural food chain and may suppress the natural food chain of the pond.Biological
- Grass carp will seldom control aquatic vegetation the first year they are stocked. They will consume curly-leaf pondweed. Grass carp stocking rates to control curly-leaf pondweed are usually in the range of 7 to 15 per surface acre. In Texas, only triploid grass carp are legal and a permit from the Texas Parks and Wildlife Department is required before they can be purchased from a certified dealer.Chemical
- active ingredients that have been successful in treating curly-leaf pondweed include diquat (G), copper with diquat (G), endothall (E), and fluridone (E). E = excellent, G = goodReward is a liquid diquat formulation that has been effective on curly-leaf pondweed and is more effective if mixed with a copper compound. It is a contact herbicide. Contact herbicides act quickly and kill all plants cells that they contact.
Cutrine Plus, K-Tea, Captain, Algae Pro, Clearigate are all chelated or compound copper herbicides and can be used in a mixture with Reward or Aquathol K. Other chelated or compound copper formulations are available but are not linked to this web site.
Aquathol, Aquathol K, and Aquathol Super K are dipotassium salts of endothall and comes in both liquid and granular formulations. These endothall products have been effective on curly-leaf pondweed and can be mixed with copper compounds for additional effectiveness. Contact herbicides act quickly and kill all plants cells that they contact.
Hydrothol 191 is an alkylamine salt of endothall and comes in both liquid and granular formulations. It is a contact herbicide and has been effective on curly-leaf pondweed. Contact herbicides act quickly and kill all plants cells that they contact. Hydrothol can be toxic to fish.
Sonar and Avast are fluridone compounds, come in both liquid and granular formulations, and have been effective on curly-leaf pondweed. These are broad spectrum, systemic herbicides. Systemic herbicides are absorbed and move within the plant to the site of action. Systemic herbicides tend to act more slowly than contact herbicides.
One danger with any chemical control method is the chance of an oxygen depletion after the treatment caused by the decomposition of the dead plant material. Oxygen depletions can kill fish in the pond. If the pond is heavily infested with weeds it may be possible (depending on the herbicide chosen) to treat the pond in sections and let each section decompose for about two weeks before treating another section. Aeration, particularly at night, for several days after treatment may help control the oxygen depletion.
One common problem in using aquatic herbicides is determining area and/or volume of the pond or area to be treated. To assist you with these determinations see SRAC #103 Calculating Area and Volume of Ponds and Tanks.
Many aquatically registered herbicides have water use restrictions. For
General Water Use Restrictions click here.To see the labels for these products click on the name. Always read and follow all label directions. Check label for specific water use restrictions.
Cultivation Options
Curly-leaf pondweed is a non-native, invasive species and should not be propagated.
Identification
Curly-leafed pondweed is a perennial plant that is native to Europe and gets it name from the rippled or wavy nature of its submerged leaves. The leaves are alternate, oblong 3/4 to 4 inches long and ¼ to ½ inch wide. Mature leaves are toothed with a distinct midrib with paired parallel lateral veins, nearly translucent. Stems are flattened and branching. Fruits are seldom found, they reproduce from small "burr-like" vegetative structures that from a the base of some leaves. Curly-leafed pondweed can be an aggressive invader that can cover large portions of ponds.
Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called "detritus") for many aquatic invertebrates. Since fruits are not usually present on curly-leafed pondweed, it has little food value to wildlife. It is a non-native plant and should not be spread.
