Curlyleaf Pond Weed – FAQ

  1. What is the name of the weed that covers Queens Lake? The weed is called Curlyleaf Pond Weed (Potamogeton cripis L.)
  2. Is this pond weed native? Curlyleaf Pond Weed is an invasive species which originates from Eurasia and can be traced back as far as 1880 in Virginia. Curlyleaf is found all throughout the US but prefers the cooler climates of the northern states.
  3. What is the life cycle of Curlyleaf Pond Weed? The life history of curlyleaf pond weed is unique to submersed aquatic plants. New growth starts in late summer or early fall and continues until the water cools and the days become short. At this point plants can be several inches to a foot tall and remain dormant until the waters reach 40o and days lengthen with more available sunlight. Even before other species have broken their spring dormancy the curlyleaf grows at a rapid rate and forms a dense canopy in the water blocking out other species of plants, limiting navigation and other lake activities. At this point turions will form, the weed will bloom and form seeds and begin to die off or senescence while the turions fall to the lake bed in early June.
  4. How does Curlyleaf Pond Weed reproduce? Four different methods A. Individual plant cuttings will develop roots and form a new plant; B. fertile seed pods – often consumed and spread by waterfowl; C. rhizomes from mature plants; D. The most prevalent, the turion. Turions are a dormant shoot segments that is thickened and can remain viable in a lake bed for as long as 5 years, sprouting when conditions are favorable.
  5. How is Curlyleaf Pondweed controlled? Four different methods A. Biological – grass carp; B. Chemical – aquatic herbicides; C Mechanical – harvesting, raking, hand cutting; D. Physical – water drawdown, dredging, bottom barriers
  6. Wasn’t Queens Lake treated last year with the promise the treatment would last several years? Yes, but there is no single treatment available for Curlyleaf Pond Weed, all effective programs range from 3 to 6 years depending on the severity of the problem and include multiple control methods. Treatments should be done before new turions are produced and continue annually until the turion cycle is broken.
  7. Will we be able to completely rid Queens Lake of pond weed? No, there will always be some amount the pond weed in the lake and after the initial treatment program control would be maintained with spot treatments and grass carp.
  8. What is the next step? A bath metric mapping survey was done in May which will show all locations and densities of the Curlyleaf Pond Weed and treatment program is being developed to kill next year’s crop before it grows anywhere near the water surface. This treatment could be done as early as November and will depend on the exact method chosen.
  9. How long will we have to treat Queens Lake? We should be prepared to budget for a 4 to 6 year treatment program. The highest costs will occur in the first and second years when the treatments will be the most aggressive, and continue to decline in subsequent years. With continued lake mapping and treatments by year three we should have a clear indication when we change our program from aggressive treatment to a maintenance program.
  10. What will be the costs of a treatment plan? Final estimates for treatment plans are still being prepared but cost are expected to range for from $18 to 20k the first two years and then drop significantly in subsequent years.