Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Curly leaf pondweed

Mark, I think the curlyleaf in your pond basically reached a point where the population bloomed once the plants became abundant enough to produce a large batch of winter buds in 2005. Production of exponential or high number of turions then resulted in what appears as a big growth increase in 2006.


I have dealt with curlyleaf pondweed for numerous years in two ponds; one shallow, one deep. In the northern areas without aquashade use, it does die back around late June early July. I think Aquashade delays the growth cycle. Die back happens once the plants produce flowers and turions (winter buds). I was removing some plants tonight (June 1st) and they pulled away from the bottom easy, due to the stems near the soil were already starting to decompose/rot. Plants 2-3 weeks ago would not pull away from the bottom without the stems breaking at midplant.

During July, Aug, and Sept curlyleaf is not visible in my ponds. Previously, I have dealt with it primarily by cutting it with the Y shaped cutter. This is less practical in a 1.5 acre pond. In your case you might want to look into a Jenson Lake mower. If curlyleaf is cut in the time window of between the time it produces the 15th and 22nd branch (node) or just before it produces turions you can get effective control by cutting. If you cut the plant before it produces the 15th branch, then it will regrow (Lake & Pond Management Guidebook by McComas).

I never used grass carp to control it because I did not want them to eat other more desirable plants in my pond. I was always told that grass carp are not real afffective against it due to them not liking the plant very much due to the presence of turions which are offensive and distastful to them.

This year, I am now experimenting with controlling it with Sonar which if used properly can be a somewhat selective herbicide. Kelly Duffie is advising me on its use. I am told curlyleaf is very sensitive to low concentrations (10-15ppb) of Sonar (Floridone). I have no results yet to report.

In my ponds the curlyleaf has not been all bad since it essentually dissappears from the main water column in Jul thru Mar. The only time I fish my pond is during winter thus the weed is not that much of a problem for ice fishing. The growth that redevelops in late fall is around 6"-18" tall during fall-winter. I think this provides excellent cover for small fish during fall, winter and early spring. Abundant growth also competes well against filamentous algae in cold water conditions. I essentually have no FA (especially cold water FA algae) when curlyleaf is abundantly growing.