Pond vegetation problems

Asked August 28, 2017, 12:26 PM EDT

I have a 2 3/4 acre pond about 18 years old. In the last 8 to 10 years, some really thick weeds or rush have started growing on the perimeter and now completely circle the bank. In the last 5 to 7 years lilies of some sort have started to take over, again starting on the bank and moving out. I have someone with a track hoe cleaning what they can reach, but there is going to be some of the weeds and lilies that cannot be dug out. Would grass carp be a good solution to further clean up and keep the vegetation from coming back? I have ask that he give me a some depth at the bank and remove some of the silt, which I am afraid is part of the problem. Any other recommendations? Thank you, Mike

Livingston County Kentucky

1 Response


You are correct in observing that the plants will establish in the shallow areas of the pond. Ideally, The pond margins should be 2.5 to 3.0 deep to help discourage aquatic vegetation from establishing. Over time, the shoreline areas erode and the plants find these areas attractive to grow in. I have attached two pond construction and renovation publications which explain these processes in detail.
The plants in the pictures appear to be be spatter dock/cow lily (water lilies) and common reed (Phragmitis sp.). Both of these may be controlled with Glyphosate (Rodeo, Aquamaster, etc.) and other herbicides listed on the herbicide fact sheet. These are both tough plants to control and will likely take repeat applications. Read the herbicide label for appropriate information. Grass carp will not control tough vascular plants like these. Grass carp will consume soft stemmed vascular plants and branched algae that are easily digested.
Thanks! Forrest Wynne

KSU State Extension Specialist for Aquaculture