Correcting Pond Weediness - First Steps

Introduction

Each pond is different and pond owners have different objectives. These things must be known and considered so that a good weed management plan can be made. Help your county Extension educator develop that plan by assisting with these eight areas.

 

First Steps

1. Eyes on the Pond
   If a site visit from your county Extension educator is not possible, please provide the following images or samples.
   • Photos of the pond
   • Photos of the surrounding area that drains to the pond.
   • A good close-up photo of the problem plant.
     • Take one or two plants from the pond and lay against a light-colored background.
     • Arrange to show as many characteristics as practical (leaf shape and arrangement, stem, roots, flowers, "buds" or any similar features).
     • Take the photo from about 12 inches away.
     • Include a coin, pen or ruler.
     • An alternative is a fresh plant sample delivered to your Extension educator.
       • Place your sample in a sealed plastic bag with a moist paper towel.
       • Keep it cool.
2. History of the Weed Problem
   How long has the pond had excess plant coverage?
   What has been tried to manage pond weeds and what were the results?
3. More About the Pond and Surrounding Area
   Pond size: acres or square feet.
   Percentage of pond that is less that 3 ½ feet.
   Age of the pond?
   What percentage of the pond is covered or filled by plants?
   Is there a layer of organic matter on the pond bottom with a rotten egg smell when stirred?
   Are there other aquatic plants in the pond beside the problem plant or algae?
   If there are no other pond plants, is the reason known?
   Have pond plants been eliminated with herbicides?
   Are there any of the following problems in the area that drains to the pond (the watershed)?
   • Annual manure runoff
   • Chemical fertilizer runoff
   • Heavy leaf fall
   • Large numbers of livestock
   • Areas of eroding soil (sediment can create shallow areas prone to emergent weeds)
4. Are Herbicides Acceptable?
   List any concerns about herbicides:
5. How is the Pond Used?
   Herbicides often have withdrawal times for certain pond uses. These uses may narrow the choice of herbicides.
   Pond is used for:
   • Livestock (type, number)
   • Fishing
   • Swimming
   • Irrigation
   • Household water use
   • Other objectives:
     • Attractive appearance
     • If important, are some pond plants acceptable?
6. Surrounding Areas
   Are there ponds, creeks or aquatic areas below the pond overflow point?
   If so, extra care may be needed to reduce the chance of the pond overflowing soon after a herbicide application. Describe (if any):
7. Risk of contaminating groundwater with a pond herbicide application.
   Does the pond fill from the bottom up?
   What is the depth to groundwater?
   (Depth of water wells may be an indication)
8. Applications
   Is there someone to do herbicide applications?
   Being able to apply herbicides takes into account three things:
   1. Physically able to do the application
   2. Suitable application equipment available:
      Boat
      Sprayer (distance can reach)
      Granule spreader (distance can reach)
   3. Familiar with calculating application rates and calibrating the application, equipment. (Ask for help, if needed)

 

Herbicides are not effective in the long-term. Additional management steps will usually be included in the weed management plan your county Extension educator develops.

 

When using pond herbicides, there are precautions you need to understand – see  Aquatic Herbicides: Essential Information for New Applicators.