Pond weeds

Asked July 6, 2020, 12:31 PM EDT

Someone has told me barley straw can help get rid of pond weeds? I want a safe way to get rid of the majority of weeds in my pond, without harming fish or other species. We have 3 ducks that live in it as well I don't like the idea of chemicals but I am also tired of manually removing seaweed, duckweed and other growth by hand in roughly 3/4 acre pond that is about 14-18' deep?

Shiawassee County Michigan

1 Response

Hello and thank you for using Michigan State University Extension eXtension ask an expert for you pond question. Managing pond weeds is not as simple as just removing weeds. Barley Straw is not an herbicide and not suitable for plant reduction. It is recommended for some types of Algae. Indeed, in some cases if left in a pond, barley straw will decompose and actually contribute more nutrients to your pond further feeding plant growth.

Controlling excessive plant growth means first managing the nutrients entering your pond that are feeding the weeds. What are some of the management practices near your pond that may be contributing to this? Are you mowing to the water edge? Do you have buffer strips around your pond? Is there drainage into your pond from someplace else?

Then ask yourself why removing weeds is important. Why is it important that the pond plants are removed? Do you fish in your pond? Boat propellers getting tangled? Are they preventing swimming? Pond weeds provide food and shelter for fish. Not so much fun if you are swimming. Your Ducks feed on the weeds and grasses around your pond, while pooping nutrients back into the pond how are you manageing that? If you get rid of all of your weeds you may disrupt the food web of insects and plants for both fish and ducks to eat and shelter in.

Shallow ponds by their very nature are usually filled with vegetation. Using a dye can help with algae and submerged plants but not emergent plants or floating plants. Those plants will require manual removal or an herbicide to remove. You may also desire to choose an herbicide to kill the plants. Read and follow the label directions closely. Make sure the label indicated that the herbicide is rated for use in aquatic environments. Any place that sells pond supplies often also sells aquatic herbicides. The article listed below explains nutrient loading and ways to prevent that to reduce plant growth.

Resources:

Managing your pond

https://www.canr.msu.edu/news/preserve_your_natural_backyard_pond

this article will help you to calculate pond volume

https://www.canr.msu.edu/news/how-much-water-is-in-my-pond

about pond dyes

https://www.canr.msu.edu/news/using_aquatic_dyes_in_ponds