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How do I control pond weeds that return after herbicidal treatments?
Ask Our Pond Experts
Ask Our Pond Experts

How do I control pond weeds that return after herbicidal treatments?

Asked By: Barney of Andalusia, AL

A: Aquatic weed control is a tricky task. Despite dosing them with aquatic herbicides to clear your pond or lake of plant pests, weeds can grow back with a vengeance. It seems like a never-ending cycle! Why does this happen, and how do you break the cycle?

Aquatic Herbicide to Kill Pond Weeds

Herbicidal aquatic weed treatments offer benefits and drawbacks to controlling pond and lake weeds. On one hand, they work great as a quick fix to decimate actively growing weeds. Diquat aquatic herbicides like Airmax Ultra PondWeed Defense eliminate submerged, floating, and emergent weeds. Fluridone aquatic herbicides like Airmax WipeOut PondWeed Defense target floating and submerged weeds. These chemicals are effective, short-term treatments for controlling actively growing weeds.

Once those plants die, they become a food source for weeds and algae, fertilizing the future plants you want to prevent. Herbicides don’t address future growth, so you're left with yet another generation of pond weeds. If you only treat them with aquatic herbicides, this process repeats, and around you'll go again! For successful pond and lake weed control, these reactive approaches should be combined with proactive prevention.

How to Stop Pond Weeds From Growing

A balanced pond ecosystem requires a three-pronged approach to aquatic weed control: React, Prevent, and Aerate. First, identify your pond weeds to ensure you choose the correct reactive treatment. After you react by killing pond weeds, follow these tips to help keep them from returning:

Remove Dead Weeds

Once the weeds have browned, use a  Razer Rake or PondSkim Debris Skimmer to remove as much dead vegetation from the water as possible. This prevents dead plant material and muck from accumulating and fertilizing future weed growth.

Add Beneficial Bacteria

You can’t skim out everything, and debris will still find its way into your pond. Break down organics using beneficial bacteria that digest excess nutrients before they feed new weeds.

The ClearPAC Plus Pond Care Packages include the products you need to supplement beneficial bacteria populations. PondClear digests suspended debris, and MuckAway eats accumulated bottom-of-the-pond debris, naturally breaking down organic material.

Install Aeration

If you don't have one already, install an  Airmax Aeration System sized for your pond or lake. By circulating and adding oxygen to the water column with an air pump for pond aeration, the beneficial bacteria will thrive. In turn, they'll eat through even more debris, preventing weed and algae growth.

Shade and Color

Pond Dye packs another offensive tactic in your battle against aquatic weeds. Pond dye shades the water, preventing sunlight from reaching weeds sprouting on the bottom.

Throughout the spring and summer, weeds will grow. But with reactive and preventative pond management practices, you can keep those pesky plants to a minimum.

Aquatic Weed Control Questions

These pond weed control tips should have you on the right path to a weed-free aquascape. If you are still struggling with uncontrollable aquatic weeds, contact our experienced pond professionals for personalized advice at 866-766-3435.

Ready to read more pond weed maintenance advice? Explore the following articles and guides:

Identify Your Weeds
To Treat or Not to Treat
How to Treat Pond Weeds
Removing Dead Vegetation
How to Reclaim Your Lakefront Shoreline

Last Updated: March 7, 2024