Pond Weeds Identification: A Guide from a Pond Specialist

Are pond weeds taking over your shoreline, clouding your water, and ruining your fishing experience on the water?

You’re not alone!

I’ve seen it hundreds of times. A peaceful pond starts to look more like a swamp. Boats can’t move freely, and lures are tangled with weeds. Fish populations suffer. And what used to be a recreational escape becomes a frustrating, algae-smothered mess. The real problem? Most people don’t even know which plants are causing the chaos.

Let’s fix that.

Why Proper Pond Weed Identification Is a Game Changer

Before you treat anything, or worse, apply the wrong herbicide, you need to know what you’re dealing with. Pond weeds aren’t just “weeds.” Some are harmless natives that support aquatic life. Others are aggressive invaders that can quickly choke out your pond’s ecosystem.

Misidentifying pond weeds can lead to wasted money, damaged fish habitats, and even more weed growth. That’s why accurate identification is the first and most important step in any pond management plan.

SPECIAL NOTE:

The single best way to ID an aquatic plant that you are concerned about is to contact someone who knows these plants.  Reach out to a pond biologist, like myself (sales@midwestponds.com) or your local university extension or state department of natural resources. 

Take a bunch of pictures and shoot me an email, we’ll get to the bottom of your pond plant issues and set you on the road to a better aquatic future in no time.

Knowing the name of the offending plant is truly half the battle.

Now, let’s dive into what you need to look for.

How to Identify Common Pond Weeds (The Right Way)

Pond weeds typically fall into three main categories: floating, submerged, and emergent. Each behaves differently and requires a different control strategy.

Let’s start with floating weeds. These are the plants you’ll see drifting on the surface, often forming mats that block sunlight. Duckweed and watermeal are two of the smallest culprits (but largest offenders)—tiny green specks that multiply fast. These native aquatic plants show up in old ponds that have a heavy nutrient load. Control is normally achieved through a combination of pond aeration and chemical control.

(gobotany.nativeplants.org)(ar.inspiredpencil.com)

For an in-depth discussion on duckweed pros and cons as well as control methods, please read:

Do Ducks Eat Duckweed in Ponds? A Practical Guide to Duckweed: Benefits / Downsides and Management

For our southern readers, you’ll often come into contact with water hyacinth and giant salvinia, which can form dense, floating jungles that prevent oxygen exchange and light penetration.

(invasive.org)(palestineherald.com)

Both of these invasive floating plants were introduced through the aquarium and backyard koi pond industries.  When contained, these plants suck up a ton of nutrients and multiply like mad, a great biofilter. Alas, Kevin dropped them into a river/lake in FL and TX, and now we have runaway hyacinth infestations as far north as southern IL. Way to go, Kevin!

Large-scale chemical control and physical harvesting are the best current control methods for these two heinous offenders of our biologically diverse aquatic sanctuaries. If they get into your pond, either kill ‘em dead or be diligent in raking them out. They will get out of hand, and that will lead to an expensive chemical treatment to knock them down. The frost of a northern winter keeps them at bay for now, for those of us living in the land of ice and snow.  Let’s hope the ice wall keeps them contained forever….

(wallpapersden.com)

Submerged weeds are sneakier. They grow entirely underwater, and by the time you notice them, they’ve usually taken over. American pondweed, for instance, has long, flexible stems with floating leaves.

Read all about American pondweed, ID, and control in an action-packed article called:

American Pondweed Control: How to Manage Growth Without Harming Your Pond

Hydrilla and curly-leaf pondweed have telltale textures—Hydrilla with its serrated leaf edges and curly-leaf with its ruffled lasagna-like appearance. These are often the hardest to spot until they start interfering with fishing lines or boat motors. Invasive plants usually form large matted stands and really become a problem. Here are a few pics of the most common transgressors…

Hydrilla

(fingerlakesinvasives.org)(cal-ipc.org)

Curly-leaf Pondweed

Eurasian Watermilfoil

(ar.inspiredpencil.com)(vermontlakes.org)

Then there are the emergent weeds—the ones that stick up out of shallow water or around the edges. Think cattails or arrowhead plants. While some emergents are beneficial, others, like creeping water primrose, can take over shorelines quickly and ruin aesthetics. 

Pond lilies, water shield, phragmites, and yellow floating heart are other examples of emergent aquatic plants that commonly grow to nuisance level or worse.

For tips on controlling emergent and submersed weeds like curly-leaf pondweed, eurasian watermilfoil, cattails and others, please read below:

Common Invasive Pond Weeds and Tips for Control

But here’s the kicker…

Even an experienced pond owner can struggle to tell the difference between a native plant and an invasive one. That's why using photos, comparing plant structures, and sometimes even consulting a local extension service or pond expert is essential. Take a few pictures and send them my way, I'll let you know if it's a critter worth worrying about.

Why You Should Care About the Right ID

When you correctly identify pond weeds, everything changes.

You can apply targeted solutions, rather than wasting money on treatments that don’t work. You protect fish and wildlife by keeping the right plants in balance. And most importantly, you reclaim your pond for what it was meant to be: a clean, beautiful space for recreation, relaxation, and habitat support.

Imagine pulling up to your dock and seeing clear water. The boat glides smoothly. Fish are biting. No tangles. No algae mats. No stress.

That’s what smart, science-backed weed management can deliver. And it all starts with proper ID.

Here’s What to Do Next

Ready to get serious about controlling your pond weeds?

Start by observing your pond throughout the season. Take clear photos of the plants you see, especially the leaves, stems, and how they grow (floating, submerged, or emergent). Then, compare your findings using trusted identification tools like the Texas A&M AquaPlant database or Natural Waterscapes ID guide, or contact me or another pond professional in your area. We are here to help; call on us to use our experience to help you gain back the beautiful pond/lakeshore that you deserve.