Coontail: Everything You Need to Know About this Aquatic Plant

Coontail (Ceratophyllum demersum), also known as hornwort, is a submerged aquatic plant that can be found in many freshwater ecosystems throughout North America. Unfortunately, this native aquatic plant can become problematic in our lakes and ponds as it grows too densely and creates thick mats. These mats in turn can impede water flow, which degrades the water quality, which ultimately disrupts our aquatic ecosystems. In this blog we will explore more about what coontail is, how you can identify it, its impact on our Minnesota lakes and how to remove it safely and effectively.

What is Coontail?

coontailLike we mentioned earlier, coontail is a native aquatic plant with a wide distribution throughout lakes and ponds in North America. This plant gets its name from its distinctive appearance, which resembles the tail of a raccoon. Despite lacking true roots, it has the ability to be loosely anchored to the bottom through specialized, finely divided stems. These stems are known as rhizoids, which can either be buried or free-floating.

This plant  is commonly used in aquariums and water gardens as an oxygenator, as it absorbs nutrients from the water and releases oxygen through photosynthesis. Coon tail also plays an important ecological role in our natural bodies of water. As an oxygenator, it helps to maintain healthy oxygen levels in the water, which supports the growth of other aquatic organisms. It is also an important food source for waterfowl and other animals.

In addition, this plant also has an interesting reproductive strategy. It is a monoecious plant, meaning it has separate male and female flowers on the same plant. The male flowers are located on the lower part of the plant and the female flowers are located on the upper part of the plant. However, because coontail can also reproduce vegetatively through fragmentation, it can sometimes form populations consisting entirely of one sex.


How can you identify a Coontail Plant?

If you know what you are looking for, coontail is actually quite easy to identify. However, it can often be mistaken for water milfoil, which has a similar appearance. The aquatic plant we are discussing can be identified by their distinct features that include:

  1. Appearance: This plant has long, dark green branching stems that are densely covered with small, needle-like leaves. These leaves are arranged in whorls of 5 to 12.Coontail weed The dark green leaves may turn a reddish-brown during the fall months. 
  2. Texture: The leaves of this plant feel rough to the touch due to the presence of small spines. The texture almost feels like a coarse hairbrush.
  3. Growth Habit: Coontail is a submerged aquatic plant that grows completely underwater. However, it may occasionally emerge from the surface in shallow water. Like mentioned earlier, these plants can grow up to 10 feet long and are usually found growing in dense mats. These mats can provide a habitat for fish and other aquatic creatures. 
  4. Distribution: This plant is native to North America, but it has been introduced to other parts of the world as well. In some regions, like Europe and Australia, coon tail is considered to be an invasive species. This means it can grow aggressively and outcompete native aquatic plants. This can disrupt the natural balance of the ecosystem and potentially cause ecological damage.


Is Coontail bad for Minnesota lakes?

MN Lakes

Coontail is one of Minnesota’s native aquatic plant species, and plays an important role in many aquatic ecosystems in the state. However, just like invasive species – coontail can grow very quickly and form dense mats that can become problematic for some lake activities like boating and swimming.

The dense mats that form from the coon tail plant can have several other consequences. These include: impeding water flow, degrading the water quality and ultimately disrupting the lake’s ecosystem. The accumulation on the surface of the water can create an impenetrable barrier that prevents sunlight from reaching the deeper areas of the water. This lack of sunlight creates a domino effect. First, it inhibits the growth of beneficial plants, which in turn reduces the amount of oxygen in the water. The lack of oxygen can then lead to fish kills and other ecological problems.

Another nuisance caused by an overgrowth of coontail grass is an abundance of mosquitoes. The mats can create a habitat for mosquito larvae and other aquatic pests. Not something lakefront property owners and visitors want to deal with.

Thankfully, coon tail is not considered to be a threat to our Minnesota lakes. However, it can cause some issues that need to be taken care of through careful lake management practices.


How to Properly Remove Coontail

While removing coontail from your lakeshore can improve the aesthetic value of your property, it is important to remove it in a safe and responsible manner. There are several methods to consider for removal, each with its own advantages and disadvantages. The best approach ultimately depends on the specific circumstances of your lake or pond. Let’s look at the three most common removal options. 


Chemical control is one method of removal that involves the use of herbicides to kill the plants. This treatment can be useful in large-scale infestations due to the minimal labor required. However, herbicides can have negative effects on the environment and human health if not used correctly. It is best practice to consult with a professional before using any chemical treatments for plant removal. They can ensure you are using the appropriate chemicals and applying it correctly.


Biological control is another removal method that involves the introduction of coontail’s natural enemies to reduce their population. The natural enemies often include insects and fish. This is a long-term strategy that is often combined with other control methods. While this option can be effective, it can often take a long time for the natural enemies to establish themselves in order to reduce the population of this weed.


Physical removal is the most straightforward of all the methods of control, and the most effective for small-scale infestations. This treatment requires good ole fashioned manual labor. Pulling the weeds out by the roots or even using a lake rake to help clear larger sections. Once you have removed the debris from the water by hand or with a rake, the best way to dispose of it is to compost it or toss it in a landfill. Coontail can be a valuable source of organic matter for composting, but it’s important to make sure that it doesn’t contain any seeds or plant fragments that could spread the plant to other areas. 


What does the MN DNR say about Coontail removal?


The Minnesota Department of Natural Resources (DNR) does provide us with guidance on how to control and remove coontail from our MN lakeshores. Thankfully, the MN DNR does not require permits to remove this aquatic plant from our lakes. They do highly recommend talking with the experts before any control methods are put in place.


The MN DNR states clearly that coontail plays an important role in providing a habitat for fish and other aquatic organisms in our lakes. Therefore, it is essential  to balance the benefits of this plant with the need to manage its growth in areas where it’s causing problems.



While coontail is a native aquatic plant that plays an important role in maintaining healthy oxygen levels in our lakes, it can become problematic when it grows too quickly and forms thick mats. Therefore, the removal of coontail should be done carefully through safe and responsible methods. 

At Waterfront Restoration, our team of experts can help guide you through the available options and outline our approach to restoring a weed-free lakeshore for you. With proper lake management practices, we can maintain the balance of our aquatic ecosystems and protect their health and vitality.

Call to schedule a free no-obligation in-person or virtual consultation for lake weed removal today!