Dredging is an effective solution for large-scale cattail infestation.
Cattails are among the most common invasive aquatic plants. Though they look like grass, cattails are sturdy plants that can grow to a height of around two meters. Otherwise known as corn dog grass or bulrush, cattails have long, flat leaves; and long, brown, cylindrical flower spikes that make them attractive. A few cattails near ponds and other aquatic features enhance the natural look and provide a safe haven for aquatic organisms. Though they are grown for decorative purposes, cattails may turn invasive in no time, and spread over an entire area.

Being wetland plants, cattails are often found near rivers, lakes, and ponds. Each flower spike contains more than 250,000 seeds that can germinate into new plants, if the conditions are favorable. Apart from that, the rhizome of the plant produces new shoots and roots, thereby spreading their network. Among the different species, the common cattail, the broad-leaf cattail, and the narrow-leaved cattail are mostly found in North America. If you are worried about the uncontrolled growth of cattail in your pond or premises, you may try these solutions.

Effective Methods to Kill Cattails

With a very high reproductive rate, cattails spread rapidly, and you may find it difficult to control their growth. As in case of other invasive plants, you may try to remove them manually. Another method is to use chemicals for killing cattails. This has to be done cautiously, so as to avoid harming aquatic organisms like fish. Given below are some of the commonly used methods of cattail control.

Pull Them Out By Hand
The simplest method is to remove the plants using your hands. Pull the main stem gently, so that the plant can be removed along with its roots (rhizomes). This is very important, because roots can produce new shoots. Tools like shovels can be used to pull out the roots. As cattails grow on the banks of water bodies, it won't be difficult to remove the plants from the shallow water. Remove cattails at regular intervals to control their unrestricted growth.

Cut the Stems Below the Water Surface
The leaves (including the dry ones) of cattails supply oxygen to the rhizomes. It is believed that disrupting this air supply is one of the best methods for natural cattail control. A single leaf is sufficient to provide oxygen for rhizomes that are located nearby. Cut the stems well below the water surface, so that there is no leaf left to absorb air. So, continuous removal of cattail leaves may lead to elimination of these plants. Use sharp scissors or long shears to cut the plants, as soon as they emerge from water.

Remove Them Using Machines
Machines are often used for cattail removal, especially in case of large-scale invasion. A backhoe is a good choice for removing cattails growing in large masses on the banks of water bodies. Bulldozers and cookie cutters are also used for this purpose. However, these plants develop new shoots within no time, if the roots are not removed completely. So, you need to remove them at regular intervals.

Alter Water Levels
Flood the area with enough water to submerge the plants, during spring and summer. For best results, mow down the plants before raising the water level. If the plants have four to five feet of water above them, the rhizomes will not get oxygen for producing food, and they will stop producing new shoots. This will lead to elimination of cattails from that area.

Alter Salinity
Cattails grow in fresh water. They will not survive in water with a high salinity level. So, flooding the area with seawater is found to be a useful method to get rid of cattails. In order to kill these plants, the salt content of the water must be more than 10 PPT (parts per thousand). If seawater is not easily available, you may use salt blocks. Use a salinity test kit to check the level of salt in the water. In case of low salinity, use additional salt blocks. For best results, place the salt blocks directly in between the cattails.

Use Chemicals
Most of the herbicides are not meant for aquatic plants. For eliminating cattails, you may use herbicides like glyphosate. This herbicide is claimed to be safe for aquatic invertebrates and birds, if used properly. Prepare a solution of the herbicide according to the manufacturer's instructions. Add a nonionic surfactant, so that the herbicide sticks to the waxy leaves of cattails. Spray the chemical on the leaves. It will reach the roots and kill the plants.

These are some of the effective methods to get rid of cattails. Though chemical control is not preferred, proper use of safe chemicals like glyphosate may prove beneficial for eliminating cattails without killing the fish in the pond. While manual removal is ideal for small-scale infestation, machines are required for removing large masses of cattails. It is always better to try a combination of these methods, rather than sticking to a single solution. Keep in mind that some of these methods may require permission from local authorities.