Egeria is a fully submerged aquatic weed.

Egeria densa is a non-native fully submerged rooted aquatic plant that has sprawling stems that can reach up to 25 feet in length. This weed is rooted but can appear floating as many stems break off from the root. The weed has slender stems with opposite leaves in whorls of 4 to 6. Leaves found in these whorls have small teeth and will feel rough to the touch.

This aquatic plant is non-native to the United States, nonetheless, it is found in a majority of U.S. States. It can be found in ponds, lakes, calm streams, and other aquatic areas.

This weed spreads from roots and stems. Egeria spreads rapidly and can produce a new plant from each double node along a stem fragment.

This non-native plant can cause chaos in an aquatic ecosystem.

Due to the rapid expansion, caused by easy spread, Egeria dangerously affects dissolved oxygen levels in ponds. Plants release their oxygen during the daytime hours, but they respire at night. If there is an abundance of this weed, respiration will cause dissolved oxygen levels to drop rapidly. This dip in dissolved oxygen in the water will deprive fish of oxygen that is necessary for their survival, resulting in a rapid fish kill.

Rapid reproduction results in massive amounts of underwater space occupied by Egeria. This plant creates dense underwater mats of large stems. These mats disturb the habitat of fish and other underwater animals.

The mats also create difficulties in ponds and lakes used for recreation. Boats and swimmers easily break off stems of the mats causing more rapid reproduction, further increasing the issue. Egeria stems will also cause snagging in areas used for fishing.

Egeria has multiple control and removal options that are fit for different ecosystem needs. Egeria control can become time-consuming, as can any aquatic weed control if the appropriate method is not selected for the specific needs of the pond.

This weed can be controlled using physical removal. Rakes can be used to pull large mats from their roots for removal. Weed cutters can also be used to trim the long stems of the aquatic plant. This is not the best option for weed control for this plant as it will reestablish from remaining roots and stems.

This form of weed control is only beneficial for short-term control as it will become high-maintenance and time-consuming.

Biological control is an option for the management of this weed. Grass Carp can help control Egeria in small quantities. Grass Carp will eat this aquatic weed, but it is not a part of their preferred diet.

Non-toxic pond dye can help to suppress the rapid growth of this weed. Dye blocks sunlight which will slow the biological processes of Egeria, resulting in less rapid growth.

Lake mats and lake bottom blankets are other options for weed management in recreational lakes and ponds. Mats suppress the growth of submersed weeds in the designated areas where the mats are placed. Mats are a good option for recreational ponds where removal is only desired in designated areas.

Aquatic herbicides are the best option for long-term widespread control and removal of Egeria. Herbicides kill this aquatic weed down to its roots and prevent weed regrowth.

Duckweed Destroyer is the best herbicide option for Egeria. This is fast acting and will have the best fast-acting effect on this aquatic weed.

Aquathol K is another great option to control Egeria. This can be used along with copper compounds, Cutrine Plus, for greater effectiveness.

Sonar is another effective herbicide to control Egeria. Sonar is a systemic herbicide so it will act at a slower rate than the other two options of herbicides for this plant.