What Will Kill Tree Roots in a Septic Tank?

Spreading tree roots

Tree roots often invade septic tanks and block lateral lines or clog sewage flow. According to the Oklahoma Cooperative Extension Service, applying copper sulfate will kill tree roots in a septic tank and in sewer lines.

Features

Copper kills tree roots. Copper sulfate is a crystalline form of copper that dissolves in water and is absorbed by the roots.

Significance

Copper sulfate is easy to use and readily available at drugstores, garden centers and plumbing shops.

Function

Flush the copper crystals down a toilet according to package directions. When septic tank lines are root-blocked, add copper sulfate to the distribution box between the septic tank and lateral lines.

Benefits

The Extension Service reports that copper sulfate kills the roots for a short distance without harming the tree. The chemical also kills organisms that cause bad odors in septic tanks.

Considerations

Copper sulfate is corrosive. Do not use it in thin metal pipes or sinks.

Caution

Read label warnings. Copper sulfate causes skin irritation. Do not use copper sulfate in or around drinking water for people or animals.

References

• Oklahoma State University: Tree Root Control

Resources

• University of Georgia: Septic Tank Maintenance and Care