Rock salt is a harsh chemical compound used primarily to melt snow and ice on roadways and sidewalks. Rock salt is available in several chemical versions including the most common form, sodium chloride. The application of rock salt lowers the freezing temperature of water from 32 degrees Fahrenheit to minus 25 F. This causes ice and snow to melt away when it normally would not. The harsh characteristics of rock salt also make it an effective herbicide. Its application to areas where tree roots have become a problem, like breaking or blocking sewer pipes, can quickly kill them, making removal easier.
Place a handful of rock salt into your toilet and flush it down once every few weeks or so. If you have a tree with roots that are approaching or have reached your sewer lines, they may be breaking their way through the pipe in search of the water supply within. Flushing a bit of rock salt down the sewer will kill any roots that have already made their way inside, while preventing those nearby from getting any closer.
Place 1/2 pound of sodium chloride or copper sulfate into your toilet bowl. Flush the salt down the drain so it clears the bowl completely. Place another 1/2 pound into the bowl and flush again. Repeat the process until 2 pounds of sodium chloride or copper sulfate have been flushed into the sewer where the tree roots have become an issue. Do not use the toilet or any water that will drain into the sewer line for at least 12 hours. During this time, the chemicals will be taking effect on the invasive roots. Repeat the process every six months or so to keep the line open.
Locate the area of the root intrusion into your sewer line. Mark the location on the surface above the underground pipe. Use an earth auger to dig a hole into the ground directly above the clog. Insert a length of 2-inch PVC pipe into the hole and pour 4 pounds of rock salt or copper sulfate into the pipe. Pour 5 gallons of hot water into the pipe and allow the mixture to slowly drain into the soil where it will destroy the invasive roots and clear your sewer lines.
Things You Will Need
- Copper sulfate
- Earth auger
- 2-inch PVC pipe
- Sodium and chloride are both poisonous to plants. When combined in rock salt, they act as a sponge that sucks away any hint of moisture from vegetation, causing dehydration and death. Even high saline plants are susceptible to the effects of rock salt application.
- Rock salt is safe for use with either sewer or septic systems. Copper sulfate is not safe for septic systems.
- Use caution when working with rock salt. It is a corrosive material that can irritate skin and cause tough materials like concrete to crack and crumble. Wear work gloves and eye goggles for protection, and always wash away unwanted rock salt with plenty of water.
- Purdue University: Salt Damage in Landscape Plants
- New York Times: De-Icing With Salt Can Harm Trees
- Cornell University: Keep Your Trees on a Low-Salt Diet So Come Spring, They're Not Dying of Thirst
- Southern Agricultural Insecticides Inc: Copper Sulfate Granular Crystals
- The Complete Idiot's Guide to Household Solutions; Melodie Moore
- Ask the Builder: Avoiding Sewer Backups From Tree Roots
- San Francisco Salt Company: About Salt
- Andy Sotiriou/Digital Vision/Getty Images