When tree roots find their way into your sewer or water lines and cause issues with your drain, acting fast is key. Here's how to kill tree roots and fix the problem.
How Do You Kill Tree Roots? Proven Methods and Tips
Updated on Jul. 30, 2025
It’s true—tree roots can sneak their way into buried water lines and plumbing pipes, interrupting the flow into and out of your home.
“Tree roots respond to the sound waves of water and will seek it out,” says Lou Meyer of Davey Tree Company, which offers tree services throughout the nation. “If there’s the tiniest crack in a pipe, they will capitalize on that to get to the water. I’ve seen sewer lines completely clogged.”
The sound of gurgling from your household drains is one sign tree roots may be clogging your pipes. When foul odors or squishy areas in your yard near the septic lines accompany the gurgling, there’s a good chance tree roots are the problem.
While it’s not always an easy fix, there are several measures available on how to kill tree roots, along with ways to prevent future problems. Here’s what you need to know:
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Effective Methods for Killing Tree Roots
When plumbing issues arise, homeowners are always on the lookout for quick and effective solutions. Tanya Klein of Anta Plumbing And Drain Services in Toronto, Ontario, recommends several chemical means to clear tree roots from pipes.
Using chemicals to kill roots
- Foaming root killer with dichlobenil: “It stops root growth, kills the root in the pipe and prevents regrowth,” Klein said. “It is activated when it has contact with water and is simple to use. All you do is pour it into your toilet and flush.” This chemical root killer is a go-to for tackling root invasions effectively.
- Copper sulfate: “You can find it at any hardware store,” Klein explains. “Just pour it down your toilet and flush. It typically takes a few hours to work.” However, Klein points out that copper sulfate is a toxic substance banned in certain areas, so always check local regulations. “It can pose risks to pets and people who come into contact with it,” she warns.
Natural alternatives for managing tree roots
- Rock salt: “The safest way, and the way I prefer, to get rid of tree roots from pipes is old-fashioned rock salt that you buy cheaply from any grocery store,” Klein says. “It draws out moisture from the roots, and they eventually dry up. You will need about two pounds of salt to flush down your toilet. Don’t use that toilet or flush again for about 12 hours.” This natural solution is a great non-toxic option for killing tree roots in pipes.
When to Call in Professional Help
If the blockage is severe, consider hiring a pro to try one of these mechanical means to clear the tree roots.
- Hydro-jetting: “Hydro-jetting is a highly effective method that utilizes high-pressure water to disintegrate and flush out tree roots,” says Ben Gold of Recommended Home Buyers, who frequently handles this situation while refurbishing homes. “It’s a non-invasive approach that not only clears the immediate blockage but also prevents future root growth.” Definitely leave this method to a pro, Gold says.
- Mechanical auger: “While effective, it’s important to note that this method may require professional assistance and can sometimes cause damage to aging pipes,” Gold says.
How to Install a Root Barrier
Once the tree roots are removed and the drains are flowing again, it makes sense to stop root regrowth. Plus, it’s important to protect the tree because long-term exposure to the chemicals mentioned above can kill it. “We don’t want to take out a healthy, happy tree,” Meyer says. “You can put a root barrier in place.”
Typically made of high-density polyethylene (HDPE), root barriers are used along foundations, sewer and water lines, as well as near sidewalks or patios prone to root issues. Once in place, it’s a permanent solution.
This is how you can install one of them:
- Step 1: Dig down to the water or sewer line, wherever the roots are a problem, and prune the roots away from the area with sharp loppers or a saw. Continue to dig a trench approximately 24 to 30 inches deep to accommodate the root barrier.
- Step 2: Place the root barrier in the trench. Some root barrier products have interlock to create a solid structure, while some are completely pliable and can wrap around the area. Use what works the best for your situation. Extend the barrier to just above the soil surface to prevent the roots from bypassing it. Also consider adding mulch or gravel to keep the area neat and tidy.
- Step 3: Backfill the area.
Forward Thinking
“Roots can be a problem, but please don’t let that stop you from planting more trees,” says Meyer. “They are a wildly important asset to our environment. We love trees and want more of them.”
Be sure to choose the right trees for the landscape and give them plenty of room. Meyer says trees that naturally grow near water like cottonwoods, sycamores, river birch or weeping willows should be kept farthest from any potential water source. Instead, consider smaller trees like dogwoods or redbuds.
Medium-sized trees, like red maples or black gum trees, are well-suited to be 10 to 15 feet away from a foundation or water lines. Larger trees like oaks, hickories or tulip poplars, need at least 20 feet away from structures.
If you can’t avoid having a large tree in an area that might be an issue decades down the road, install the root barrier now to head off a future problem. It just takes some forethought to maintain healthy, beautiful trees in your landscape, with no root issues.
FAQ
What is the best way to kill tree roots permanently?
The top solution to permanently killing tree roots is with the use of potent chemical root killers such as azide foaming root killers or copper sulfate. These solutions both destroy roots in the existing pipe and discourage further root growth. If you want a more lasting solution, you could also put in a root barrier. Just eliminate the tree roots to prevent them from getting to your plumbing in the future.
How long does it take to kill roots after tree removal?
The amount of time it takes to kill tree roots post-removal can be as short as several days to several weeks. Chemical root killers can take hours or even several days to begin to work, while natural treatments like rock salt may require more time. It is important to follow up with methods to inhibit regrowth of the roots, like root barriers, to avoid future problems with your plumbing.
About the Experts
- Tanya Klein is the CEO of Anta Plumbing & Drain Services, a Toronto certified drainage contractor, offering plumbing and drainage cleaning services for commercial and residential customers in the Greater Toronto Area. She has steered Anta Plumbing to its reputation as the leader in trenchless water main and sewer line installations, and 24 hour emergency response service.
- Ben Gold is the owner of Recommended Home Buyers, a real estate investing company in Baltimore, and helps homeowners sell their homes quickly and easily. Recognised for his honest, customer-centric service, Gold ensures all home sellers are provided with straightforward, easy to understand assistance and advice when selling their property.
- Lou Meyer is a Regional Business Developer at The Davey Tree Expert Company, which provides tree care, grounds maintenance and environmental consulting services throughout the U.S. through its Davey Commercial Landscape Service. His efforts contribute to the advancement of sustainable tree care and improved health of urban greening as part of Davey Tree’s mission.
Sources:
- Recommended Home Buyer: “About Ben Gold”
- Davey Commercial Landscape Service: “About Lou Meyer”
- Anta Plumbing & Drain Services: :About Tanya Klein”
