Killing Tree Roots Yourself Is Easy—Here's How to Do It
The Spruce / David Beaulieu
Removing a tree from your yard is a big job and only half the work. Whether you take on the project or turn it over to a tree removal company, you'll be left with a stump and roots.
Taking out the stump usually solves the problem of remaining roots and some companies will grind out stumps and roots for an additional fee. But if cost is a factor and you're able to put in the effort, there are safe and efficient ways to eliminate unwanted roots yourself.
Why You Might Need to Kill Tree Roots
Tree roots that grow where you don't want them to create hazards and cause damage to existing structures, utilities, and hardscape. Roots can infiltrate your water lines, septic system, and other underground utilities. They can cause heaving and cracking underneath driveways, sidewalks, patios, and building foundations. Large surface roots become a tripping hazard and damage mower blades.
You may want to initiate a landscape or home improvement project where large tree roots present an impediment to the intended work.
Want more gardening tips? Sign up for our free gardening newsletter for our best-growing tips, troubleshooting hacks, and more!
Warning
Killing the roots of a living tree damages the tree and eventually leads to death. If you want to keep the tree, call a professional for advice about managing problem roots.
How to Kill Tree Roots: 6 Ways
Some methods give immediate results while others take more time. The more physical labor you apply, the faster you'll be rid of unwanted roots.
Digging
Manually digging out roots gives the quickest results. This method can be physically challenging depending on tree size and is usually done when a stump is removed. You'll need a shovel and other tools depending on root size. These may include a mattock, axe, chainsaw, hand saw, or lopper.
The first step is to identify and mark any adjacent underground utilities.
Next use a shovel to dig a trench around the stump.
Loosen and lift attached tree roots with a pry bar.
Use the chain saw or hand saw to cut roots from the stump.
Follow the length of the root continuing to pry it up.
Use the shovel to dig the loosened roots out of the ground.
Large extensive roots may need to be cut into smaller sections to lift out and discard.
Cutting
Cutting through large roots at intervals makes the work less physically challenging but, unless you also dig them out, it takes time for them to decay and compost.
Start by tracing the root from the stump outward.
Use a shovel to dig around roots to make space for your cutting tool.
Depending on root size you may need a chainsaw, hand saw, axe, or lopper.
Cut through the entire root at intervals. Elevate the root, when necessary, to avoid cutting into the soil.
Roots can be lifted out and discarded or left to decay.
With Salt
Killing tree roots with salt can take several months but is relatively labor-free. Rock salt and Epsom salt are the most effective. Keep in mind that all salts can remain in the soil, damaging the surrounding ecosystem. Used correctly, Epsom salt desiccates and breaks down the root. Rock salt causes a fungus to develop that accelerates decay.
Rock Salt
Drill multiple holes in the root.
Fill the holes with rock salt.
Cover the root with a layer of soil and cover that with mulch.
Water the area well and keep it moist.
Epsom Salt
Drill multiple holes in the root.
Fill the holes with Epsom salt.
Cover the root with a black tarp.
Tarp and Fertilizer
Starving the roots of oxygen takes a long time but is one of the easiest ways to initiate decay.
Drill holes in the root and fill them, liberally, with high nitrogen fertilizer such as ammonium nitrate or urea.
Cover the root with a black tarp secured to the ground.
Roots begin to decay in several months.
Herbicides
Use herbicides with care so as not to damage existing plant life in the surrounding area. Herbicide with a 41 percent concentration of glyphosate works best.
Drill holes in the roots and fill them with a 50/50 mix of water and herbicide. Avoid overflow onto surrounding grass or plants.
Drill enough holes to distribute herbicide through the entire length and width of the root.
Roots should disintegrate in about two weeks.
How to Fix Your Landscape After Tree Root Removal
When roots are removed in conjunction with stump removal, fill the remaining hole with dirt, rocks, and other natural debris.
To repair the area affected by killing roots, remove debris left behind and add topsoil if needed to level the area. Sow grass seed or add mulch or gravel according to your preference and intended use of the area.
How Much Does it Cost to Remove Tree Roots?
The average cost of tree root removal is around $550 but can range between $300 and $800 depending on the size and number of roots.
When to Call a Professional
When offending roots are close to or have infiltrated utilities or damaged hardscape it's best to call a professional. Tree removal companies can often repair damage in conjunction with killing the roots. If you hope to keep the tree, a professional may offer ways to get rid of problem roots with the least damage to the tree.
Frequently Asked Questions
Does boiling water kill tree roots?
Sometimes. This method is most effective on smaller roots. The goal is to scald the entire root causing it to die and decay. Repeated applications may be needed.
Does vinegar kill tree roots?
Used in combination with salt, vinegar can help break down unwanted roots. By itself, it is unlikely to be effective.
What is the fastest way to kill tree roots?
The safest and most effective way to get rid of large unwanted roots is to call a professional. To do the job yourself, digging them out gives the most immediate results.
Read the original article on The Spruce.
