Using an edger to create a new border between different areas in your yard like lawns, flower beds, and walkways is usually trouble-free. However, you may encounter a common obstacle when performing this task: tree and shrub roots. So can a lawn edger cut through roots? And what happens if you do?
Lawn edgers will be able to cut through smaller roots under around a quarter of an inch thick, but anything larger could damage the tool in some way. Note that cutting through bigger roots can also lead to stress and even death of the plant.
In this article, I’ll delve further into this topic, outlining the capabilities of different edgers and offering practical tips to deal with roots in your yard to avoid damaging them.
Lawn Edgers And Their Ability To Cut Through Roots
For many homeowners, the primary concern when edging around roots is whether your chosen tool can handle the task without causing damage to the equipment. There are several types of lawn edgers, including manual, electric, and gas-powered models.
Manual edgers, such as half-moon or rotary tools, are not designed to cut through large roots. Their cutting blades are not strong enough to handle thick, woody material, and you could end up damaging the tool or hurting yourself in the process. They can however slice through very thin roots quite easily.
Electric and gas-powered edgers, on the other hand, have more powerful motors and sturdy cutting blades. These machines can cut through roots up to a quarter inch in diameter without too much trouble. Some really powerful machines though can manage roots up to half an inch thick.
However, attempting to cut through thicker specimens could lead to potential damage to your equipment.
So while some lawn edgers can handle small tree and shrub roots, they are generally not designed to cut through thick, established ones, which is a good thing as this may cause undue stress to the plant.
The Risks of Cutting Tree and Shrub Roots with an Edger
Cutting through established plant roots can potentially lead to stunted growth, disease, or even death of the tree or shrub they belong to.
Additionally, cutting large, structural supports may compromise the stability of the tree, increasing the risk of it falling during storms or high winds.
So if possible, it’s best to avoid cutting roots with an edger and explore alternative methods to maintain a tidy lawn while preserving the health of your trees and shrubs.
Identifying Roots And Planning Your Edging
Edging around roots can be challenging, but with a few strategic tips, you can maintain a clean border without causing harm to your trees and shrubs.
Before you begin edging, it’s essential to inspect the area for potential roots. Start by identifying the trees and shrubs in your yard, and note their proximity to the areas you plan to edge.
Keep in mind that roots often extend far beyond the canopy of a tree or shrub, so pay close attention to the surrounding soil. Once you’ve identified where the roots are likely to be, carefully plan your edging to avoid damaging them.
Instead of cutting the root, consider creating a raised border or using landscape edging material to form a barrier between the lawn and the root. This method protects the root and keeps your lawn looking neat.
If you cannot avoid cutting through a root, consider the following tips to minimize harm:
Tips For Cutting Roots Safely
Here are some ideas for causing the least amount of damage if you have to cut through tree and shrub roots when edging:
- Choose a location that is at least 5 times the diameter of the trunk away from the base of the tree and for shrubs, avoid cutting main roots inside the area directly beneath them.
- Use a spade or garden fork to gently loosen the soil around the root, then carefully lift it and cut any smaller roots that may be intertwined. See if you can bury the larger root more deeply to avoid cutting.
- If you must cut a main root, consider using a hand saw, pruning saw, or reciprocating saw with a wood-cutting blade. This will give you more control over the cut and minimize the risk of damaging the tree or shrub.
- Avoid cutting large roots or those responsible for providing support and stability to the tree.
Caring For Trees And Shrubs After Edging
After edging around roots, it’s essential to care for your trees and shrubs to ensure their continued health. Keep these tips in mind:
- Water the affected area deeply and consistently, as cutting roots can stress the tree or shrub and make it more susceptible to drought.
- Apply a layer of organic mulch, such as wood chips or composted leaves, around the base of the tree or shrub. This will help retain moisture, suppress weeds, and regulate soil temperature.
- Monitor the tree or shrub for signs of stress, such as wilting, yellowing leaves, or reduced growth. If you notice any of these symptoms, consult an arborist or horticulturist for advice on how to address the issue.
- Avoid applying excessive amounts of fertilizer, as this can further stress the tree or shrub. Instead, opt for slow-release, organic fertilizers that provide nutrients over an extended period.
- Prune any damaged or diseased branches to help the tree or shrub focus its energy on recovery and growth.
Alternative Edging Options To Avoid Cutting Roots
If you have a lot of tree and shrub roots in your yard, you may want to explore alternative edging options that don’t require cutting roots. Here are a few ideas:
- Use flexible landscape edging materials, such as metal or plastic, to create curves and contours around roots. These materials are easy to install and can be adjusted to accommodate growing roots over time.
- Install pavers or bricks as an attractive border that can be arranged to avoid roots while still providing a crisp, clean edge.
- Consider installing a low, decorative fence to separate different areas of your yard without disturbing your trees and shrubs.
- Plant ground cover or low-growing perennial plants to create a natural border that is both attractive and protective.

Final Words
While some lawn edgers can cut through small roots, they are generally not designed to handle thick, established ones, which is not a good idea to cut anyway.
To protect your trees and shrubs, it’s essential to plan your edging carefully, employ safe techniques, and provide proper aftercare.
By considering alternative edging options and taking a mindful approach, you can maintain a beautiful yard without compromising the health of your trees and shrubs.