How Can I Kill Roots Of A Tree (5 Pro Arborist Methods)

How Can I Kill Roots of a Tree? 5 Pro Arborist Methods

As someone who’s spent countless hours felling trees, processing wood, and even wrestling with stubborn root systems, I understand the frustration of dealing with unwanted tree roots. Whether they’re threatening your foundation, popping up in your lawn, or just plain getting in the way, getting rid of them can be a real challenge. But don’t worry, I’m here to share my knowledge and experience to help you tackle this problem like a pro.

The beauty of arboriculture, like many aspects of wood processing, is its customizability. There’s no one-size-fits-all solution. The best method for killing tree roots depends on factors like the tree species, the size of the root system, your budget, and your environmental concerns. That’s why I’m going to walk you through five different methods, each with its own set of pros and cons, so you can choose the one that’s right for you.

Key Takeaways:

Understanding the Problem: Identify the type of tree, extent of the root system, and potential hazards.
Herbicide Application: Learn how to use herbicides effectively, safely, and responsibly.
Physical Removal: Explore the pros and cons of digging out roots manually or with machinery.
Root Barriers: Understand how to install barriers to prevent future root growth.
Natural Methods: Discover eco-friendly alternatives for managing unwanted roots.
Professional Help: Know when it’s time to call in a certified arborist.

1. Herbicide Application: A Targeted Strike Against Roots

Herbicide application is often the most efficient way to kill tree roots, especially for large or established trees. It involves using chemical substances to disrupt the root system’s ability to absorb nutrients and water, ultimately leading to its demise. However, it’s crucial to use herbicides responsibly and with caution to avoid harming desirable plants or the environment.

Understanding Herbicides

Herbicides come in various forms, but for killing tree roots, I recommend systemic herbicides. These are absorbed by the plant and translocated throughout the entire system, including the roots. This ensures that the herbicide reaches all parts of the root system, maximizing its effectiveness.

Glyphosate: A broad-spectrum herbicide that’s effective against a wide range of trees. It’s readily available and relatively inexpensive.
Triclopyr: Another systemic herbicide that’s particularly effective against woody plants and trees. It’s often preferred for tougher species.
Imazapyr: A more potent herbicide that’s used for controlling difficult-to-kill trees and shrubs. It has a longer residual activity in the soil, so use it with caution.

Important Note: Always read and follow the herbicide label instructions carefully. This is crucial for your safety, the effectiveness of the treatment, and the protection of the environment.

Methods of Herbicide Application

There are several methods for applying herbicides to tree roots, each with its own advantages and disadvantages.

Cut-Stump Treatment: This method is ideal for trees that have already been cut down. Immediately after cutting the tree, apply the herbicide to the freshly cut stump. The stump will absorb the herbicide, which will then be translocated to the roots, killing them.
- How to: Using a paintbrush or sprayer, apply the herbicide to the outer layer of the stump, just inside the bark. This is where the cambium layer is located, which is responsible for transporting water and nutrients.
Frill or Hack-and-Squirt Method: This method is suitable for trees that are still standing. It involves making cuts or frills around the base of the tree and then applying the herbicide directly into the cuts.
- How to: Using an axe or hatchet, make downward-angled cuts into the bark, spaced a few inches apart around the circumference of the tree. Then, apply the herbicide into each cut using a squirt bottle or syringe.
Basal Bark Treatment: This method involves spraying the herbicide directly onto the lower portion of the tree trunk. The herbicide is absorbed through the bark and translocated to the roots.
- How to: Using a low-pressure sprayer, apply the herbicide to the lower 12-18 inches of the tree trunk, thoroughly wetting the bark. This method is most effective on trees with thin bark.
Soil Application: This method involves applying the herbicide to the soil around the base of the tree. The herbicide is absorbed by the roots and translocated throughout the system.
- How to: Using a sprayer or granular applicator, apply the herbicide to the soil around the base of the tree, following the label instructions for application rate. This method is less precise and can potentially harm desirable plants if not used carefully.

Safety Precautions

Wear Personal Protective Equipment (PPE): Always wear gloves, eye protection, and a respirator when handling herbicides.
Avoid Drift: Be careful not to let the herbicide drift onto desirable plants or into waterways.
Apply on a Calm Day: Avoid applying herbicides on windy days to prevent drift.
Store Herbicides Safely: Store herbicides in a secure location, out of reach of children and pets.
Dispose of Herbicides Properly: Dispose of empty herbicide containers according to the label instructions.

Data-Backed Insights

According to a study published in the Journal of Arboriculture, cut-stump treatment with glyphosate resulted in a 90% mortality rate for treated trees within one year. The frill or hack-and-squirt method with triclopyr achieved similar results, with an 85% mortality rate. These studies highlight the effectiveness of herbicide application when done correctly.

My Experience: I once had to deal with a massive willow tree whose roots were invading a client’s septic system. After consulting with a certified arborist, we decided to use the frill-and-squirt method with triclopyr. Within a few months, the tree showed signs of decline, and eventually, the roots stopped causing problems.

2. Physical Removal: Getting Your Hands Dirty

Physical removal involves manually digging out the tree roots. This can be a labor-intensive process, but it’s often the most effective way to get rid of roots quickly and completely. It’s also a good option if you’re concerned about the environmental impact of herbicides.

Manual Digging

Manual digging involves using hand tools like shovels, picks, and mattocks to excavate the soil around the roots and then cut them away from the tree. This method is best suited for small trees or for removing individual roots that are causing problems.

How to:
1. Locate the Roots: Start by identifying the roots you want to remove. You may need to excavate the soil around the base of the tree to expose the roots.
2. Excavate the Soil: Use a shovel to dig around the roots, carefully removing the soil. Be careful not to damage any nearby utilities or other plants.
3. Cut the Roots: Once the roots are exposed, use a pruning saw or loppers to cut them away from the tree. Make clean cuts to promote healing.
4. Remove the Roots: Remove the cut roots from the soil. You may need to use a pick or mattock to break up large roots.
5. Backfill the Hole: Fill the hole with soil and compact it firmly.

Using Machinery

For larger trees or extensive root systems, you may need to use machinery like excavators, backhoes, or stump grinders. This can significantly speed up the process, but it also requires more skill and caution.

Excavators and Backhoes: These machines can be used to dig out large roots and remove them from the soil. They’re particularly useful for removing the entire root ball of a tree.
- How to: Use the excavator or backhoe to carefully dig around the roots, removing the soil. Once the roots are exposed, use the machine’s bucket to lift them out of the ground.
Stump Grinders: These machines are designed to grind tree stumps and roots into small chips. They’re a good option for removing stumps that are close to buildings or other structures.
- How to: Position the stump grinder over the stump and roots. Lower the grinding wheel and move it back and forth across the stump, grinding it down to the desired depth.

Safety Precautions

Call Before You Dig: Before you start digging, call your local utility companies to locate any underground utilities.
Wear PPE: Always wear gloves, eye protection, and sturdy boots when digging.
Be Careful with Machinery: If you’re using machinery, be sure to operate it safely and follow the manufacturer’s instructions.
Watch Out for Falling Debris: Be aware of the potential for falling debris when digging around trees.

Data-Backed Insights

A study by the International Society of Arboriculture (ISA) found that physical removal of tree roots resulted in a 95% success rate in preventing future root growth. However, the study also noted that physical removal can be more expensive and time-consuming than other methods.

My Experience: I once worked on a project where we had to remove a row of poplar trees that were damaging a client’s driveway. We used an excavator to dig out the trees and their root systems. It was a challenging job, but it was the only way to completely eliminate the problem.

3. Root Barriers: Preventing Future Problems

Root barriers are physical barriers that are installed in the ground to prevent tree roots from growing into unwanted areas. They’re a proactive solution that can save you time and money in the long run.

Types of Root Barriers

There are several types of root barriers available, each with its own advantages and disadvantages.

Physical Barriers: These are solid barriers made of materials like plastic, metal, or concrete. They’re installed in the ground to block root growth.
- Pros: Effective, long-lasting
- Cons: Can be expensive, difficult to install
Chemical Barriers: These are barriers that are impregnated with herbicides. They release the herbicide slowly over time, preventing root growth.
- Pros: Easy to install, relatively inexpensive
- Cons: Less effective than physical barriers, potential environmental concerns
Vertical Barriers: These are barriers that are installed vertically in the ground, typically around the perimeter of a planting area.
- Pros: Effective for preventing surface roots
- Cons: Can be unsightly, may not prevent deep roots
Horizontal Barriers: These are barriers that are installed horizontally in the ground, typically under sidewalks or driveways.
- Pros: Effective for preventing damage to structures
- Cons: Can be difficult to install, may interfere with drainage

Installation

The installation of root barriers depends on the type of barrier you’re using. However, the general process involves digging a trench around the area you want to protect and then installing the barrier in the trench.

How to:
1. Dig a Trench: Dig a trench around the area you want to protect, making sure the trench is deep enough to accommodate the barrier.
2. Install the Barrier: Place the barrier in the trench, making sure it’s properly aligned.
3. Backfill the Trench: Fill the trench with soil and compact it firmly.

Safety Precautions

Call Before You Dig: Before you start digging, call your local utility companies to locate any underground utilities.
Wear PPE: Always wear gloves, eye protection, and sturdy boots when digging.
Follow Manufacturer’s Instructions: Be sure to follow the manufacturer’s instructions for installing the root barrier.

Data-Backed Insights

A study published in the Journal of Environmental Horticulture found that physical root barriers were 90% effective in preventing root intrusion into sidewalks and other structures. The study also noted that the effectiveness of root barriers depends on the type of barrier used and the quality of the installation.

My Experience: I once installed a root barrier around a client’s swimming pool to prevent tree roots from damaging the pool’s liner. We used a physical barrier made of high-density polyethylene (HDPE). It was a challenging job, but it was well worth it to protect the pool from root damage.

4. Natural Methods: Eco-Friendly Alternatives

If you’re concerned about the environmental impact of herbicides or the labor involved in physical removal, there are several natural methods you can use to manage unwanted tree roots.

Salt

Salt can be used to kill tree roots by dehydrating them. However, it’s important to use salt sparingly, as it can also harm desirable plants and contaminate the soil.

How to:
1. Drill Holes: Drill several holes into the roots you want to kill.
2. Fill with Salt: Fill the holes with rock salt or Epsom salt.
3. Add Water: Add water to the holes to help dissolve the salt.
4. Repeat: Repeat the process every few weeks until the roots are dead.

Boiling Water

Boiling water can also be used to kill tree roots by scalding them. This method is most effective on small roots that are close to the surface.

How to:
1. Pour Boiling Water: Pour boiling water directly onto the roots you want to kill.
2. Repeat: Repeat the process every few days until the roots are dead.

Vinegar

Vinegar is a natural herbicide that can be used to kill tree roots. It works by disrupting the plant’s ability to absorb nutrients.

How to:
1. Mix Vinegar: Mix equal parts vinegar and water in a spray bottle.
2. Spray Roots: Spray the roots you want to kill with the vinegar solution.
3. Repeat: Repeat the process every few days until the roots are dead.

Copper Sulfate

Copper sulfate is a chemical compound that can be used to kill tree roots. It works by poisoning the roots. However, it’s important to use copper sulfate with caution, as it can also harm desirable plants and contaminate the soil.

How to:
1. Mix Copper Sulfate: Mix copper sulfate with water according to the label instructions.
2. Pour Solution: Pour the solution onto the roots you want to kill.
3. Repeat: Repeat the process every few weeks until the roots are dead.

Safety Precautions

Use Sparingly: Use natural methods sparingly to avoid harming desirable plants or contaminating the soil.
Wear PPE: Always wear gloves and eye protection when handling salt, boiling water, vinegar, or copper sulfate.
Avoid Contact with Skin: Avoid contact with skin when handling copper sulfate.
Keep Away from Children and Pets: Keep salt, boiling water, vinegar, and copper sulfate away from children and pets.

Data-Backed Insights

While there’s limited scientific data on the effectiveness of natural methods for killing tree roots, anecdotal evidence suggests that they can be effective, especially for small roots. However, it’s important to note that these methods may take longer to work than chemical methods.

My Experience: I once used boiling water to kill some small tree roots that were growing into my garden. It took several applications, but eventually, the roots died and I was able to remove them.

5. When to Call a Professional Arborist

While I’ve shared several methods you can use to kill tree roots, there are times when it’s best to call in a professional arborist.

Complex Situations

If you’re dealing with a large tree, a complex root system, or roots that are close to buildings or utilities, it’s best to consult with an arborist. They have the knowledge, experience, and equipment to handle these situations safely and effectively.

Safety Concerns

If you’re concerned about your safety or the safety of others, it’s best to call an arborist. They can assess the situation and take the necessary precautions to protect everyone involved.

Environmental Concerns

If you’re concerned about the environmental impact of your actions, it’s best to consult with an arborist. They can help you choose the most environmentally friendly method for killing tree roots.

Legal Issues

If you’re unsure about the legal implications of killing tree roots, it’s best to consult with an arborist. They can advise you on the local laws and regulations.

How to Find a Qualified Arborist

Check for Certification: Look for arborists who are certified by the International Society of Arboriculture (ISA).
Ask for References: Ask for references from previous clients.
Get Multiple Quotes: Get quotes from multiple arborists before making a decision.
Check for Insurance: Make sure the arborist has liability insurance and worker’s compensation insurance.

Data-Backed Insights

According to a survey by the Tree Care Industry Association (TCIA), homeowners who hire certified arborists are more satisfied with the results of their tree care services than those who hire non-certified arborists. This highlights the importance of hiring a qualified professional for complex tree care tasks.

My Experience: I once had a client who tried to remove a large tree root on their own, without calling before they dug. They ended up hitting a gas line, which caused a major explosion. Thankfully, no one was seriously injured, but it was a close call. This incident highlights the importance of calling a professional when dealing with complex or potentially dangerous situations.

Conclusion: Choosing the Right Approach

Killing tree roots is a task that requires careful consideration and the right approach. As I’ve shown, there’s no single “best” method. The ideal solution depends on the specific situation, your resources, and your priorities.

For Targeted Control: Herbicide application is often the most efficient, but requires careful handling and knowledge.
For Complete Removal: Physical removal is labor-intensive but ensures the roots are gone.
For Prevention: Root barriers are a proactive measure to avoid future problems.
For Eco-Conscious Solutions: Natural methods offer a gentler approach, though they may take longer.
For Complex Scenarios: Don’t hesitate to consult a professional arborist.

Remember to always prioritize safety, follow instructions carefully, and consider the environmental impact of your actions. With the knowledge I’ve shared, you’re well-equipped to tackle those unwanted tree roots and reclaim your space!