Large tree roots can be very annoying if they grow uncontrollably around the house or under sidewalks that are frequented by pedestrians. Controlling the roots while keeping the tree alive is not an easy task and requires regular maintenance. Usually, the best course of action is to kill the entire tree and replace it with a species with less aggressive roots.
Step
Method 1 of 5: Killing Invasive Roots in the Ground
Step 1. Cut off the roots that are causing minor problems
Although it requires a lot of effort, this method can solve the problem directly without risking nearby plants. First, dig up the soil around and under the roots, then cut with a saw or garden shears. Aggressive cutting of the roots can degrade the tree's long-term function, which can lead to it dying years later. Follow these rules to prevent this:
- Multiply the diameter of the tree by 8. This is the minimum distance between the stem and roots that can be cut so as not to harm the tree.
- Cut the roots only on one side of the tree, especially if you can only cut shorter than the minimum distance.
Step 2. Dig a trench to block the roots
One time cutting the roots can only be used as a temporary solution. To prevent root problems in these areas, you may need to dig a trench and trim the roots annually, or twice a year if the roots are aggressive. You don't have to do this every year by digging a deep trench (ideally throughout the topsoil), then installing one of these barriers before returning the soil to the trench.
- Galvanized metal roofing material. Fold the edges to remove the dangerous and sharp edges.
- Two layers of HDPE plastic. Arrange these root barriers at least 30 cm long so that no roots can escape. You can sometimes get this plastic for free at animal feed stores.
- For best results, use a commercial root barrier that has been added to the herbicide. The product that is often used is Trifluralin, and this ingredient does not harm nearby plants.
Step 3. Kill the sucker with herbicide
In response to root pruning or other damage, some trees will produce new stem shoots from their root system. To kill these stem shoots separately, cut the roots to prevent the herbicide from spreading to the main tree. Spray herbicides containing glyphosate or triclopyr amine, being careful not to touch nearby plants. Many stem shoots grow aggressively. If you do not plan to kill the main tree, repeat this treatment or remove the stem shoots by hand periodically.
If the main crop has been cut down, but stem shoots are still appearing in the yard, you may need to use a herbicide for broadleaf weeds. This type of herbicide will kill all plants in the area. Repeat every time there are stem shoots that appear until the roots do not get nutrients
Step 4. Replace damaged pavement with mulch or crushed stone
You won't be able to kill the large roots that are on the surface without killing the entire tree. If it is impossible for you to kill the tree, install an impenetrable surface for the tree's roots. Because it cannot kill roots, this method cannot protect garden areas or drainpipes.
- Disassemble the damaged concrete carefully so as not to damage the roots.
- Cover the area with a geotextile cloth. Leave about 15 cm of soil around the trunk, or 30 cm if the tree is large.
- Cover it with gravel (rock fragments) that is about 8–10 cm long or coarse mulch about 15–20 cm long. Mulch is actually not very effective because it can be washed away by rain.
- Place the rocks at the edges to prevent the gravel or mulch from shifting.
Method 2 of 5: Treating Roots in Sewer Pipes
Step 1. Pour copper sulfate or coarse salt into the toilet
This is the easiest method, but has the potential to kill entire parts of nearby trees or plants. Pour in one of these products kg or less at a time, until you have poured all of them (about 1 kg). Do not run water down the drain pipe for 8–12 hours to give the salt a chance to kill the roots. Follow all safety instructions listed on the product packaging.
Both of these chemicals can cause great damage to life in the water. Their use may be restricted by your local government, especially if you live near a water treatment plant.
Step 2. Use a foaming herbicide to treat the drainpipe
This herbicide will expand and fill the pipe before it splits, making it a good option for root removal in sewer pipes. Contact herbicides kill the roots quickly upon contact, whereas systemic herbicides take weeks but can kill an entire tree. Various levels of foam viscosity have been adapted to different pipe sizes. So, read the product packaging before you buy it.
- Some herbicides are toxic to fish and other wildlife. Product packaging usually includes its impact on the environment and information on how to reduce it.
- For best results, hire a professional plumber to apply metam-sodium. These corrosive chemicals should be used by trained persons and wearing safety equipment.
Step 3. Hire a professional to remove the blockage mechanically
If the drain pipe is completely clogged with roots, the chemicals won't be able to get through. Hire a plumber to clean the pipes using a Roto Rooter or similar mechanical device. You also get the added benefit of not having to deal with herbicides that have an impact on the environment.
Step 4. Repair the drain pipe
Unless you don't mind repeating this treatment regularly, root-cleaned tubing will require structural repairs to prevent roots from growing back. By installing the lining in the pipe, you no longer need to dig to trim the roots. However, replacing the pipe completely is usually less expensive.
You may also need to remove or remove any large trees that are near the pipes. Otherwise, the roots will continue to grow into the drainpipe
Method 3 of 5: Physically Removing a Stump or Tree
Step 1. Find information about your tree first
Some tree species may produce stem shoots, which will produce new trunks some distance from the stump. Removing tree trunks will not kill the roots, and may even trigger the growth of new plants. Do not use this method on the tree species below (but this is not an exhaustive list):
- Elm, plum, cherry, and lilac trees can grow new plants from the roots after the main trunk is damaged. Use herbicides to deal with it.
- Aspen, sumac, poplar, and black locust trees can form "clonal colonies" of multiple trunks when the plants are growing normally. The roots are very difficult to treat even if you have used herbicides. Ask your local agricultural service for advice on appropriate herbicides to treat tree species in your area.
Step 2. Cut down the tree leaving the stump
If the tree needs to be cut even shorter, cut it down and leave the trunk about 90–120 cm above the ground. This will help you to have enough room to grip and pull the stump out of the ground.
Warning:
Cutting down trees is a very dangerous activity. If you don't have the experience and the right equipment, trees can fall in unwanted directions. If you've never cut a tree before, hire a professional.
Step 3. Dig up the tree stump
Dig around the stump using a shovel, pickaxe, crowbar, or backhoe (digging tractor). Cut off the largest roots with a saw or ax when the roots are visible. Clear an area within a radius of 120 cm around the tree, or as needed to cut off the main roots.
- Before sawing off the roots, place a board under them. This is useful for protecting the saw from being exposed to rocks and dirt.
- As the hole deepens, spray the area with a hose or pressure washer to reveal more roots.
Step 4. Attach the winch to the stump
Most stumps can be safely removed manually, especially if the tree has just been felled. Secure the winch to the stump, then attach the rope to a tree or car.
Step 5. Pull the winch slowly
Even a hand-drawn hoist can send a stump flying with lethal force when the stump is uprooted from the ground. Pull with short, slow forces to prevent this from happening. If you're towing it by car, move the vehicle back and forth alternately. Ideally, the stump will be lifted off the ground gradually, and fall gently beside it.
Step 6. Grind the stump if necessary
A large stump may not budge even if you lift it. If this is the case, rent a stump grinder (or hire a professional). These machines are dangerous so you should wear protective goggles and ask a grinder rental place to train you. Basically, the process of using it is like this:
- Remove any rocks near the stump that could damage the grinder's wheels.
- Position the grinding wheel a few inches above the very front of the stump.
- Start running the grinding wheel, then slowly lower it about 8 cm toward the stump.
- Gently move the grinding wheel from side to side to cut the stumps to a depth of 10 centimeters. Repeat on the next section of the stump until the surface is even.
- Repeat this process until the entire stump is ground, at least 20–25 cm below the ground, or deeper if you want to plant a new tree there.
Step 7. Fill in the blanks
Remove any remaining tree roots and fill the hole with soil. Plant the top with grass and water the soil. Now, you have a treeless area that blends into the yard. Tree roots will not grow anymore and eventually rot.
Method 4 of 5: Applying Herbicide to the Stump
Step 1. Understand the risks
Roots of the same tree species can usually grow together on contact. This means, herbicides applied to one banyan tree can spread through the roots and can kill other banyan trees in the same area. This is especially true of tree species that can form "clonal colonies," such as aspen trees and black locusts.
Step 2. Select the desired herbicide
Herbicides containing glyphosate or the amine triclopyr are very effective at killing trees and can be found in farm stores. The tree species you have will probably respond to one of these ingredients more than the others. For example, glyphosate may be more effective against olive trees, whereas triclopyr may work well against locust, maple, oak, and willow trees.
- Triclopyr amine will work best at a concentration of 8.8%. With glyphosate, try to use it at a concentration of about 40%, then dilute it with an equal amount of water. If you can't get it, use an undiluted product with a concentration of at least 20%.
- Herbicides containing 2, 4-D, picloram, or dicamba are particularly risky because they can spread to nearby plants and kill them. This will not happen if you use glyphosate or triclopyr with caution.
Step 3. Put on safety gear
Follow the directions on the herbicide package to avoid exposure to hazardous chemicals. At a minimum, you should wear long-sleeved pants and shirts, shoes that cover your toes, nitrile or latex gloves, and safety glasses. Choose clothes that are no longer used.
You do not need to wear a mask because the herbicide is not sprayed into the air
Step 4. Apply herbicide to the stump
This treatment will prevent all or most of the roots from spreading and producing new stem shoots after the tree is cut. You do have to make a new cut on the surface. However, as long as the tree is cut less than a few weeks in advance, you can make a new cut:
- Cut the stump near the ground. Make sure the pieces are even so the herbicide doesn't run into the soil. Remove any remaining sawdust.
- Use an old brush to apply the herbicide just inside the bark ring. This is where there is living tissue that will carry the herbicide to the roots.
- Dispose of empty brushes and herbicide containers in a hazardous waste disposal site.
Method 5 of 5: Applying Herbicides to Plant Stems
Step 1. Use herbicide to kill the tree
This is an easy way to cut down trees, although it may not be safe because dying tree branches and branches can break and fall on the road. In addition, this may not be applicable to trees that contain a lot of sap because the tree will release and dispose of herbicides. If you don't have this problem, apply the herbicide using the "hack and squirt" method:
- Make a downward cut into the trunk at a 45º angle to make a wedge.
- Insert the nozzle of the spray bottle directly into the wedge. Press the trigger of the spray to release a small amount of the herbicide, and try not to hit the outside of the wound.
- Read the directions on the herbicide product packaging to find out how many slices to make, and the amount of herbicide to use in each slice (usually 1 ml or less).
- Some very aggressive tree species require girdling, and require you to apply herbicide to the wood that has just opened the bark.
Step 2. Remove dead wood
A few days or weeks later, the tree's branches will begin to wither and fall. When pieces of dead wood fall, you must remove them and throw them away.
Some trees or root systems may need several coats of herbicide to penetrate the wood. If the tree still doesn't die, check the herbicide package for instructions for use. Make a new cut in the bark of the tree with each application of the herbicide
Step 3. Take the stump
If the tree is dead, dig up the stump with a shovel or backhoe. Remember, you may have to wait years if you let the tree rot on its own. So you don't have to wait that long. Be sure to remove the entire stump so that the roots don't grow back.
Tips
- To keep the tree healthy, you should maintain a balance between the top of the tree and the roots. Cutting roots close to the trunk (a few centimeters apart) will damage up to a quarter of the tree's root system. This is why the tree will die if you kill the roots.
- To prevent future root problems, find out what kinds of trees do well in your area before planting trees. You should also know the root system of the tree you want to plant. Some types of trees (eg banyan and tamarind) can cause root problems and are not suitable for planting near houses or next to sidewalks.
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There are several ways to kill a tree or stump which are very slow and even very ineffective for controlling roots:
- Trimming, or removing the bark in a deep and circular manner, will cut off the flow of nutrients from the leaves to the roots. Unless you combine it with a herbicide method, it can take years to kill a large tree.
- Covering the roots around the trunk with mulch makes the tree stressed and susceptible to disease. This method can take years to kill the tree.
- Burning the stump or backfilling it with compost or fertilizer are slow cleaning methods. For example, burning the stump takes longer than other methods because you have to wait for the stump to dry first.
Warning
- Some planters recommend sprinkling salt on the soil to kill tree roots. However, this method will kill all the trees in the area and can pollute groundwater.
- Herbicides can cause damage to the skin and lungs, especially in concentrate form. Follow the first aid instructions listed on the package if you are exposed to the herbicide.
- Removing a large number of roots can uproot the tree in strong winds.
- Herbicides applied to trees can be lost if exposed to rain for six hours in a row.
