Are Magnolia Tree Roots Invasive? [And How To Remove Them]

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Magnolia trees are undoubtedly one of the most stunning and easiest garden plants to care for. They attract birds with their alluring fragrance and add an almost majestic appeal to any landscape. If you are considering growing magnolia trees in your garden, you may have questions surrounding their root systems and how they develop. One common question is whether or not their roots are invasive. In this post, we will answer this question for you and discuss other attributes of the Magnolia plant and its growth.V

The magnolia tree roots do not grow straight down, but instead, grow horizontally to help stabilize the tree. Under normal conditions, their rope-like roots are not known to be particularly invasive. However, they can cause foundational issues under certain conditions. The tree roots prefer to stay closer to the soil, which may cause issues if there are plants that are too close to the walls of a home.

Compared to the roots of similar plants, the magnolia tree is about average concerning its ability to cause foundational or sewer issues. Meaning that the roots aren’t known as troublemakers, but you should consider the location before planting the tree to prevent such issues. Continue reading to learn more about the root systems of the magnolia tree and other useful details.

A Magnolia Soulangeana tree blooming under the summer sun, Are Magnolia Tree Roots Invasive? (And How To Remove Them)

How Magnolia Tree Roots Grow

A blooming magnolia tree with gorgeous pink leaves at a park

Magnolia trees can grow up to 80 feet tall and their root systems can span out up to four times the width of the tree’s branch spread. Because magnolia trees grow horizontally as opposed to vertically, they aren’t known for causing any plumber or sewer issues. However, if the tree grows large enough and close enough to a home it can lead to foundational issues–especially if the roots do not receive enough irrigation.

For example, if the ground is extremely dry for a prolonged period of time, the roots may shrink. In some cases, this may cause the soil to pull away from around a home’s foundation, causing it to crack. Let’s take a look at how to remove the roots of a magnolia tree should you begin to experience issues with them surrounding your home.

How to Remove Magnolia Tree Roots

The most common ways to remove the roots of a tree include cutting them, using an herbicide, or using rock salt. Below we will discuss the steps for each method.

Cutting Magnolia Tree Roots

Things you need:

  • Measuring tape
  • Painter’s tape (or another colored tape)
  • Watering can
  • Chainsaw, sabre saw, or hacksaw.
  • Trash bags

Mark the Roots that are an issue

Take a walk around the entire tree and make a note of which roots are causing the issues. Take your masking tape and place a piece at the top of each root that you plan to cut. If the root is a part of a large group of roots, you may want to contact a landscape expert to determine if it is safe to do so.

Measure the Roots

Wrap your measuring tape and bring it around the entire trunk of the tree to get the diameter. Next, divide the number by 3.14 also known as “pi”. This is an important step because it will allow you to know which roots are safe to prune. As a rule of thumb is best to only cut roots that are at least 10 to 15 inches away from the tree.

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Dig out the Root

Next, after you have all of your roots marked, dig a hole around the first one until it is completely visible.

Cut the Root

Grab your saw and cut the root at the base pulling it as you cut it. Be sure not to pull the root above the area that you have marked. Afterward, place the dirt that you removed back into the hole where the root was dug up.

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Monitor Tree Health

Be sure to monitor the magnolia tree over the next few weeks to ensure that it remains healthy. If you see any signs of stress such as yellow leaves or excessive leaf dropping, it may be best to call an arborist to advise you on how to care for the tree.

Quick tips

  • As a rule of thumb, never cut a root that is more than 2 inches wide. If you remove the largest roots from the magnolia tree it can cause the tree to become unstable within the following weeks and months. The tree will become unhealthy, as it will not have the root system it did to absorb an efficient amount of nutrients and water.
  • Never remove any roots that are fused or within a few inches of the trunk of the magnolia tree, as these are critical to supplying the tree with much-needed nutrients.
  • The best time to cut the roots of the tree is in the early spring and winter before it starts its growth cycle.
  • It’s best not to remove over 15% to 20% of the tree’s surface roots within one pruning session, as it can be challenging for the tree to recover. Instead, wait 2-3 years for your next root pruning session.

Rock Salt Method

If you don’t want to storm the laborious task of cutting the roots, you can also use rock salt to kill the roots. Rock salt dries out roots by stripping them of their water supply.

Things you’ll need:

  • Watering can
  • Rock salt
  • Rubber gloves
  • Electric drill (with multiple drill bit sizes)
  • Trash bags

1. Start by drilling five to seven 3-inch holes into the trunk of the magnolia tree.

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2. Next, grab your rock salt container and pour it into all of the holes that you have drilled. Then pour water on top of the salt to melt the solution. It’s best not to overfill the holes to avoid the solution running off into the grass and poisoning the surrounding landscape. Rock salt is also poisonous to pets and animals.

If you need to hand pour the salt for the smaller holes, be sure to wear rubber gloves as the salt may cause hand irritation, especially if you have open cuts. Repeat the steps until you have filled all of the holes of each of the roots that you want to kill.

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Herbicide Method

An herbicide is definitely the fastest way to get rid of unwanted magnolia tree roots. There are several different herbicides that you can purchase, some offering all-natural solutions.

Things you’ll need:

  • Chainsaw, sabre saw, or hacksaw.
  • Garden sprayer B089GNWPJP
  • Watering can
  • Rubber gloves
  • Herbicide

1. If the magnolia tree has already been cut down and removed, take your saw and cut a 3 to 5-inch slice off of the remaining trunk. Doing so exposes new flesh of the trunk, making it easier for the herbicide to penetrate and quickly get to the roots.

2. Next, take your watering can and pour water on the outer ring of the tree trunk to saturate it. The water will work to carry the herbicide from the tree trunk to the roots.

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3. Mix your herbicide with water (if recommended by product label) and pour it into your garden sprayer. Next, spray the herbicide onto the exposed tree trunk making sure to saturate the top and sides of it. Be careful not to spray the grass or landscaping around the tree, as the herbicide will kill it–as well as any pets are animals that eat the grass. You will notice that the roots will die off in about a week or two after applying the herbicide.

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How Far Away From The House Should You Plant Magnolia Trees?

The ideal distance that a magnolia tree should be planted from a home is around 30 to 60 ft. Planting the tree a considerable distance from the home will help to prevent potential foundational damage as the tree begins to grow. It also helps to prevent the canopy of the tree from blocking the home from the sunlight.

Can A Magnolia Tree Damage House Foundations?

An up close photo of a Magnolia trees blooming flower petals

The roots of a magnolia tree do have the potential to damage the foundation around a home. As the tree grows larger, the roots also grow in size and length and may cause cracks in the foundation. The best thing to do to avoid this is to make sure that the tree is planted at least 30 feet away from the walls of the home.

Can You Dig Up And Replant A Magnolia Tree?

Yes, if you were looking to transplant your magnolia tree, you can definitely dig it up and move it to a new location. Below we have included the tools and steps needed to do so.

Things you’ll need:

  • Garden shovel
  • Watering can
  • Wrapping twine
  • Tarp
  • Mulch or compost

Step One

Water the soil around the magnolia tree thoroughly to help soften it–which makes it easy to dig up. Next, use a piece of twine to wrap around the lower tree branches to protect them. You can also cover them in a plastic bag.

Step Two

Use your shovel to create a trench around the tree trunk that’s about 2 feet in depth. This trench should be within 6 inches of the trunk of the tree. If any surface roots are blocking this area, you will need to cut them with your saw.

Step Three

Take your shovel and place it beneath the tree, and then, using your foot as leverage lift it out of the ground. Gently grab your tree by the base of the trunk and place it aside. If needed, tie up any other loose branches to prevent them from breaking during the process.

Step Four

Next, use your shovel to dig a hole that’s three times wider than the root ball of your tree. Then fill in the hole with any surrounding soil.

Step Five

Carry the magnolia tree to its new location holding it by the ball and the trunk. When you arrive at the new location slightly to the root ball to place it inside the hole.

Step Six

Position the magnolia tree in the hole and the sure that it stands straight and doesn’t lean to the side. Fill the area around the root ball with topsoil or compost as needed. Depending on the size of your root ball, the tree may need anywhere from 3 to 6 inches of compost or mulch.

Step Seven

Water the area around the magnolia tree to ensure that the new roots can immediately replenish their water supply. You’ll also want to make sure that the receives consistent watering for the next several weeks

What Can You Plant Near A Magnolia Tree?

There are several plants that you can place near your magnolia tree, here are a few common ones:

  • Ferns
  • Lenen
  • Rose
  • Vinca
  • Hostas
  • Epimedium
  • Polygonatum
  • Geranium

Wrapping Things Up

Magnolia trees aren’t typically known to cause foundational or root issues when planted near a home. However, it is best to plant trees at least 30 feet away from the home to avoid these types of issues.

Before you go, be sure to check out our other posts:

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What Are Dicot Plants? [Inc. 11 Examples]

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