Last Updated on June 11, 2022 by Gary Stephen
Trees are a marvelous addition to any garden. They offer shade for you (and some of your plants). And it becomes a perfect place to read a book, for some tables and chairs to have a coffee in the morning. Besides, it can turn an otherwise simple garden into something truly grand. But when tree roots become exposed, they can be both unsightly and a big problem
Tree roots can become exposed for a few reasons. Whether it’s because it was planted in the wrong soil, or simply because of some basic soil erosion, they can be a serious problem in your garden.
They twist and churn up the ground, turning the roots into a tripping hazard, a danger for your lawnmower, and even a potential problem to your house. Some roots can make a wall collapse! Outright chopping or cutting up tree roots isn’t always the answer either, as removing too much can actually damage and even outright kill a tree! Removing more than 20% of a tree’s roots will kill it, so don’t just go at it with a hacksaw. Your tree still needs them to survive, to help you do the best for your tree, we’ll look at how to cover those roots and two ways you should never do it!
Why do tree roots become exposed?
There can be any number of reasons why they become exposed, but it all has to do with the soil.
Trees are reliant on the correct soil. If the soil is the wrong type, the tree will begin to adapt to survive in its environment.
- Compacted soil – soil that has become too compacted from foot traffic, motor traffic, or other reason offers no space for a tree’s root system to grow. It begins to push up to find what it needs. when the roots begin to grow outward from the tree, it dislodges the clay and becomes visible. Some basic rain erosion and the roots will be completely exposed in a very short time.
- Lack of oxygen in the soil – Despite having about 70% of your tree above ground, it still relies on the roots to suck up oxygen. If the soil is too thick or lacks the oxygen level your tree requires, the roots will begin to push up to absorb oxygen that way.
- Erosion – the final problem is erosion, whether through rains, wind, or the soil is too loose, soil erosion can quickly expose your tree roots.
How do tree roots work?
Before we think up ways to deal with our wayward friends, we first need to understand how tree roots work so that we don’t end up making life even more difficult for ourselves (and them!).
Tree roots serve a few functions, mainly to gather nutrients and oxygen in the soil – a tree’s roots need to breathe. Without the proper soil, it simply cannot do so and will begin to suffocate, which will push it up towards the surface in desperate need of air. This is why it is so important to plant it in the correct soil type, and not to cover the roots up with any old things. The second main function of roots is to stabilize the tree against the elements, like winds or floods.
Overall, the largest part of the root system will be just below the surface at around 12 inches. This means that roots can easily become exposed via natural erosion, or when it needs oxygen.
Exposed roots are part of the woody roots, which make up a huge chunk of the tree root system. Averaging between 50-90 percent, depending on the species. These roots are used as a sort of storage space for sugar and starch to keep the tree going. They also absorb other minerals, but overall water and minerals are left to the fine feeder roots, which usually do not grow on the surface.
So, what does this mean for a gardener?
Always remember that your root system needs oxygen, and covering it in grass or plants or more dirt will only make its life more difficult.
Don’t cut off the exposed root system! Although it is a pain to manage, unless you’re planning on uprooting the tree and planting a new one, cutting the root system will most likely kill your tree. But the most important thing to remember when dealing with roots is the root flare, or primary root should be exposed at all times. This is the root that is connected to the base of the tree. You can cover the exposed roots that are at ground level but do not cover the root flare.
But now that you understand the inner workings of your tree’s roots, let’s dive into how you can safely manage your surface roots, without causing undue stress to the tree.
Do: Put mulch around the tree
Let’s start with what you should, and a very effective technique; mulch.
Made up of pine needles, woodchips, or old leaves, bark, and other organic materials, mulch is a quick and easy way to cover exposed roots and prevent your children from tripping over them. You can use around 2-3 inches of mulch to safely cover the roots. But less is better.
Simply fill in the spaces between the roots with good soil and pour the mulch over the exposed roots until they are covered. Do not stamp or flatten the mulch, remember we want the tree to keep breathing!
Some people like to make what as a ‘mulch volcano’ you will often spot them, they look like mounds under the tree, and the tree looks like it is sprouting up from a mountain. This is the worst thing to do to a tree, as it suffocates the root system. If you have a mulch volcano, go and open the mulch and see what is going on inside.
Chances are good you’re going to find a secondary root system trying to grow up and out of the volcano, these tiny roots are usually under the tree, but because the primary root system can’t find oxygen, the secondary root system jumps into action to try and save the tree.
You don’t need more than around 2 inches of mulch and always keep it loose on the tree.
Don’t Do when Facing Exposed Tree Roots
Grow grass around the tree
A fix a lot of people might consider is to grow grass over the tree roots on a new layer of soil. It might look pretty, but it won’t help.
As we stated above a tree needs oxygen to breathe, and when it is completely covered in new soil, it won’t be able to get the amount of oxygen it needs to survive. To compensate for this, the tree will begin to push out a secondary root system to make up for the lack of air. This root system will push up towards the new soil and grass, in turn tangling with the grassroots and killing your new grass!
This same argument will go with any plant you think will look good around the tree roots. Remember your tree is looking for oxygen, covering up its root will only make it more desperate and that secondary root system will kick in.
Although it might look better, it’s not a solution for exposed tree roots. Rather pick up that mulch and start pouring it over.
Chop off exposed tree roots
Earlier in the article, we discussed how chopping off tree roots can kill a tree. And this is very true. A tree is dependent on its roots, if you chop it off, we take away its arteries, it’s very means of gathering any sort of water and minerals to survive.
However, there are exceptions to this.
If a tree’s roots are starting to damage your house, or it’s in a very inconvenient spot, then you might have to think about cutting off the root. It’s best not to do it yourself and call in a professional tree surgeon who will know how much you can cut off and where.
Your tree’s life is on the line, and if you want to keep it in your garden, rather treat it well and bring in someone who knows what they are doing.
Quick tips for planting trees
If you’re planning on planting a tree in your garden, and you want to avoid the possibility of exposed roots, then here are a few quick tips you can keep in mind.
- Make sure you have the correct soil type. Each tree grows differently and has different needs. Make sure when you pick a tree that it is compatible with the soil in your garden, otherwise, you’ll have problems.
- Don’t plant it too shallow, but also, don’t plant it too deeply – When planting a tree, you need to make sure it is deep enough to ensure its roots will spread out well, at the same time you want to plant it shallow enough that they still get all the oxygen they need. Speak to the botanist at the nursery and make sure you understand how to plant your tree.
- Give it some space! – one of the deciding factors on whether a tree will be in trouble in a few years is where you plant it. Planting right next to the house won’t bode well, nor should you plant it right next to another tree. A tree’s root system is oftentimes wider than the foliage, so make sure it has enough room to spread its legs, otherwise, you’ll have a very unhappy tree.
Although we love our trees, we’re not too fond of them when they become a hassle or even a hazard. Their root system can cause some serious damage to your homes, and they can be a danger for your kids. But despite how annoying they are, they still make up part of your tree, and it is best to remember that when dealing with it.
Sawing off the roots isn’t the answer, and covering it up with a layer of grass will only exacerbate the problem. Use simpler methods to help your tree. It might not look as pretty as a new patch of grass, but it will keep your tree hearty and healthy, and really at the end of the day that is all we want.