Mowing Under Trees And Around Roots

It can be tricky maintaining a neat and tidy garden, especially if you have trees growing in the middle of your lawn. Trying to mow around trees can make the job more challenging, but it is important to cut grass under trees the right way. 

When mowing under trees you have to avoid both the tree trunk and any exposed roots in your lawn.  You may be able to use a mower, but for narrow areas you may be better off with a grass trimmer or hand clippers. First, pick up any debris under the tree. Then cut grass carefully making sure you do not hit the tree or roots at all.

If you don’t it could cause you more headaches than the original long grass underneath the tree. Let us guide you in your mowing adventure, and give you a few tips on how to reduce the problem.

We’ve covered everything you need to know, read on!

How do you mow around tree roots?

The main thing is that you don’t want to get close enough to the tree or exposed roots that you touch them with the mower. (That way, both your tree and your mower are safe from damage).

Whatever you do, don’t just mow over the roots. This causes damage both to the tree and to your lawnmower.  We will now go through specific strategies on how to mow under trees and while protecting the tree and its roots.

Imagine an area around the base of the tree of about 1-1.5 meters (3-5 feet) that you don’t cross. As you reach this imaginary boundary, slow down and take more care.  

You can do the same thing for any exposed roots growing in the middle of your yard, away from the tree’s base. In this case, a one-meter perimeter should be ok.

Pick up Sticks before Mowing!

The first thing you need to do is pick up all sticks and seed pods from underneath the tree. 

Trees are excellent for providing shade, creating a relaxing environment, and encouraging birdlife into your yard. They also drop sticks, leaves and seedpods (depending on the species). You’ll want to pick these up off the lawn before mowing, (especially the larger ones) as they can damage your mower if it runs over them.  

The dropped branches and seedpods can also be flicked back at your legs and feet at high speed by the mower blades, (and you’ll certainly know about it when it does!), with injuries ranging from a bruise to a cut. It can be easy enough to pick the larger items up by hand, but you may want to use a rake to catch the smaller debris.  

Be aware of any low hanging branches too. It’s up to you whether you want to trim them first, or duck underneath them as you mow… just don’t get caught on them!

Cutting grass under a tree with a lawnmower

If exposed tree roots are not raised too far above the lawn surface and you have an adjustable height mower, the easiest thing is to raise the height of your mower. But you need to be careful here, and really make sure the lawnmower will clear the roots. 

If you have an adjustable height mower, then when you get close to the tree you can raise the height of your lawn mower. For bigger spaces, you can also get a zero-turn mower to make the job more manageable, as it has greater manoeuvrability in tight corners. 

Using a string trimmer grass around a tree

When trying to cut grass around obstacles and in pokey little areas many people reach for a string trimmer. You might know this as a whipper snipper!

But you really need to proceed with caution and go slow. The nylon cord is able to cut the bark and damage the tree so really you don’t want to go too close. Just use your string trimmer to get ‘close enough’ to the tree trunk,  or use it to access the areas in between surface tree roots leaving some long grass closest to the bark.

I need to emphasise how important it is not to get too close to the tree with a whipper snipper. If you go around the trunk and hit the bark, you are likely to end up ring barking the tree. The bark is the passageway for all nutrients to get from the roots to the top of the tree. If you cut the bark all the way around the tree, then you can say goodbye to your tree, as it will die. 

Finish off the job with Hand Shears

If you do need to trim grass right up to the base of the trees, or over exposed roots, use a pair of hand shears. It’s handy to have an outdoor pillow you can kneel on while doing this, it’ll save your knees.

Does mowing over the roots really damage the tree? 

Damage to surface roots by the mower are not just superficial damage. It weakens the tree’s defence against the elements, making it vulnerable to disease and pests. Just like us, open wounds are not something you want for a healthy tree. 

Many people are not aware that injury and infection started by lawnmower wounds can often be the most serious threat to tree health. Although large wounds are most serious, repeated small wounds can also add up to trouble.

Tree bark isn’t just a protective outer layer of the tree (like our skin), it’s also an essential part of the tree’s delivery system: transporting vital nutrients. Depending on how severe the wound is, it can reduce or cut off the flow of water and nourishment that’s fed into the tree by the roots

You could also think of roots as a kind of anchor; trees are heavy, especially as they get bigger. Roots are the support system that keeps the tree in the ground and standing upright. Damage to the roots, when significant enough, or on a critical root, will affect the tree’s stability. This could eventually lead to it falling (and it could happen when you least expect it).

Tree Root Damage From Mowers Can Sometimes Produce Suckers

Another reason for you to make sure you avoid  hitting the roots with your mower trimmer,  is that with some tree species, damage creates sucker roots.

This is where more roots grow from the injured area causing saplings to spring up all over the place!

Can mowing over roots hurt your mower?

Even if you don’t have a great fondness for your tree,  you may want to think about your lawnmower.  hitting hard obstacles like rocks, roots and old stumps can damage the mower’s blades, spindle, shaft and transmission.  The worst case scenario is that the lawnmower damage could even compromise the safety of your lawn mower. As damaged equipment could lead to breakage during use. The last thing you want is a blade flying off towards your legs!

Adapt your landscape to deal with trees and their roots 

Trees can make beautiful features in your yard, but they also require care to keep them healthy and strong. Don’t mow over their roots, but instead, find a way to protect them.

A good thing to consider is instead of dealing with a problem why not work with what you’ve got and change your landscape plan. You don’t want to mow over the roots, but you also probably don’t want them surrounded by long, untidy grass. What a dilemma!

avoid mowing near roots

Who knows, maybe you’ll come up with a creative solution and a gorgeous addition to your garden? 

Create Mulch Rings So You Don’t have to Mow So Close

The simplest ideas is to think about creating mulch rings around your trees so you don’t need to worry about cutting too close to the trunk? They look great, keep weeds in check, and also reduce the trees competition for water! 

Can I Cover Exposed Tree Roots With Dirt?

Exposed tree roots can be covered if you are careful. The roots need access to oxygen, so the last thing that you want to do is pour a heavy load of dirt on top of them. If you do want to cover them, your best choice is to use a course material like shredded wood, woodchips or riverstones. 

A mulched area doesn’t need mowing and will discourage foot traffic. It also cushions and insulates the roots; protecting them from the elements (and people), but also a light enough covering to allow the air, water and nutrients to reach the root.  

Don’t get too carried away and pile the mulch right up around the base of the tree though! Creating a ‘mini-volcano’ can trap excess moisture and result in rotting. It’s best to keep the mulch an even 7.5 to 10 centimetres deep (3-4 inches). 

Start from about 2.5 centimetres (1 inch) away from the tree trunk, and spread it across an area that is large enough to cover all areas of exposed roots.

Remove The Lawn So There Is No Problem!

Instead of looking at the roots as a problem, look at it as a creative challenge: an opportunity to do something unique with your garden.

Where your lawn has got exposed tree roots, you might want to consider removing the lawn carefully and extending your garden bed. If you  add a lovely variety of native grasses, these will hide the roots while also reducing ongoing maintenance. Just be careful, as digging deep holes for plants can also harm roots. For minimal upset, just use small seedlings.

You could cover the area with decorative gravel and river stones, and then add a collection of ornamental pot plants on top of the stones to make a unique garden. (You could send a trend, and inspire your friends and neighbours!)

A Deck Over the Tree Roots So You Don’t Need To Mow!

Depending on where the tree is located, you could look at is building a deck around the tree. It doesn’t need to be a full-sized entertainment area; it can make a delightful little stand-alone feature. Add some outdoor cushions, and you have a lovely shady place to recline in the backyard.

You just need to have the deck elevated enough that it doesn’t touch the roots and that there’s space around the trunk for it to continue to grow in size. This can also benefit the tree; the soil will have less erosion and compaction, and the roots are protected. Just make sure you leave small gaps between the planks to allow water, air and leaves to slip through and continue to nourish the tree.

What if you don’t have the time or energy to spare to rework the landscape of your garden? 

Can you just cut the roots?

Can You Just Cut Tree Roots Off So You Can Mow?

‘If only the tree roots weren’t there, then I wouldn’t have a problem!’ It can understandably be frustrating, but the most likely outcome for trying to cut roots above ground is that you’ll do permanent harm to the tree. You could potentially even kill it, or cause it to one day topple.

If you are decided on cutting the roots out of your yard, the best option is to contact an arborist. They have the best chance of removing the roots, if possible, without killing the tree.

Don’t remove any roots close to the tree trunk, or greater than 5 centimetres (2 inches) in diameter; they are critical to its structure, stability, and a vital part of the nutrient pathways.

Remember that roots supply water to the rest of the tree, so to reduce the risk of dehydration, it’s best to remove them in winter or early spring. (Don’t leave it thirsty in the summer sun)

Roots are vital to the health and stability of the tree. If your tree has a mass of exposed roots, don’t remove more than 20% at once. After the first lot of pruning, wait a year or two to give the tree time to recover before considering more pruning.

FAQs

Are exposed tree roots bad?

Exposed tree roots are not necessarily detrimental to the health of your tree. They can create landscaping and landscape maintenance issues. This can put the tree at higher risk of being damaged by lawnmowers, foot traffic or the elements.

Are exposed tree roots a problem? 

Your tree is probably healthy and exposed roots are more of a problem for you than the tree. Exposed roots can cause damage to landscape plans as they can break through lawns, pavers and concrete. Depending on the tree species, exposed roots can be a sign that the tree is struggling to get enough oxygen.

Why are tree roots exposed?

There are many reasons why tree roots can become exposed. Naturally some roots are closer to the surface and as they grow larger they become more visible. Poor soil conditions like compacted clay can cause shallow roots as trees need access to oxygen. Erosion from rain, runoff, wind and foot traffic can bring roots to the surface.

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