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Dealing with Trees with Surface Roots

If you have large-growing Trees in your yard, sooner or later you may have to deal with the issue of surface roots.

Surface roots can make it a challenge to maintain a nice level lawn under your shade Trees. Large Tree roots become a tripping hazard and also make it hard to mow under the Tree. They can even cause sidewalks nearby to heave and crack.

What causes surface rooting and what can be done about it?

Getting the answers right here is very important, because a misstep could jeopardize the health of a cherished old Tree. We’ll answer these questions and also tell you what you can do to avoid problems in the future if you’re planting a new Tree now.

What Causes Surface Rooting?

Some kinds of Trees are predisposed to having shallow roots. Trees like Norway Maple, Red Maple, and Silver Maple are some well-known examples, along with Willow, Aspen, Pin Oak, and Beech.

But any large-growing Tree is likely to develop surface roots when it reaches a certain age. That’s just how Trees grow.

surface roots-2

Most Tree roots grow wide and shallow.

Contrary to popular belief, Tree roots usually do not grow very deeply unless the soil they’re in is quite sandy and loose. You might be surprised to know that very few Trees have a taproot and that the majority of Trees’ roots are found in the top 12 inches of soil.

When main roots lying a few inches underground get big enough, they break the surface. Rain and wind may then erode the soil, leaving the roots even more exposed.

Roots are shallower in poor soils.

Surface rooting is most common in compacted soils like that found in many urban and suburban lots and even in the country where soils have lots of heavy clay in them.

Roots need to breathe.

Roots need oxygen, and in tight soils they grow more shallowly to reach the oxygen they need to survive. Surface roots are the result of Trees adapting to their environment and making the best of a less-than-ideal situation.

What Can I Do about Surface Roots in My Lawn?

If you have a big Tree in your lawn and surface roots are a problem, there are a couple of things you can do.

Don’t cut big roots.

The thing you should NOT do is to cut the offending roots. Cutting large roots can give diseases and insect pests an easy entry point. It can also make the Tree less stable and more likely to blow over in a storm. Not to mention that cutting one big root can kill thousands of tiny “feeder roots” attached to it that allow the Tree to take up water and nutrients. Cut too many roots and you’ll have dieback in the canopy or possibly the death of your Tree.

Consult a qualified arborist if you think cutting roots is the only viable option.

Topdress with a light soil mix and seed.

A better plan for dealing with surface roots in lawn is to put down 2 inches of a 50-50 mix of topsoil and compost around the Tree and sow the area in late summer with shade-tolerant grass seed, keeping it well watered. If the roots are still too prominent a year later, you can add another 2 inches of the soil mix and reseed, but never add more than 4 inches of soil to the area beneath an existing Tree.

Remember that roots have to breathe, and it is possible to suffocate a Tree by changing the grade too much.

Instead of grass, you could plant a drought-tolerant groundcover under the Tree which would save you the trouble of having to mow in that area—or, mimic nature and consider using moss as a groundcover!

Mulch is the best solution.

The best plan, however, is to put down 4 inches of organic mulch—preferably wood chips—around the Tree.

Wood chips will help to level out the area while keeping roots cool and moist and allowing oxygen into the root zone. Don’t put down more than 4 inches, though, and be careful not to pile mulch against the trunk. Pull it away so that it doesn’t hold moisture against the trunk and encourage disease or give critters a place to hide while they nibble the bark.

How Can I Prevent My New Tree from Having Surface Rooting Problems in the Future?

When choosing a Tree, avoid notorious surface-rooters.

If you have clay or compacted soil, your Tree will probably have some surface roots eventually, but some Trees are worse offenders than others. If surface roots will pose a problem in your planting area, steer clear of the following:

Shallow-Rooted Trees
Aspen
Beech
Birch, River
Maple, Freeman (like Autumn Blaze®)
Maple, Norway
Maple, Red
Maple, Silver
Maple, Sugar
Oak, Pin
Spruce
Sweetgum
Tulip Poplar
Willow

Choose a Tree with a relatively deep root system.

Given enough time and an average to heavy soil, just about any large Tree will have surface roots. However, these choices usually pose less of a problem:

“Deep-Rooted” Trees
Black Gum
Cedar, Blue Atlas
Ginkgo
Golden Rain Tree
Horsechestnut
Oak, Red
Oak, Regal Prince®
Oak, Swamp White
Oak, White
Oak, Willow
Planetree
Yellowwood
Zelkova

Will a smaller Tree work for you?

Trees that mature at under 30 feet tall will usually not have roots large enough to cause major problems. Maybe one of these smaller Trees could do the job:

Small Trees
Cherry
Crapemyrtle
Dogwood
Fringe Tree
Golden Chain Tree
Hawthorn
Hornbeam, American
Lilac, Tree
Magnolia, most
Maple, Japanese
Maple, Paperbark
Mimosa
Mountain Ash
Purple Leaf Plum
Redbud
Seven Son Flower
Silverbell
Snowbell
Stewartia

Plant your Tree at the right depth.

Don’t plant your new Tree too deep, thinking that it can just grow deeper roots from the start! Young Trees need to breathe just like older ones do, so plant your Tree at the same level it is growing in the pot or even a bit higher—Bower & Branch™ recommends planting 2 inches above grade.

Don’t plant the rootball higher than 2 inches above the ground, though. If your Tree sits too high, its roots may dry out, and it may also be more vulnerable to freeze damage in the winter.

Give it room to grow.

Give your Tree space if there is pavement nearby. Large-growing Trees should be planted 6 feet away from paved surfaces if possible.

You may want to use your Tree as a street Tree and plant it in the Tree lawn between the sidewalk and the street. In this case, only plant a large Tree if you have a generous Tree lawn that’s 8 feet wide or more and have no utility lines overhead. If the planting area is less than 8 feet wide, choose a medium or small Tree that won’t outgrow its space.

Some cities have restrictions on which Trees can be planted in right-of-ways. If you’re a city dweller, check with your local urban forestry department for specific guidelines on planting street Trees and a list of suggested Trees for your area.

Choose mulch instead of turf.

Make a decision early on to surround your Tree with mulch instead of trying to grow grass right up to the trunk. Grass invites foot traffic, which leads to compaction, which depletes soil oxygen, sending roots to the surface, gasping for air. (Well, maybe it’s not that dramatic, but you get the picture.)

In short, keep your Tree breathing easy and you’ll breathe easier, too… under the shade of a magnificent, healthy old companion!

8 Comments

  • Debra says:

    If the exposed surface routes are starting to hollow out is that a sign that the tree is dying and needs cut down? I’m always worried when we have heavy winds that the tree is going to fall on our house. It is a silver maple. I don’t want to remove it but will if there is a high likelihood it will fall down

  • Wendi-Jo says:

    Hi Debra!

    Silver Maples are famous for exposed roots and while they can be long lived Trees, they are also notorious for wind damage and weakening structure over time. With that being said, we understand the desire not to give up on your Tree.

    If you are able, please send some photos to us and we will share with our Growers. Or, if you prefer, we can have one of our Growers talk you through what might be best for your Tree. Many times, for a mature Silver Maple, a strong pruning could be beneficial and extend the useful life of the Tree. We do not believe the issue with the roots you are seeing is an indication of failure.

    A professional pruning will reduce chance of wind damage. Another consideration may be to plant a replacement Tree(s) nearby and begin to plan for the eventual replacement that will be required. Again, any photos you can send of your property will allow us to guide you on this.

    Thank you for your question and we look forward to encouraging you through this Tree challenge!

  • Corinne says:

    September 2017

    Hi, we planted a silver maple tree about 15 years ago in our backyard. We planted it too close to our house, not realizing how quickly it would grow. The closest point to our house is 13 1/2 feet. We are concerned that the roots will do damage to our foundation, etc. We are not on a septic system. We have noticed that the majority of the surface roots, which are getting quite big, are growing on the back side of the tree, away from the house where there is more room to grow. Large tree roots are not visible above ground in the direction of our house. Should we consider cutting the tree before it damages our foundation? I love this tree and hate the thought of cutting it down but will if it is likely to do damage. Thanks for your reply.

  • Wendi-Jo says:

    Hi Corinne,

    Thank you for reaching out!

    I’m afraid, in this case, you are worried about the wrong end of the Tree!

    Roots will grow until they reach a barrier, they will then reroute. They won’t grow into your foundation unless there is a crack into which they can grow.

    The problem here is that Silver Maples have what we call ‘weak wood’. At this age, it may not be something you really have to worry about but within ten years, you should. Your Tree will begin to drop branches or if a strong storm comes through, it will cause them to fall.

    The question you need to ask yourself is – do you want to wait for something to happen in ten years or be ahead of the game?

    If you choose to remove the Tree, you should consider the Autumn Blaze Maple as a replacement. This one in particular is a hybrid – its ‘mom’ is the Red Maple and its ‘dad’ is the Silver Maple. It has the vigor and growth rate from the Silver Maple but not the issues with weak wood. It truly is a fantastic Tree!

    Let us know if you have any other questions! Our Growers are available to help you out in any way possible!

    Thank you & enjoy your day!

  • Debra Silver says:

    I am getting a hole in the center of my crapemyrtle tree where the branches start. I don’t want it to rot or get insects/critters there. What should I do. My tree is 40 plus years old. I love this tree….help (Southern Belle from NC)!!

  • Wendi-Jo says:

    Hi Debra!

    Thank you for contacting Bower & Branch!

    We understand your love for Crape Myrtles and in your neck of the woods, I would imagine they are spectacular!

    I’m afraid I may not have to most encouraging news for you. Crape Myrtles are not considered to be a multi-generational Tree – your Tree is entering its ‘Golden Years’.

    We don’t believe any treatment or ‘surgery’ could prevent the inevitable at this point. If you are able to maintain optimal conditions (supplemental watering, fresh mulch bed, etc.), you may be able to enjoy your Crape Myrtle for another ten years or so.

    I am very sorry we don’t have a better diagnoses for you. If you have any other questions, feel free to email us at customercare@bowerandbranch.com, Live Chat with us on our site or call us at 866-873-3888.

    Thank you & enjoy your day!

  • Penelope says:

    We have a very large Zelkova tree approximately 15 feet from our house. It’s likely 80 feet tall and 60 years old. We found one root growing along the length of the foundation (~1.5 foot deep). That root was about the size of an adult wrist. We cut that root because we think it is the reason a foundation crack has started leaking. The soil here is clay. I’m trying to figure out if I should dig all the way down to the bottom of the foundation to look for more roots. Would it be reasonable to expect there to be deeper roots of similar or larger size also growing in the same area?

  • Wendi-Jo says:

    Hello Penelope!

    Great question!

    Tree roots actually grow out (not down), only a foot or two below the surface, so the chance of there being large roots at the base of your foundation is very low.

    Now, you may have done damage to the Tree when you cut the root. You won’t see the resulting damage until next year, as the temperatures rise and the Tree begins to ‘stress’. We recommend that you supplement with water as we go into Summer to make sure your Tree has plenty in order to push through the shock from the cut. You may see some die back in the canopy as a result.

    We would also suggest that you not cut any more roots unless a Certified Arborist has determined it must be done. You could possibly kill your Tree by cutting the roots or weaken the stability of it, making it more susceptible to blowing over in a storm.

    If you have any other questions, feel free to email us at grower@bowerandbranch.com – our staff of Growers are here to answer any questions you may have!

    Thank you & enjoy your day!

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