Tree Surface Roots: Questions and Answers
Got surface roots? If you have large-growing trees in your yard, you might find yourself having to deal with surface roots. Here are some reasons why surface roots can be problematic:
- They Make Lawn Maintenance a Challenge
- They’re Trip Hazards for Kids in the Yard
- They Disrupt Sidewalks and Walkways
- They’re just unsightly!
So, how do you deal with surface roots without jeopardizing the health of your tree? What actually causes them? We'll answer these questions and more!
What Causes Tree Roots to Come to the Surface?
The truth is that any large tree can develop surface roots after a certain age. As the tree grows in height and the root system expands the tree continues to adapt to take in as much water as possible. Still, besides size and predisposition other factors play a part in the development of surface roots.
The facts are certain, some trees are predisposed to having shallow roots. A few common tree species with shallow roots include:
- Norway Maples
- Red Maples
- Silver Maples
- Pin Oaks
Poor Soil Quality Causes Surface Roots
For the most part, the majority of trees' roots are found within the top 12 inches of soil. Contrary to popular belief, tree roots usually do not grow very deep unless they are in loose and sandy soil. Surface rooting is most common in compacted or clay-based soil often found in urban areas.
When the roots within the first few inches of soil get large enough, they break through the surface. Gradually, rain and wind erode the soil around them, further exposing them.
Lack Of Oxygen Causes Surface Roots
Roots need oxygen. In compacted soil, they must grow up to the surface in order to get enough oxygen to keep the tree alive. In many cases, trees with surface roots are struggling to breathe and are doing their best to adapt to an environment that is less than ideal.
How to Deal with Surface Tree Roots
If you already have a tree or trees with surface roots, there are a couple of things you can do. To start, it’s important to acknowledge that surface rooting isn’t necessarily unhealthy. It’s a symptom of a tree doing what it needs to survive more than a sign that a tree is on death’s door.
Can You Cut Surface Tree Roots?
Don't cut the offending roots, no matter how tempting it is. Cutting them can provide an easy entry point for diseases and harmful insects. It can also negatively impact a tree's stability, making it more likely to fall over in a bad storm. Finally, cutting roots can kill thousands of tiny "feeder roots" that allow the tree to absorb water and nutrients. This can lead to dieback in the canopy or complete death of the tree.
There are much better solutions to surface roots than killing the whole tree!
Topdress Around The Base Of The Tree To Deal With Surface Roots
One of the most common solutions to surface roots is to topdress the base of the tree.
Here’s how we recommend to do so step-by-step:
- Mix equal parts topsoil and compost.
- Apply two inches of the mixture around the base of the tree.
- Sow the area in late summer with shade-tolerant grass seed, keep well-watered.
- If the roots are still prominent within a year, you can add another two inches of the mixture and reseed.
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Use Mulch Over Your Trees Surface Roots
You can also put down four inches of mulch—preferably wood chips—underneath the tree. This will help level out the area while keeping roots cool and moist and allowing them to breathe.
Don't put down more than four inches, though, and don't pile mulch against the trunk. Remember, the reason the tree roots are surfacing is because they need more oxygen. Burying them again won’t help!
How to Prevent Tree Roots from Surfacing
If you don’t already have surface roots, there are a few things you can do to ensure that you don’t run into this issue in the future. Many of the tips below are reflective of fundamentally good planning and planting practices when it comes to your backyard or garden.
Avoid Planting Trees With Shallow Root Systems
If you have compact or clay soil, your tree will inevitably have some surface roots. Still, some trees are way more likely to develop them than others. These trees have inherently more shallow roots and are more likely to pose a problem in your landscape.
Notorious Surface Root Trees:
- River Birches
- Certain Maples (Red, Silver, Sugar, Freeman, and Norway)
- Pin Oaks
- Tulip Poplars
- Weeping Willows
Choose Trees With Deeper Root Systems
Some trees have deeper root systems. These trees will make much better options in your landscape and are much less likely to develop surface roots. You will need to double check and make sure you’re not in danger of impacting any buried utility lines on your property or neighbor’s property. Remember, plants don’t observe or respect property lines!
Common deep root system trees include:
- Black Gum
- Blue Atlas Cedar
- American Sweetgum
- Fort McNair Horsechestnut
- Oak Varieties like Red Oak, White Oak, and Willow Oak
Consider A Smaller Tree
Trees that mature at under 30 feet tall will usually not have roots large enough to cause major problems. Naturally, smaller trees will have less shedding on the lawn as well. Many homeowners with concerns about tree size opt for a smaller specimen tree that they can then build a garden around.
If you think a smaller tree might be a better option for your yard, consider varieties like Flowering Cherry Trees, Dogwoods, Magnolias, or Japanese Maples, just to name a few.
Don't Plant Your Tree Too Deep
Planting your tree deep within the soil won't actually prevent surface roots. We actually recommend planting trees two inches above grade. The most important factor to consider when planting is ensuring the root ball isn't exposed. An exposed tree root ball could dry out and be more vulnerable to winter damage.
Give Trees Room to Grow
Give your tree space if there is pavement nearby. A large tree should be planted at least six feet away from paved surfaces. If you want to plant your tree between a sidewalk and a street, make sure the planting spot is at least eight feet wide with no utility lines overhead. Otherwise, choose a smaller variety.
Keep in mind: some cities have restrictions and specific guidelines on planting, so you'll want to check with your local forestry department before planting.
The Truth About Tree Surface Roots
The facts are that in the majority of cases tree surface roots are a presentation or aesthetic issue more than a genuine emergency. We have to stress again that you cannot remove surface roots without causing significant harm or even death to the tree. Plant with intention to avoid this issue, but if it has already developed: topdress the base of your tree with native grasses or mulch.
In the long run, your tree will be healthier and thrive longer for many more years of enjoyment.
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