The inviting shade of a tree might inspire you to consider using it’s natural canopy as a roof for a cool backyard patio, or shaded activity area. However, you need to be careful not to pour concrete to close to the base of the tree.
Pouring concrete all around a tree will result in killing a tree by cutting off it’s water and oxygen supply and damaging the roots.
However, you can pour concrete near the tree, as long as you make sure to give the tree enough space around it to keep the roots intact and not disrupt it’s ability to get the nutrients it needs.
Determining How Much Space A Tree Needs
Before beginning the prep work to pour your cement, mark out how much space your tree and its roots will need to remain clear of cement.
To figure out how much space you need, there are a few things to take into consideration:
- Potential size of the tree
- Expanse of the tree’s root system
- Proximity of the tree’s roots to the surface
- Tree watering method
- Future plans for the tree
By doing a little research, you can ensure that your tree won’t be negatively impacted by the addition of concrete to your landscaping.
Potential Size of a Tree
It is important to know the approximate age of your tree.
Knowing how old the tree is can help you determine what the full height and width will be when it reaches maturity.
Knowing this will make it easier to determine how much space the tree will eventually need.
If the tree is young, placing cement around it now without taking into consideration that the roots will continue to expand can place the tree in danger of dying later on.
If you are unsure of the age of the tree, look up the tree and jot down how wide the tree is expected to be at maturity.
However, if you aren’t quite sure what species of tree you have, check out the Arbor Day Foundation tree identification tool or take a picture of the tree in question and show it to your local nursery expert.
Use the adult tree measurements when deciding how much space to give your tree.
Expanse of the Tree Root’s System
The reason for needing to know the dimensions of the fully grown tree is to help determine how large of a radius around the tree you will need to account for the root system.
Although they may seem unrelated, a tree’s root system radius reflects the width of the tree.
In other words, the roots expands as far under the soil as much as it expands above ground.
Take for instance the common maple tree.
According to the University of Michigan Extension, a Red Maple tree has a width of 15-75 feet.
With measurements like this, always account for the larger measurement to make sure you don’t underestimate how wide the tree will eventually grow.
Determining the Radius
To determine how far from the tree you need to go before you pour cement:
- Take the width measurement of tree.
- Divide that number in half (Radius is the measurement of the middle point of the circle to the outer edge of the circle, so 2 radiuses together will give you the width of the circle, not accounting for the width of the tree trunk).
To mark the circumference of the root system, measure out a rope the size of the radius with extra to tie loosely around the base of the tree.
Grabbing on the other end of the rope, walk out to the length of the rope and mark the outer edge of the circumfrance.
To mark the circle, use a bright color marking spray paint.
If the rope will allow you, walk around, holding onto the rope and continue marking a circle around the circumference of the root zone.
Proximity of the Tree’s Roots to the Surface
What if you are not planning on pouring cement completely around the the radius of the tree, but maybe just a sidewalk that runs near one, will that affect the tree?
Walking down a quite neighborhood sidewalk lined with trees affirms that yes, you can have sidewalk near trees, even if it is over the root system as long as it doesn’t cut the tree off entirely to its food supply.
However, you may have also noticed as you walk down that same sidewalk that there are areas where the concrete is lifted in certain spots by the roots of the neighboring tree.
Once upon a time when I was younger and somewhat better coordinated, I would roller blade in my grandparent’s neighborhood in Salt Lake City.
I have vivid memories of my hands and knees making unwanted contact with the rough cement as I tripped over the raised sections of sidewalk.
Although I completely admit that I am not the most coordinated person in the world, my clumsiness was amplified by all of the raised sidewalk by the tree roots.
When planning on how far from the tree you plan on pouring your sidewalk, make sure it isn’t somewhere where the roots are close to the surface.
Not only is it because the roots may lift up the sidewalk when finished, but digging into ground and damaging them can cause that section of root to die, causing the tree to become slightly unstable on that side.
Tree Watering Method
When pouring cement, make sure that the tree’s original water supply is not cut off.
If the tree relies on a sprinkling system, make sure that the water can still reach the roots of the tree.
Also make sure to avoid any pipes or watering system that may need to be reached in case something ruptures or breaks.
If water doesn’t completely reach the tree, you may need to install a form of drip irrigation system or use a hose to flood irrigate the trees as needed.
Future Plans for the Tree
That fact is compounded by the fact that removing a tree can sometimes result in destroying any nearby concrete in order to get to the roots of the tree.
If you are unsure if you want your tree to be part of the permanent landscape of the yard, make sure to give yourself enough space to remove the tree without damaging your concrete work.
Do Tree Roots Crack Cement?
Although trees may seem to be the culprit of sidewalk cracks, they actually are just taking advantage of the weathering of cement.
There are several things that can crack cement such as heavy vehicles that they structurally can’t support, the expansion and contraction of water in the form of ice, and the daily wear and tare that it has to endure.
The tree’s roots naturally gravitate or grow towards water source.
If water is penetrating through a crack, the trees roots will seek out that water.
However, the roots may try to grow through the crack, making it bigger.
Using Pavers Instead of Concrete
If you would still like to have a small little patio underneath your favorite shade tree, there is another option.
Pavers can be used under a tree as long as there is enough space between them to allow the water and nutrients to make their way to the roots.
By simply placing them on the ground, there is no risk to damaging the roots by digging, making it an ideal solution for having a nice hard surface in the shade.
The are also removable, so if you notice something wrong with the tree, they can be removed to allow for extra needed fertilizing and care.
Keeping Your Tree Happy
Concrete is a great element to add to the beauty and function of your yard when applied correctly.
By making sure you keep the tree’s root system in mind, you can combine the beauty and shade of your favorite trees with the solid stability of concrete.