5 Ways Oak Trees Cause Damage (and How to Prevent Them)
The mighty oak tree is one of the most well-known and sought-after trees for the yard. They provide shade for backyard barbecues, shelter, and food for woodland critters, and some turn beautiful colors in the fall. But what about the downsides of an oak tree? In what different ways can oak trees cause damage?
Some of the ways oak trees can cause damage include cracking foundations and sidewalks, causing damage to powerlines, attracting lightning, and causing damage to roofing. Mature oak trees over 20 years old are likely to cause the most damage due to their height and the length of their root systems.
Read on to find out all the different ways that oak trees can cause damage. We’ll also talk about some ways you can prevent or mitigate this damage so you can enjoy your stately oak tree for years to come!
Ways That Oak Trees Can Cause Damage
Let’s jump right into it! Oak trees can be wonderful to have in your yard. They’re often pretty to look at, tall, and the perfect centerpiece for your landscaping.
But sometimes, oak trees can cause damage to your home, and you won’t even know it until it’s too late. You don’t actually have to have an oak tree in your yard for it to cause damage.
If you live in an urban environment and your neighbor or the park nearby has an oak tree, there could be trouble lurking below.
Let’s take a look at the different ways oak trees can cause damage.
Damage To Sidewalks and Foundations
If you’ve ever walked down the sidewalk in a neighborhood or city, you’ve probably noticed some cracks and flaws in the sidewalk.
There are many reasons that a sidewalk might crack: the soil might simply settle and cause cracks, water may erode the concrete, or the sidewalk may have been put over the wrong type of soil (clay or sand, for example).
Another reason that sidewalks crack? Roots. Roots are an essential part of the tree, but because you can’t see them, they’re often forgotten about.
Most tree root systems are located 6-18 inches beneath the surface. This is just deep enough to remain unseen but shallow enough to cause problems above.
As the tree grows, so does its root system. The roots will continue to push outward in the soil, searching for nutrients and water sources to supply the rest of the tree. As the roots reach out to new soil, they can sometimes push into sidewalks and foundations.
How to Prevent Oak Tree Damage to Sidewalks and Foundations
To prevent roots from damaging sidewalks or foundations, you can purchase something like DeepRoot Tree Root Barriers. These come in a variety of sizes to fit any size tree. This product encourages roots to grow downward instead of outward, decreasing the chance of them damaging sidewalks and foundations.
A quick side note, while oak trees do cause damage, they are also great for the planet. You can read more about how oak trees are amazing for the environment here.
Falling Trees Can Damage Homes & Power Lines
This one may seem obvious. Of course, falling trees can damage homes and power lines, right? The problem with oak trees is that they are large trees compared to some other species, and they are susceptible to certain diseases that can cause them to topple over prematurely.
Some oak trees like the Laurel Oak, Red Oak, and Water Oak can grow up to 100’ at full maturity. That’s a big tree!
As you can imagine, it would take a heck of a storm to knock such a massive tree over. But storms aren’t all you need to be worried about with toppling trees. Just like people, trees can become sick too. Pathogens and disease can affect oak trees, making the trunk and branches weak.
Oak wilt, for example, will start on one branch of an oak tree but quickly spreads to the rest of the tree. Eventually, this disease will cause the tree to die, making its branches (or even the whole tree) more susceptible to falling.
One study from Environmental Management found that in a single county, the cost of removing oak trees affected by oak wilt was estimated to be in the wheelhouse of $18-$60 million over a decade-long period!
One of the biggest problems with oak tree diseases is that they can actually spread to other trees. When oaks are establishing their roots, if they are growing next to the same type of tree, they may graft their roots together for better survival chances.
If you’re interested, you can read about the most common oak tree diseases here.
The merging of these roots means that as soon as one tree is sick, the other is likely to contract the same illness. Some insects and other pests can also spread these pathogens.
An oak tree cannot choose where and when it falls, and sometimes rooftops and powerlines happen to be in the path.
How to Prevent Oak Trees From Damaging Home & Power Lines
If you are planting an oak tree or building a house near an oak tree, be sure to give yourself enough space and try to realize its eventual mature height—at least 20 feet. Pruning is usually not necessary for oak trees, but if you notice any wilting or damaged leaves, try to prune them to contain any sicknesses.
If you’re sure the tree is dead or dying, don’t wait to remove it! Get it done as soon as possible to prevent further damage from falling limbs.
Oak Tree Shade Can Prevent Other Plant Growth
Oak trees are known for providing tons of shade. In some instances, such as coastal live oaks, the trees may grow wider than they are tall, providing a wide area of shade.
Unfortunately for sun-loving plants, thriving next to an oak tree can be nearly impossible. If the grass isn’t already established under an oak tree, it can be tough to try to establish growth. And forget about planting any full-sun annuals at the base of an oak tree!
How to Encourage Plant Growth Near Oak Trees
If you’ve got a green thumb and you’re crafty with landscaping, you may be thinking of planting pretty flowers in some mulch at the base of your oak tree. Or maybe your oak tree throws some shade over your beautiful flowerbed.
No need to fret! There’s plenty of shade annuals you can plant that are still colorful and attractive, even without the sunshine! Many types of impatiens and begonias thrive in partial- to full-shade and come in a variety of colors.
If you’re having trouble establishing grass beneath your oak tree, try planting some shade-tolerant grass-like Scotts Turf Builder Grass Seed Dense Shade Mix. This particular mix can grow in as little as 3 hours of sun per day.
Be sure to pick the seed that’s right for your growing zone. This mix will only grow in transition zones.
Oak Trees Can Attract Lightning Strikes
Have you ever been told never to stand under a tree during a lightning storm? It’s for a good reason! Lightning tends to strike the tallest thing in the area, and, as we said before, oak trees can grow pretty tall.
If you’re inside your house and far away from any oak trees, you may be safe from the lightning, but your water pipes and electrical control boxes are not.
Remember how we mentioned before that oak tree roots grow to try to find as many nutrients and water as possible? Occasionally, roots will find their way into the water line or sewer system.
This can be a problem, especially when oak trees are the most popular tree for lightning strikes, according to Iowa State University. In fact, oak trees were struck by lightning about 200 more times than the next most popular lightning rod tree, the poplar tree.
Besides the damage from falling debris and possible fires that are caused by lightning striking trees, we have to consider where all that energy goes after it strikes the tree: Into the roots.
If a tree’s root system is touching or wrapped around a water line, the escaping energy can cause the water line to burst. Additionally, the electricity may ride along the water line until it reaches a control box and damages those too.
Trees touching or wrapped around sewer lines can cause similar problems that often require costly repairs and can leave homes without water for extended periods.
All in all, NOT the best situation to be in.
What to Do If Your Oak Tree Is Struck by Lightning
If your oak tree has been struck by lightning, assess the damage. If the damage is only to one side, the chances of the tree recovering are pretty good. You can prune the good side of the tree to help balance the tree out, but it’s a good idea to wait a few weeks to make sure the tree will recover.
Sometimes a tree that is struck by lightning will not show any outward damage aboveground. However, below the surface, the roots may have been damaged. If you notice leaves are beginning to die off and fall off the tree, watch the progress closely. The tree may recover, but if no new leaves form in the spring, the tree is probably not recoverable.
Our last tip is to help your tree recover faster by watering it and using fertilizer. This will help reduce the stress on the tree to find nutrients and recover from its wound. Healthy oaks do not need watering or fertilizer, but it’s a good practice for injured oaks.
Additionally, if you’re finding your tree roots are causing a mess underneath the ground, you can actually use vinegar to remove the tree roots.
Oaks Cause Yard Litter
Oak trees grow from acorns, and when the trees mature enough, they begin producing their own acorns.
The number of acorns produced from a single oak tree can vary widely from year to year. Some years there can be thousands of acorns in your yard from a single tree; other times, only a few.
Nonetheless, acorns and fallen twigs and branches can damage your lawn by covering the grass and creating unpleasant aesthetics.
This one may not bother you as much, especially if you enjoy watching little critters scurrying around your yard. But, if you live in a homeowner’s association, keeping up with the yard litter can be trying.
Preventing Oak Tree Yard Litter
Unfortunately, it’s hard to prevent trees from dropping their acorns! You can prevent some of the smaller twigs that are cut by squirrels by deterring those pesky critters before they make your oak tree their home.
Are Oak Trees Bad For Houses?
Now that all the downsides of an oak tree are laid out, you may be having second thoughts about planting one in your yard.
So, are oak trees bad for the home?
Oak trees are not bad for houses. All trees come with their own pros and cons. Ash and poplar trees are often cited as causing damage to home foundations, just like the mighty oak. Similarly, willow and elm trees are often susceptible to lightning strikes.
It’s all about what you want in a tree. If you’re looking for a large shade tree that’s going to be around for decades or centuries, the oak tree is a great choice! But there’s nothing wrong with a maple tree, with its distinctive leaves and helicopter-like fruits that float through the air each spring.
If you’re interested in planting an oak tree, check out our guide on the best places to plant an oak tree here.
How far Away From A House Should An Oak Tree Be?
Oak trees in the yard provide several benefits to the homeowner. They improve the scenery, are constant yet ever-changing throughout each season, and most importantly, they provide shade, shelter, and privacy to the homeowner.
The placement of the oak tree in relation to the home is important.
To provide the best shade and maximize its use, planting a tree in the southwest corner of the house is the best location, according to the University of Missouri.
In terms of distance from the house, large trees should be planted at least 20 feet from your home and no less than 5 feet from any sidewalk. You should also make sure that the tree does not hang over your house or any often-used walkways.
Additionally, we wrote a guide on if whether or not you should plant an oak tree in your backyard.
Are Oak Trees Bad For Grass?
Oak trees are known for providing tons of shade on a hot summer day, but not all grasses are okay with growing in the shade. Will an oak tree kill your grass?
It can be difficult to establish grass beneath an oak tree if it is fully mature. Many natural types of grass need at least partial sun to grow properly and photosynthesize. However, not all grasses need tons of sunlight.
As we mentioned before, there is grass seed out there that can work with as little as 3 hours of sun per day.
If grass is already established beneath your oak tree, try lifting your mower deck a little higher when cutting the grass within the tree’s spread (shade). Leaving the grass a little higher will help it reach any available sunlight.
Another problem with grass and oak trees is the competition for nutrients. When an oak is first growing, grass can sometimes out-compete the tiny tree for nutrients. But when a mighty oak is established, the tables will turn, and the grass can find itself scrambling to get enough nutrients.
It’s not a great idea to try to fertilize the grass as this can actually hurt an established oak tree. The best solution is to keep the grass a little higher than normal and let it thrive on its own. If it doesn’t seem to be working, try using a shade-tolerant grass seed instead.
Wrapping Things Up
Having oak trees in your yard and landscape can have tons of benefits for your home. It can frame your house, provide shade to lower utility bills, raise the value of your property, and be a nice-looking piece in your yard.
But oak trees can also create problems for your home. To recap, some of the ways that oak trees can cause damage include:
- Cracking the foundation of your home
- Cracking sidewalks
- Falling branches and trees can damage roofs
- Falling branches and trees can damage power lines nearby
- Oak trees can prevent sun-loving plants from growing
- Damage to waterlines via roots or lightning strikes
- Fire damage due to lightning strikes
- Sewer line damage due to roots or lightning strikes
- Yard litter from acorns and snipped branches
You can prevent or minimize the damage done by oak trees by knowing all the different ways they can cause damage and being prepared for each one.
Hopefully, after reading this article, you have a better understanding of all the different ways oak trees can cause damage, and how to prevent it so you can enjoy these lovely trees for years to come.
Haight, R. G., Homans, F. R., Horie, T., Mehta, S. V., Smith, D. J., & Venette, R. C. (2011). Assessing the cost of an invasive forest pathogen: a case study with oak wilt. Journal of Environmental Management, 47, 506-517.
Kovacs, K., Vaclavik, T., Haight, R. G., Pang, A., Cunniffe, N. J., Gilligan, C. A., & Meentemeyer, R. K. (2011, April). Predicting the economic costs and property value losses attributed to sudden oak death damage in California (2010-2020). Journal of Environmental Management, 92(4), 1292-1302.
McPherson, G. E., & Peper, P. P. (2012, March 27). Costs of street tree damage to infrastructure. The International Journal of Urban Forestry, 20(2), 143-160.
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