Trees help complete the look of your home by providing shade, privacy, and character. Before you go pondering which tree will look the most aesthetically pleasing, however, you first need to think about which trees are actually suitable for planting near your house.
Certain trees have wide-reaching and invasive root systems which can eventually cause damage to your sewage lines and foundation. These are costly repairs, which are sometimes irreversible if the problem goes unnoticed for too long.
What you want to look for are trees where the roots grow straight down. Or, smaller trees with shallow and non-invasive root systems.
The safest trees to plant near your home are pines, magnolias, dogwoods and Japanese maples. Pines have unique non-invasive roots that grow straight down, rather than outward. Magnolias, dogwoods and Japanese maples have shallow root systems with a small footprint that won’t cause damage to your home.
We’ll take a look at exactly why these trees win out over others, and which other trees you should avoid.
Types of Tree Roots
There are three main types of tree roots. Knowing which species have which roots will help you make a more informed decision about the trees you plant near your home.
Lateral Root System
The most invasive and destructive trees are trees with lateral roots. About 80% of trees have lateral roots. Lateral roots like to grow outward, as this is how the tree gains stability and more access to groundwater.
In fact, a typical tree can spread roots two to three times larger than its crown. When you think of how big some shade trees can get, it’s easy to imagine how much damage those roots could potentially do. Aggressive lateral tree roots tend to grow under the home and push upward on the foundation, causing it to buckle.
Trees with aggressive lateral roots that should not be near homes include oaks, aspens, poplars, weeping willows, and cottonwoods.
Dogwood, Japanese maple, and magnolia trees all have lateral roots. But the key is that their root system is non-invasive, so their spread is predictable.
Oblique (Heart Root) System
Oblique root systems are anchored into the ground with a root ball. Trees with this type of root system tend to rely on the stability of the soil and the counterweight of the root to stay upwards. These roots tend to grow both downward and outward.
Oblique root systems are more common in regions with dry soil, like the Mediterranean. These trees tend to become unstable in wet soil, so they’re certainly not a great choice to plant anywhere near your home.
Common North American species with oblique root systems include sycamore and red oak.
Taproot System
The least common type of root system is a taproot system. These roots can be found in pine trees, which also have generally deep root systems. The taproot is the primary root, which is sent down into the ground in search of water. This strong root gives the tree stability, allowing it to grow tall.
Many trees with taproots also grow roots horizontally as the tree matures. This includes pines. However for the most part, pines are considered safe for foundations, and their roots prefer to find water deep in the ground.
But don’t mistake all trees with taproots as safe for your home! The notorious oak tree has a taproot that tapers off at about 3 to 5 feet (1 to 1.5 m). From there, it grows an aggressive lateral root system that is well-known for damaging foundations.
What Tree Can Be Planted Close to a House?
When you’re considering planting a tree near your home, you not only need to think about the roots invading the foundation. You should also consider if the tree is stable enough to stay rooted in storms. Also, consider the effect of branches falling on your house—the bigger the tree the more damage those branches can cause.
Large trees like pines are safe for your foundation, but should still always be planted at least 20 feet (6 m) away from your house. This will help you avoid hazards like falling branches, although you may miss out on certain benefits such as shade and privacy.
Smaller trees no higher than 25 feet (7 m) can be planted as close as 8 to 15 feet (2 to 4 m) away from your house. This includes dogwoods, magnolias, Japanese maples, and most smaller fruit trees. These lovely tree species will give you the shade and privacy you need – without the risks!
Best Small Trees With Non-Invasive Roots
Small trees with non-invasive roots such as dogwoods, magnolias, and Japanese maples are some of the best trees to plant near the home. They give adequate shade, have non-invasive roots, and present less risk of damaging your foundation or falling on your home. Let’s weigh the pros and cons of these types of trees.
Japanese Maples
Unlike larger maple species such as the silver maple or Norway maple, the Japanese maple has non-invasive lateral roots. As it is a smaller tree in general, its root system has a much smaller footprint. You can plant a Japanese maple as close as 10 feet (3 m) to your house without worrying about foundation damage.
These trees also have shallow roots, which makes them great as indoor potted plants as well! Typical Japanese maples grow to a maximum of 30 feet (9 m) high. Dwarf varieties grow more slowly and only reach up to 8 feet (2 m).
Dogwoods
These beautiful blossoming trees are a quaint and ornamental addition to any front yard. As a smaller tree species, their root system doesn’t extend too far, so they are safe for foundations. They have very shallow roots, which makes them more of a hazard for driveways and sidewalks than foundations.
Standard dogwoods can be planted 15 feet (4 m) from the home without any worry about the roots causing damage.
Magnolias
Perhaps the most beautiful flowering tree of all, magnolias are a prized plant to have near the home. In the springtime, their white and pink blossoms emit a sweet, potent fragrance.
Their roots are not invasive, but they do spread laterally and close to the surface. They won’t burst through your foundation like a willow tree, as their roots are very soft and rope-like. The biggest issue with these trees is that the roots can sustain damage if the tree is planted too close to your home.
Certain, larger species of magnolia trees can develop quite extensive root systems. Consider planting smaller species such as star magnolia or lily magnolia. Star magnolia only grows to a maximum height of 20 feet (6 m) and can be planted 8 to 10 feet (2 to 3 m) from your home.
How Close to a House Can an Oak Tree Be Planted?
Although they’re one of the most notorious trees for destroying foundations, there’s no denying the charm and beauty of oak trees. They have uniquely shaped leaves, provide excellent shade, and even drop cute little acorns!
Oaks are also a symbol of strength, as characterized by their large size. Their trunks can grow 70 feet (20 m) high and up to 7 feet (2 m) wide. Their branches can reach as wide as 135 feet (40 m)!
What makes oaks so dangerous around homes is their strong, far-reaching root system. Unlike most trees whose roots spread two to three times the size of their canopy, oak tree roots can spread up to seven times the width.
If you consider the fact that oak tree roots can grow so wide, it’s best to avoid planting them near the house altogether. Their roots won’t cause issues now, but 20 to 30 years down the road you may run into problems. At a minimum, plant oak trees 50 feet (15 m) away from the home.
What Is the Best Shade Tree That Grows Fast?
Many larger shade trees need to be planted at least 20 feet (6 m), and often considerably more, away from your home due to their size. So what shade trees will give you relief in the summer, can be planted relatively close to your house, and won’t take decades to grow?
Red maple, also known as amur maple, is a native North American tree that can grow 2 feet (60 cm) every year. Its fiery leaves are not only aesthetically pleasing and shady, but the root system of this tree also has a small footprint. That means it is safe to plant close to the home.
Water Birch is another fast-growing tree that can add 13 to 24 inches (33 to 61 cm) in height each year. Keep in mind that they grow tall (up to 90 feet, or 27 meters) and require very wet soil. Their roots are not invasive, but their need for constant moisture may spell trouble for your foundation.
What Does It Mean When Tree Roots Come to the Surface?
Surface roots have many different causes. Some trees simply have shallow roots that regularly breach the surface, such as willows and poplars. Other times, surface roots begin to show due to the erosion of soil around the tree. This can be caused by foot traffic or heavy rain.
But one of the most common causes is poor soil. Compacted soil or poorly draining soil does not give new roots enough space to grow freely. So, the new roots push the older roots out of the way and towards the surface. This also happens when trees are planted in too small of an area, such as up against a house.
Which Tree Has the Largest Root System?
A quaking aspen forest colony in Utah called Pando is believed to have the largest root system of any tree. All 47,000 trees in the forest actually share the same root system, making it a single organism! The length of that root system? 107 acres (43 hectares).
Pando is an anomaly, but there are other trees around the world with extremely large root systems. One of the deepest tree roots discovered was in the Kalahari desert in Africa. The tree was a Boscia albitrunca (Shepherd’s tree) and its roots traveled 230 feet (70 m) below the surface in their search for water.
Summary
It can be difficult to find landscape trees whose roots grow solely downward. This is because 80% of trees have lateral roots which spread horizontally.
Pine trees are one of the few common trees whose roots grow straight down, but they are not necessarily the best tree to grow near the home due to their size. Also, keep in mind that their roots can begin to grow laterally over time.
Small trees with shallow and non-invasive root systems are the safest to plant near your home. This includes trees like dogwoods, magnolias, and Japanese maples.
Despite their beauty, you should always avoid willows and oaks, as their roots spread far and are incredibly invasive.