Tree Roots

Tree roots without question are an important part of the tree, if not the most important part. The nutrients and water that a tree needs to survive come in via the root system. Every branch, every leaf is supplied in this way. When roots become comprised, the tree can die. If roots for example are in some way cut or severed, tree damage is likely to occur. Severing roots undermines the health of the tree, weakening its intake system and hurting the tree’s overall stability. 

Root Structure

In order to understand the importance of tree roots, you need to understand how a root system works. This system contains both large perennial roots as well as smaller feeder roots that tend not to live as long. The larger roots are the heavier woody ones. They can usually be found within the top 6 to 24 inches of soil and do not grow deeper than 3-7 feet. Consider these roots the tree’s anchor. Here is where food and water get stored. Here is also where nutrients and water make their way into the tree. 

Feeder roots, on the other hand, are quite smaller—right around 1/6th in diameter. These however do make up the bulk of the root system’s surface area. They also are responsible for mineral and water absorption and to this end, grow upward, more toward the surface of the soil. As noted, these roots are short-lived. They tend to die regularly and then get replaced. All together, the root system of a tree, to give you a general idea, is approximately 2 to 4 times the diameter of the tree’s crown. 

Root Problems

There are many ways that roots can develop problems. Soil compaction is perhaps one of the primary ways that root systems become damaged. Construction equipment is a leading cause of soil compaction. Heavy machinery driven over roots can significantly compromise them. 

Another problem for roots is a change in soil depth. Adding soil atop roots can lead to oxygen reduction and lack of water. Even adding 4-6 inches of soil reduces the tree’s access to minerals and water. By the same token, a decrease in soil depth can be just as harmful to the tree. Soil acts as a buffer for the roots. When soil gets removed, the roots become more vulnerable to injury.

Improper watering is yet another major issue in terms of undermining a root system’s health. Overwatering reduces the amount of oxygen the tree gets. Whereas, underwatering hampers the growth of the roots. Additionally, it is important to keep in mind that roots need a fair amount of space in which to grow. If there is an insufficient amount of room, problems will likely develop. 

Tree Damage and Disease Symptoms

The Morton Arboretum notes that over 80% of all landscape problems originate underground. Given this fact, we can easily see that a root issue is going to affect the entire tree and could in the end lead to tree failure. The above problems to include, soil compaction, improper watering practices and soil depth changes, put tremendous stress on trees. A stressed tree is one that is more prone to disease. Fungi attack tree roots. When the large perennial roots are attacked, a number of problems arise—everything from growth suppression to the decay of food transporting cells. And when the small feeder roots are attacked, they develop problems absorbing the necessary water and nutrients. 

How can you tell if roots are dead and/or dying? A primary symptom is unhealthy looking foliage. Also, fungal growth may appear at the base of the tree as well as under the bark. Insects attack by chewing, sucking, or boring. Insects can do a great deal of damage to ae tree. From affecting the leaves to disrupting the transfer of minerals and water, such damage can be irreversible if the issue is not addressed. 


Because root problems lead to issues with the entire tree, prevention is imperative. A couple of guidelines to keep in mind: 

    • Keep soil uncompacted
    • Ensure adequate soil depth.
    • Ensure adequate water and nutrient supply. 
    • Ensure adequate space for roots to grow.

Evergreen Arborist Consultants, Inc., is a tree root specialist in the Los Angeles, Orange County and San Diego Areas. We provide expert witness and litigation support when it comes to construction defect, tree root damage cases, and roots that compromise sidewalks, foundations, and sewer pipes. We also offer consultations for cutting tree roots. Call or email us today.