Trees and How Their Roots Can Cause Problems

There is nothing more beautiful than a tree, whether it is gracing the entrance to your yard or shading a porch or sidewalk. While many worry about how big a tree will get and whether its branches will break off and be of danger to their home or overhead wires, few remember to also look below and take caution of that tree's roots.

What ways can tree roots be a problem you might ask? Here are just a few things that can get damaged due to intrusive root systems:


1. Underground Pipes - A tree's invasive roots can affect old pipes that are barely holding together. Although pipes being broken by roots isn't a common incident, it still can be an issue. Many times the pipes are already leaking, giving the tree extra reason to grow larger and larger, stimulating root growth toward the break in the pipe. Species of trees that are most problematic to pipes are poplars, willows, and silver maples. If your trees roots have already infiltrated your pies, it could be a hassle to repair but it is still possible. Instead of removing the tree you can replace the faulty pipes with something more durable. This will not only be the easiest but possibly the cheapest and the best solution long term.

2. Septic Systems - Roots in your septic system is a common problem for many homeowners. Trees roots cannot only enter your septic tank area but also the leach field that drains your septic. The most common specie of trees that cause such problems are willow, maple, and elms. If you already have a problem with your trees roots blocking your septic tank, then you know it requires a professional to clear your system. There are chemicals you can buy for your septic systems that will kill roots, but the best solution is not planting trees too close to your septic tank.

3. Foundations - If you have seen a home with cracked flooring and walls, many look for a nearby tree planted too close to the house. While roots can occasionally be the cause of foundation damage, most homes' foundations are ruined due to the soil beneath the house drying and settling. Soil subsidence is a common reason for damage to a home's structure. Under very special circumstances roots can actually contribute to this problem. What is soil subsidence? It is when soil shrinks during periods of drought and expands when there is a lot of moisture. This shrinking and expansion shifts a home's foundation and eventually can cause walls in the home or flooring to crack.

4. Sidewalks and Pavement - Most of us have seen this kind of damage as we walk along a sidewalk and it begins to buck and roll where a tree is nearby. Roots from trees can crack or lift side walks, drives ways, and other paved surfaces. Trying to severely prune a tree to stop this damage from occurring rarely works and most likely will kill the tree. While having shade over a sidewalk sounds wonderful, it's only a matter of time before the tree grows too big and the roots began to cause that sidewalk damage.

If you installing the sidewalk and the trees at the same time, you can put in root barriers around the sidewalk as well as curbs, gutters, parking lots, and driveways. This will help to reduce the trees growth. These barriers are placed in the soil to a depth of 18 to 24 inches by trenching along the area to be protected. If trees are too close to pavement, or if compacted soil forces large roots to grow very near the soil surface, roots can eventually lift pavement. When roots encounter a paved area, the only entry is often a gap between the soil and pavement. Future problems can be prevented at the time of planting by using smaller plants, providing a minimum distance of 4 feet between the tree and the pavement, or using mechanical barriers to prevent roots from growing under the pavement. Remedies for lifted pavements around mature trees often involve either moving the pavement away from the tree or pruning off the problem roots. Cutting off the problem roots often causes stress and instability. Trees without sufficient root support can be blown over more easily in a storm.

Roots do not have to be a problem, it is just a matter of examining where you plant your trees in relation to objects you know that can become damaged. And if that tree has already been planted, don't despair, there are solutions for you to consider.

Andrew Johnson is the owner of Central Texas Tree Care, a leading tree service provider in Central Texas (Travis County and surrounding areas) offering services such as pruning and removals, cabling and bracing as well as arborist reports, diagnostics, pest management, fertilization and Austin tree service trusts. For more information please visit http://www.centraltexastreecare.com.

Protecting Your Trees Roots

There is a common belief that a trees root system is reflected by its crown above. Unfortunately this is not true. So if you are looking to dig around your tree, whether it is to plant other plants or even to build something such as a house or garage, its best to understand how a trees root systems work so that you can protect your tree's health.

There are many ways a tree can be damaged, the less obvious is the damage that occurs underground. Roots are vital to a tree's health as they are responsible for its nutrients and water uptake, they help the tree store energy, and they anchor the tree. Trees are never the same shape below ground as they are above, so it is difficult to predict the length or location of a tree's roots. The rule of thumb is that approximately 90-95 percent of a tree's root system is in the top three feet of soil, and more than half is in the top one foot. If you are planning to disturb the ground around a tree, the part of this root system in which construction damage should be avoided is called the Protected Root Zone (PRZ).

One common method used to identify the tree's PRZ is to define it as the "dripline"--the area directly below the branches of the tree. However, many roots extend beyond the longest branches a distance equal to two or more times the height of the tree. For this reason you should protect as much of the area beyond the dripline as possible.

While the above mentioned is ideal, unfortunately, in most places, space around a tree, especially on construction sites, is limited. In these situations, the rule of thumb sometimes has to be bent. When this occurs, one then has to evaluate how close to the roots one can dig without threatening the tree. The good news is that healthy trees can survive after losing 50 percent of their roots. However, other species are extremely sensitive to root cutting, even outside the dripline.

When digging, if possible, try not to disturb no more than 25 percent of the roots within the dripline for any tree. When dealing with trees that have been growing in the forest or that naturally have a narrow growth habit, an approach called the "critical root radius" is more accurate than the dripline method for determining the PRZ. This is particularly true for columnar trees and for those where competition has reduced the canopy spread.

To calculate critical root radius, begin by measuring the diameter at breast height (dbh). This is done by measuring the tree's trunk diameter (thickness) at a point 4.5 feet above the ground. The measurement should be done in inches. For each inch of dbh, allow for 1.5 feet of critical root radius for sensitive trees, or 1.0 feet for tolerant trees. For example, if a tree's dbh is 10 inches, then its critical root radius is 15 feet (10 x 1.5 = 15). The PRZ is an area around the tree with a diameter of 30 feet (2 x radius), and is the area in which a critical amount of the tree's roots may be found.

If construction is to occur in an area with numerous trees, it may be necessary to remove certain trees and decide which ones will be protected. In this case, develop a landscape protection plan. Obtain a set of site development plans that include where proposed buildings will be placed or even sidewalks and utility lines. Work with the builder on which trees can be saved and protected. Keep in mind that the builder can possibly shift locations of buildings slightly if there are certain trees you are set on protecting.

There are many ways to protect your tree's root systems when working around them, the first requires evaluating and understanding how a tree grows and its root sensitivity before putting a shovel into the ground.

Andrew Johnson is the owner of Central Texas Tree Care, a leading tree service provider in Central Texas (Travis County and surrounding areas) offering services such as pruning and removals, cabling and bracing as well as arborist reports, diagnostics, pest management, fertilization and Austin tree service trusts. For more information please visit http://www.centraltexastreecare.com.