Protecting the existing trees begins when you plan your home. Select a building site that is large enough to accommodate your house and still allows room for undisturbed areas of trees. Small wooded lots are not practical. Many of the trees will have to be removed to make room for the house, and the remaining trees will be damaged by grading and other activities that go with home building.
Trees vary in their ability to tolerate construction damage. Among the most sensitive are red oak, white oak, and sugar maple. These species will need more protection during construction. More tolerant trees include bur oak, silver maple, poplars, and willows. In general, young trees are better able to withstand the changes that construction brings than are large, mature trees.
Select a home design that will disturb the area around the tree as little as possible. Keep in mind that the trenches dug to install underground water pipes, gas and electric service, telephone and sewer lines will damage or destroy part of a tree’s root system. With your blueprints in hand, consult the different utilities to plan service installations as far from the tree as possible.
Plan your driveway to minimize damage. Locate it as far from trees as possible. Limestone gravel placed over the tree’s root system will change the chemical makeup of the soil, resulting in poor growth or yellow leaf color. Paving a driveway shuts off the supply of air and water to the root system and suffocates the tree.
Work with builder to avoid damage
Most of a tree’s feeder root system is within the top foot of soil. In fact, many roots grow in the organic litter that has accumulated under the tree. The root system extends at least as far (often farther) than the ends of the branches.
Remember, mature trees have been growing in the same place for many years. The tree developed roots at a soil depth optimum for absorbing the nutrients, moisture, and oxygen that are necessary for the growth and survival of the tree. If the root zone is disturbed by adding fill, cutting away soil or moving heavy equipment over the root zone, the tree is almost sure to suffer.
One of the most common (and most destructive) causes of construction damage to mature trees is to add soil, thereby burying the roots. When this happens, the roots lose their supply of oxygen and water. If you must add soil fill around the tree, use a porous soil, like a sandy loam, that will let the roots “breathe.”
Or, put a layer of gravel (not crushed limestone) over the root zone before adding soil. Small, circular pits dug around trees to keep soil fill away from the base of the trunk seldom preserve trees, because the soil fill outside the well covers the major portion of the fine roots system. Avoid stock piling topsoil or construction materials around trees during construction. On the other hand, removing topsoil during home construction will damage the feeder roots. Without their protective soil covering, the roots are subject to drying and injury.
Ask your contractor to keep heavy equipment away from the trees. Build a fence around the roots system if necessary. Broken branches, torn bark, and crushed roots not only hurt the tree, but make it more open to disease and insect invasion. Driving heavy equipment near trees will compact soil and damage the roots. Before construction begins, you may want to cover the root area with several inches or wood chips to minimize compaction. Please visit this link for a Tree Protection Specifications example.
If at all practical, preserve the natural habitat of the tree, both during and after construction. For example, oak trees thrive in acid soil. Their fallen leaves help create and maintain acidic surface layers of the soil that differ significantly from the alkaline material below. If you clear away the natural undergrowth, establish a lawn and rake up the leaves each fall, you will eventually change the upper soil surface, and the oaks will decline and possibly die. Try to maintain the natural drainage pattern of the site. When grading changes the undergrowth flow of water that the tree is accustomed to, the tree will suffer.
Visit this link for more information about Protecting your Trees during construction.
For more information on preventing construction damage to trees, contact your certified team of arborists at Woodland Tree Service.
Please email joanna@woodlandtree.com or call us at (901) 309-6779.