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Tree Care in Construction Zones

Photo: Colorado State University Extension

Trees provide many benefitsproducing oxygen, cooling neighborhoods, conserving energy, reducing pollution, serving as homes for wildlife, increasing a home’s curb appeal, and more. So it is no wonder that people tend to build in wooded areas.

What many people do not realize is that some construction practices can be damaging to trees. Oftentimes construction damage to a tree does not become noticeable for many months or years. A tree damaged by construction may look healthy, but if its root system is damaged the tree will slowly decline and may eventually die. Often insects and disease will invade the weakened tree and accelerate this process, making it harder to determine the cause of the decline. However, there are easy steps that contractors can take during the three phases of construction to protect trees on constructions sites.

Design Phase

The most effective way to limit tree loss is to carefully site buildings, driveways, sidewalks, septic systems, utility lines, and roads so that they avoid the trees you want to protect. Tree roots often extend out as far as the crown of the tree, so protecting the roots out to the drip line is important.

Construction Phase

The four most common causes of tree damage or death are:

  • cutting the tree’s roots
  • compacting the soil over the tree’s roots
  • changing the ground level around a tree during construction
  • damaging the bark by collision with heavy machinery

In order to save selected trees, clearly mark each tree by building a temporary exclosure of brightly-colored material around the tree so that workers can clearly see the areas where equipment must not be parked or driven.

Contractors should:

  • minimize soil compaction from heavy equipment
  • limit the elevation change around trees
  • park heavy equipment away from trees
  • keep large amounts of stone or soil out from under the tree’s dripline

Post-Construction Phase

Adequately water trees during dry spells both during and after construction. Soil should be moistened to a depth of approximately 12 to 18 inches.


Illinois Department of Natural Resources Link
The National Great Rivers Research & Education Center Link 2wav Link