If you’re planning a landscaping, construction or home improvement project this year, take steps to protect your valuable trees before finalizing project plans.
Depending on the project, some trees may need to be removed prior to starting work. Be sure you understand whether that requires simply removing the tree or removing the stump as well.
Other trees and large shrubs can be saved, but realize that nearby construction can cause unseen damage that will only be evident later. The better the protection procedures you put in place, the better the outcome for your trees.
How Construction Projects Harm Trees
Trees are much more than what you see above ground. Underground root systems are vital for trees’ health, enabling them to get water, oxygen, and vital nutrients from the surrounding soil. Roots also work as an anchoring system to keep trees securely rooted, especially during high winds and storms.
Unfortunately, landscaping and construction projects can easily injure tree branches, trunk and/or roots, leaving trees stressed, damaged, or no longer stable after the work has been completed.
It’s not just major construction projects that cause this kind of outcome. Activities that can harm and injure trees include:
- Putting down sod – Tilling the ground kills any tree roots nearby.
- Installing an irrigation system – Often, many roots are cut to install underground irrigation lines and sprinkler heads
- Building a deck or a playset – Root cutting, soil compaction, and adding too much mulching material are all detrimental to tree health
- Adding a fence
- Creating a sidewalk, walkway, or driveway – Oftentimes, herbicide is placed under asphalt, killing tree roots beneath it. Plus, roots cannot get enough oxygen under paved surfaces.
- Erecting a shed, garage, or extension
- Adding soil – Roots in the top 6 to 12 inches of soil absorb moisture and nutrients to sustain the tree. Adding even a few inches of soil can smother and kill the roots, cutting off their oxygen and water supply.
- Changing the grade of the surrounding land – This usually involves adding or removing soil and cutting roots, both which can be deadly to a tree and decrease stability.
- Soil compaction from heavy equipment – Trees need about 50% “pore space” in the surrounding soil for water and air flow. When heavy equipment compacts the soil, it becomes much more difficult for a tree to grow roots, gather water, or receive oxygen.
- Removing surrounding trees that were acting as protection from the elements – Trees work together, especially in forest settings, and sometimes removing a neighboring tree can cause injury and stress to those it was protecting. Whether it was providing protection from sunlight, high winds, or both, the loss of the tree can cause injuries such as sunscald and broken limbs to its neighbors.
- Getting too close to the action – During construction and landscaping projects, trees often suffer from broken branches, peeled bark, equipment running into the tree and damaging the trunk, and more.
See examples of damage to trees during projects in this fact sheet from the Colorado State University Extension.
Knowing that these things can severely harm and/or eventually kill a tree, what should you do to prepare for any kind of construction on your property?
Planning is Important
It is much easier to prevent problems than to try to fix the damage afterward. Consult with an arborist to create a tree protection plan before work begins. We can advise you on the best course of action and will let you know any possible ways to keep existing trees.
Some things you can do to protect your trees include:
- Have one route for heavy equipment and, to the extent possible, limit equipment to only that route. This way the ground being compacted is limited to a specific area.
- Have a plan for where equipment will be stored so it will not damage trees or landscaping.
- Fence off trees using sturdy, visible barricades. We suggest doing this even if you’ll be the only person working on the project; it’s easy to accidentally damage trees that aren’t fenced off.
- Protect as much as the tree above and below ground as possible. Barriers should reach at least to the drip line (where the canopy ends) for trees less than 4 years old, but for all other trees, we recommend that you place the fence one foot from the trunk for each inch of trunk diameter.
- Ensure that no digging, placing of dirt, or traffic is allowed within the fencing.
- Check on the barricades throughout the project.
Communicate all of these things to any contractors or landscapers you may be working with. If needed, schedule an on-site meeting before the project begins so everyone is clear on which trees will be protected.
While the project is in progress, continue open communication with everyone on the property. Visit the site often, if possible, and ensure that all protocols are being followed.
Taking Care of your Trees after the Project is Over
If tree damage did occur, it is often irreversible. Consult an arborist immediately to see if the injured trees can be saved or if they need to be removed.
Even if you don’t notice any obvious signs of damage, it’s best to get a professional tree inspection. If roots were damaged or aren’t receiving vital nutrients, the tree will slowly begin dying.
After the project is completed, trees will need a little extra TLC for a few years. Check for any open cuts or wounds where pests or diseases could gain easy access to the tree. Stressed trees are more susceptible to health issues even if they don’t have an open wound, so keep a close eye on them following construction.
The trees are also adjusting to any environmental changes that happened around them. Depending on the circumstances, we may suggest corrective pruning, fertilization, pest and disease control options, or other treatments to ensure the health of your trees.