Actions Harmful to Trees


The best friend on Earth of man is the tree. When we use the tree respectfully and economically, we have one of the greatest resources of the Earth.

    —Frank Lloyd Wright

In urban areas humans often put trees under extraordinary pressures. Ultimately these pressures can affect their health and shorten their lives.

A squirrel or a bird can plant a tree, but trees rely on people to plant them in suitable locations and take good care of them. When we plant a tree in potentially adversarial circumstances its beauty and benefits cannot be achieved. People commonly plant trees in places where they are ill-adapted to site constraints and environmental conditions. Ultimately, these trees often pose a risk to people and property and are frequently mismanaged. Mismanagement increases their risk for pests and pathogens and ultimately reduces their life expectancy.

The average tree in metropolitan areas survives only about eight years. Of every four city trees that die or are removed, only one is replaced on average. Bruce Hagen, Certified Arborist, retired professional forester and author writes, “Pruning is best used to maintain safety, strong structure, provide clearance for cars and pedestrians, avoid conflicts with structures or overhead powerlines, minimize risk of wildfire, and enhance shape and attractiveness. When done without regard to a tree’s health, function, basic structure, appearance, and inherent value, it can be disastrous.”

Do you know how long it usually takes a tree to reach its most productive stage of carbon storage? About ten years. Urban trees need us, we need them, and wildlife need them too! We may own a tree, but we don’t necessarily know what’s best for it. Trees should be cared for by certified professionals.

Here are examples to assist you in recognizing the actions that harm a tree.

We are deeply grateful to Bruce Hagen for supplying and explaining photos for this project.

Additional Resources:


Trees and Infrastructure Damage


Improper Watering


Poor Tree Planting and Planning


Improper Pruning


Other Actions tha Harm Trees


Improper Grading and Compaction

Please click on the photo representing each group to access its full gallery. You may obtain a larger view of any photo in any gallery by clicking on it.