How to Prevent Hazardous Trees
Top 10 Ways Trees Become Hazardous
10. Lack of Knowledge of Trees
9. Lack of Concern for Trees
8. Lack of Space for Trees
7. Automobiles
6. Improper Planting
5. Lack of Aftercare
4. Too Little or Too Much Water
3. Improper Pruning
2. Topping
1. Construction Damage

Module 1: How to Prevent Hazardous Trees

Yes, it is true; most hazardous trees are preventable. Hazardous trees are often created when people lack the knowledge of what it takes to keep trees healthy, and by the ignorance of how their actions can unintentionally lead to the decline and eventual death or failure of a tree. This module provides an overview of what it takes to prevent trees from becoming hazardous.

If you have a tree that you think may already be hazardous, consider hiring a Certified Arborist to conduct a Hazard Tree Assessment. This involves determining the likelihood that a tree or part of a tree will fail and injure people or property and assessing risk factors that may contribute to the eventual failure of a standing tree.

When a tree becomes hazardous, it often fails, which means a limb falls out of the canopy of the tree, the trunk splits and falls to the ground, or the entire tree becomes uprooted, and people are often injured and property is damaged or destroyed. Because trees are living organisms growing in varied dynamic environments, it is impossible to predict exactly when a tree will fail. Weather often plays a role in tree failure. Extreme wind, rain, snow, and ice can cause perfectly healthy trees to fail. But usually it is the trees that have some defect, decay, or damage that fail under extreme weather events. Fortunately, this tree failure is often preventable through proper planning, planting, care, and maintenance of trees.

Hazardous trees are often created through human influences. Rarely do environmental factors create hazardous trees; usually these factors just contribute to the timing and severity of the tree failure. By understanding what circumstances create hazardous trees, you can learn how to prevent trees from becoming hazardous.

Now that you understand what a hazardous tree is, and know that hazardous trees are preventable, click on the NEXT arrow for a look the top 10 most common mistakes that can create hazardous trees and lead to the decline or death of trees.


The Hazard Tree Prevention Webpage is  a production of the Pacific Northwest Chapter, International Society of Arboriculture