Column: How The Mighty Have Fallen

How The Mighty Have Fallen
Los Alamos Extension Horticulture Agent

Following the rainy season, we have seen a number of fallen trees throughout the community. Are your older trees ready for the next big storm? Are you concerned about a tree falling over, or a large limb crashing down on your house or car? It is during the seasons of rainy and windy weather when trees that have become hazardous make their presence known. 

How can you tell if you have a hazardous tree before it lands on your house? First, inspect your trees regularly, both before and after storms. If you see a potential hazard, keep people, pets, and vehicles out of the area until the problem has been corrected.  If you need help, call the Cooperative Extension Service or a certified arborist to identify and correct the hazardous condition.  Here are some warning signs of a potentially hazardous tree: 

  1. Lean: If your tree has suddenly started to lean, it has lost its root anchorage and is in the process of falling. The soil may be mounded up or roots may be exposed on one side. Your “leaner” requires immediate action. Don’t let young trees become leaners, either.  Remove stakes after one year to promote good root anchorage, and prune to allow your tree to stand up straight. Try not to disturb roots of established trees by excavating around them.

  2.  Multiple Trunks: Codominant stems are usually weakly attached and prone to splitting. Inspect the point where the trunks meet for cracking, which indicates a high potential for the trunks separating in the next windstorm.

  3. Weakly attached branches: Inspect large branches at the point where they attach to the trunk. If a split exists, the branch is prone to breakage. Trees with many branches arising from the same point on the trunk (which can occur after the mistaken practice of topping) are weak and potentially hazardous.

  4. Cavities or decay: Look for large cavities in critical places like where branches meet or at the base of the tree. Mushrooms and conks (bracket-like growths) growing on the bark or roots indicate rot. Don’t attempt to seal a cavity as it may do more harm than good. 

  5. Trunk and branch cracks: Inspect the trunk and large branches for cracks that extend into the wood. If the crack is three inches or deeper, it indicates a separation of the wood within the tree. Shallower cracks, in the bark alone, are not usually a problem. An arborist will be able to determine whether pruning or more extensive measures are needed.

If your inspection indicates a need for professional help, whom should you call? The best assurance of getting quality advice or tree work on a hazardous tree is by hiring a certified arborist. A certified arborist has passed a proficiency exam and receives continuing education. Some non-certified arborists may also provide competent work. Always verify insurance coverage and check references to make sure you’re getting the best possible service. 

For more information on hazardous trees or other horticulturally related questions, call the Cooperative Extension Service at 662-2656 or email

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