How to Protect Your Community's Trees from Uprooting

Uprooted Tree

Winter Weather Tears Trees Down

Trees provide a multitude of benefits for communities and neighborhoods such as increasing property value and adding a bit of character to a home. In fact, a survey by Arbor National Mortgage, Inc. revealed that…

  • 84% of real estate agents think a house on a lot with trees is more sellable than a house on a lot without trees
  • 62% of the respondents said that the existence of healthy shade trees strongly influences a potential buyer’s impression of a block or neighborhood
  • 60%  thought healthy shade trees have a big effect on a potential buyer’s first impression of a property

People are almost naturally drawn to communities with mature trees because of the benefits and ambiance that lush leaves provide. Yet, every winter season there are dozens of storms that affect a community’s trees, and sometimes our best efforts to protect our community’s trees seem futile against the forces of nature.

When trees fail, they can be destructive and deadly. An attorney who works specifically with tree litigation cases made this statement:

Trees can be managed, but they cannot be controlled. To live near trees is to accept some degree of risk. The only way to eliminate all risk associated with trees is to eliminate all trees.

It seems that neighborhoods have always had an ongoing love-hate relationship with trees. People love to surround themselves with their beauty, admire their strength and stature, and are in awe that some have survived for so many years. On the other hand, communities dread the day of their failure.

Here are a few methods for homeowners and HOAs to help their trees endure the winter months.

Inspection by a Certified Tree Care Professional

Having your trees inspected by a certified tree care professional, or arborist, is the first step to preparing for the winter months. Certified arborists should provide an unbiased evaluation of what needs to be accomplished and can give you a greater understanding of tree needs to help you feel more comfortable with tree maintenance practices. For best results, try to have such inspections done well before the winter season arrives.

A certified arborist plays a vital role in tree protection and preparation to every property owner with mature trees. Arborist certification requires ongoing training and education on an annual basis to ensure the arborists maintain up-to-date, working knowledge of how trees respond in different situations. Arborists are therefore certified in their ability to prepare trees for adverse weather conditions.

These individuals differ from California licensed tree contractors and landscapers by the state of California as a tree contractor or landscaper in two important ways:

  1. California does not provide or require any specific educational testing of one’s knowledge of tree care for their licensed contractors.
  2. California does not require any ongoing education for the contractor to retain his or her license. Certified arborists, however, must do this to keep their certifications active.

Learn more about the benefits of different professional tree care certifications

Homeowners and HOAs should keep in mind that arborists cannot feasibly detect every condition that could possibility lead to the structural failure of a tree. Trees are living organisms, and they can fail in ways we do not fully understand. Adverse conditions are often hidden within a tree’s structure or below ground. Arborists cannot guarantee that a tree will be healthy or safe under all circumstances or for a specified period of time. Likewise, results of remedial treatments, similar to medicines, cannot be guaranteed.

Practice Proper Pruning Techniques

Trees should be properly pruned using the principles of tree care developed and standardized by the International Society of Arboriculture (a society that promotes the professional practice of tree care). Trees are often susceptible to damage and collapse because of the way they are pruned.

Popular Pruning Methods that Harm Trees

Some of the most widespread pruning techniques, such as topping and lion’s tailing, actually damage trees by changing the tree’s natural structural integrity. Trees that have been topped become hazardous as they replace their canopies. Generally the new growth is weakly attached to the tree and is subject to failure and collapse, especially as the branches become larger. The failure usually happens during wind storms.

Lions tail tree pruning exampleAn example of Lion's Tailing

Lion’s tailing is a pruning technique that has become extremely popular, reaching epidemic proportions. Lion’s tailing occurs when all the living foliage is removed from the center of a tree. The limbs of the tree resemble a lion's tail after pruning; the limbs will appear long and slender with a "puff" of foliage at the end. However, this creates an uneven weight distribution in the tree canopy. And when limb failure occurs, it is usually because all of the canopy weight has been moved to the end of the branches. Trees will often fall apart under their own weight even without a wind storm.

Tree Thinning Decreases Risk of Collapse

Property owners must understand that when a gust of wind pushes against a tree but cannot pass through the canopy easily, the chance of tree or limb failure increases. To minimize this problem, a tree needs to be properly thinned. The thinning process should be focused on the outer canopy of the tree. This will open up a sort of window in the tree that allows wind to pass through the canopy with less resistance. The thinning should involve no more than 25% of the living foliage with the interior foliage left intact.

Tree Structural Problems that Cause Collapse

Trees will often suffer from structural damages that are a result of leaning or decay, which can eventually lead to collapse. 

Leaning Trees

Trees lean for one of two reasons:

Phototropism - This is the bending of a plant (tree) toward the direction of more intense light (sunlight).A tree becomes top heavy as it becomes larger and then, because of its size or wet condition, root failure is likely to occur.

Armillaria mella on a treeA tree branch infected with Armillaria mellea

Root failure - Usually during prolonged wet conditions, the tree experiences loss of anchorage (roots holding onto the ground). The tree is in the process of falling but hasn’t reached the ground yet. This is sometimes more common with trees planted in lawn areas. Root disease is like a ticking time bomb because its activity is for the most part unseen, underground, and involves the part of the tree that keeps it in an upright position, the roots. Armillaria mellea or oak root fungus, is one of the most common root problems affecting trees, but luckily is something a certified arborist can usually identify. This root fungus decomposes the tree’s roots so that it may suddenly fall over on a clear windless day or wait to go down in a storm.

Sometimes there are outward signs of structural problems, such as conks at the base of a tree or a cavity eaten away by decay, which certified arborists can usually detect. Conks are the fruiting bodies of decay-causing fungi that are hidden out of sight within the trunk of a tree. The presence of mushrooms indicates there is dead organic material. Evidence of any of these should alert tree owners to a potential problem and appropriate action taken.

Fungi spreads more rapidly under certain atmospheric conditions. Take the California drought, for instance, which has caused great stress on trees throughout the state. This stress weakens the trees' ability to resist fungus, leading to a spread of fungal infection and disease. Check out our article on fungus caused by drought for more information. 

Tools for Identifying Hidden Decay

There are times when decay in trees is very difficult to identify due to the lack of visible or outward signs of its presence.  However, this problem will often make its presence known during a storm. Using certain tools, specialized arborists are able to identifying decay in trees that may not have shown any visible signs of having a problem.

Here are two specialized tools certified arborists use to detect decay:

  1. Resistograph: A special drill with a long small wire bit that is drilled into an area chosen by the technician to explore for decay. As the bit is drilled into the tree, it measures and records the resistance the drill encounters as it passes from solid wood into softer wood that has been compromised by decay. After a series of such inspections an arborist is able to provide his recommendations concerning how advanced the decay is and how to proceed.
  2. TreeRadar: One of the most recent advanced tools to measure wood decay. TreeRadar is a totally non-invasive to procedure done to the tree, using radar to provide a virtual image of the interior of a tree trunk, much the same as if one were to visit a doctor and receive an x-ray or MRI to evaluate his or her own health.

Tree Owner Responsibility

In spite of all of our advanced technology and expanded knowledge of trees, they will continue to collapse and fall. Society has accepted the risk of living among trees and, hopefully, the responsibility to care for them. When maintenance has been deferred or improperly performed, problems will arise.

Sometimes an arborist’s recommendations are ignored, and this can be a problem. Experts have an obligation to be forthright which means making judgments and recommendations that owners may not want to hear. Similarly, board members and managers have a responsibility to listen to an accurate assessment of a problem and act to remediate it.


Adapted from an article by Robert Booty, principal consultant for Arborist OnSite.™ He is an ISA Certified Arborist, member of the American Society of Consulting Arborists, and member of the ECHO Maintenance Resource Panel.

Photo attributions: Uprooted evergreen tree near Nettleton by Neil Theasby CC BY-SA 2.0, Lions Tailed by Ed GilmanA clump of honey fungus (Armillaria mellea) by ceridwen CC BY-SA 2.0.