Many trees naturally develop a bit of a lean as they grow, stretching and bending around other trees or structures to capture the maximum amount of sunlight (a process known as phototropism). In several cases, a slight lean in a tree is perfectly normal and not something you need to worry about.
However, if you notice that your tree has developed a more dramatic lean in a short amount of time, you’ll want to take action quickly, as the change in structure could be a sign of instability. In instances like this, your first step should be to contact your local arborist, who can evaluate the tree’s condition and determine if it needs additional support or even removal for safety reasons.
When a Leaning Tree Is Cause for Concern
So, how do you tell the difference between a tree with a harmless personality quirk and one that presents a genuine hazard? While a sudden change is the strongest indicator of a problem, there are several other signs that should prompt a call to an ISA-certified arborist.
Heaving Soil and Exposed Roots
Take a close look at the ground on the side opposite of your tree’s lean. Is the soil cracking, lifting, or mounding up? Can you see exposed roots that weren’t visible before? These are critical signs that the root plate is beginning to lift and fail. The tree may be moments away from losing its grip on the ground and could topple over, especially if there’s a storm or high winds.
Cracks and Splits
Pay close attention to the trunk, especially near the base. Look for deep, vertical cracks. Cracks that appear on the side the tree is leaning toward can indicate that the wood fibers are buckling under immense pressure. Conversely, cracks on the side opposite of the lean suggest the fibers are being stretched to their breaking point. Both cases are serious.
Decay on the Trunk
Also, keep an eye out for cavities, hollows, areas with peeling or missing bark, and fungi, such as mushrooms or shelf-like conks growing on the trunk or near the base. These could all point to the fact that your tree is leaning due to internal rot. As the decay spreads throughout the tree, it will turn strong wood into a soft, spongy material that can no longer support the tree’s weight.
How to Fix a Leaning Tree
If an arborist determines that your leaning tree can be saved, there are several techniques they might recommend to provide support and mitigate the risk. The appropriate method depends on the tree’s size, age, species, and specific reasoning for leaning. The three most popular options for fixing a leaning tree are pruning, cabling, and bracing.
Pruning to Reduce Weight
In some cases, a tree’s canopy is simply too dense for its trunk to support, especially if it’s one of those trees that has a natural lean in the first place. In these instances, a certified arborist can perform structural pruning to reduce the weight on the leaning side of the tree.
Proper pruning can also reduce the sail effect, where a dense canopy catches the wind like a sail on a ship, putting immense strain on the trunk and roots. When limbs are strategically removed according to ANSI A300 standards, the tree’s weight is redistributed, making it more stable and encouraging it to grow in a more upright direction.
Cabling for Additional Support
For larger, more mature trees where the primary issue is weak or overextended limbs, cabling can be an effective solution. While it doesn’t straighten the tree, it prevents further leaning and adds stability during storms.
When cabling a leaning tree with weak or long limbs, the arborist installs high-strength steel cables in the upper two-thirds of the tree’s crown. The cables are attached to different limbs, typically in a triangular pattern, to provide extra support and redistribute the load. This prevents individual limbs from splitting or breaking off, which could exacerbate the tree’s lean or cause significant damage if they fall.
Bracing to Strengthen Weak Points
While cabling supports the limbs, bracing is used to reinforce the trunk itself. If a tree has developed a deep crack or split in its main trunk or at a major fork (where large branches diverge), an arborist can install threaded steel rods, called brace rods, through the trunk. These rods are secured with nuts and washers on either side, effectively bolting the weakened sections together.
Bracing provides rigid support and prevents the crack from spreading further, which could cause the tree to split apart completely. This method of tree care is often used in conjunction with cabling to provide a comprehensive support system for a tree with significant structural issues. Together, these systems help the tree bear its own weight and withstand environmental stresses more effectively.
When to Consider Removal for an Unstable Tree
Unfortunately, not every leaning tree can be saved. In some instances, the risk to people and property is simply too great, and removal is the only responsible option.
An ISA-certified arborist will often recommend removal if:
- There’s Severe Root Damage: If the root system has failed and the tree can no longer anchor itself, it’s unsafe to leave the unstable tree standing.
- There Are Significant Structural Cracks: Deep splits in the trunk may be too severe for bracing.
- The Tree Is Too Close to Structures: A large tree leaning toward a home, garage, or power lines poses unacceptable risk.
- The Tree’s Overall Health Is Poor: If the tree is diseased, decayed, or infested, the lean is unlikely to be corrected successfully.
- The Tree Has Suffered From Storm Damage: Trees that are uprooted or partially toppled during a storm are often beyond saving.
Help Your Tree Stand Tall!
Do you need help with a leaning tree on your property? While navigating the health and safety of your trees can be a complex and stressful process, you don’t have to do it alone. The professionals at Blue Pine Works are here to help.
Our team is led by an ISA Board-Certified Master Arborist with over 15 years of proven experience in assessing and managing all types of tree-related challenges. We can accurately determine if your tree’s lean is a harmless quirk or a serious hazard and recommend the most effective and safest course of action, whether it’s pruning, installing a support system, tree removal, or other plant health care solutions.
Contact Blue Pine Works today for a professional consultation and gain the peace of mind that comes with knowing your property is in expert hands.