A hollow tree could be dangerous and must be pruned or removed, or it could be naturally hollow and you don’t need to do anything. But how to know if your hollow tree is dangerous or harmless? You can use this guide to know this. To be sure, consult arborist services for a tree assessment.
Why Trees Become Hollow?
Various Factors can affect trees, creating cavities in their trunk:
Fungal Decay
Fungal decay is a common cause of a hollow tree. When fungi enter a tree through an entry, a wound caused by a broken bark, storm damage, animal damage, etc., it feeds on the wood. This reduces the wooden mass around the hole and the cavity grows.
Broken Branches
Broken branches are also an individual cause of a hollow tree. If large branches fall due to any reason, and if the wound left by the branch is difficult for the tree to heal, it can further lead to decay and create a hollow trunk.
External Damage
Storm, lightning, animal damage, a vehicle striking the tree, improper pruning, fire damage, or other external factors can create a small hole or wound in a tree. After that, fungi, insects, birds, small mammals, etc., can gradually weaken the area, leading to a bigger cavity.
Old Tree
Many old trees develop a cavity in the trunk due to gradual decay. They may still be healthy because trees use the layer just beneath the outer layer for transporting nutrients to all of their parts, not the internal wood (heartwood).
Signs A Hollow Tree Is Dangerous
More Than 1/3 Of The Trunk’s Radius Is Hollow
If you notice that more than 1/3 or 33% of the trunk’s radius is empty or hollow, the tree could be hazardous. As stated before, a tree requires its layer just beneath the outermost layer to transport nutrients. If the hollowness or decay is extensive and eats up that layer as well, the tree may become weak and unstable.
Hollow-Sounding Wood
This is a simple test you can do to determine if a hollow tree is dangerous or not. Use a rubber mallet or a small stick. Tap it on the trunk near the hollow area and other parts of the trunk.
A hollow-sounding wood means that there is internal decay, and the tree is distressed and can fall. But if the sound is sharper and wood-like, the hollow trunk should not be a big concern.
Soft, Spongy, Or Bulgy Trunk
This is a huge sign of internal decay. If you notice softness, sponginess, or bulginess, or sunken areas on the trunk, take it seriously and consult an expert.
Bigger Cracks And Splits
Small cracks are not concerning as they are common on tree trunks. However, if you see bigger, vertical cracks and splits, and cracks near large branches, it may signal decay and distress. A hollow tree with big cracks and splits is dangerous because they show weakness. A storm or wind can cause the tree to fall suddenly without any notice.
Falling Branches
Although minor branches falling occasionally doesn’t mean a problem in trees, if larger branches are falling, especially from the upper canopy, it may be a sign of a hazardous tree. There may be internal decay affecting the tree’s health.
Root Damage Or Hollow Trunk Near The Base
The concern for a cavity in the tree trunk increases with its proximity to the base of the tree. The closer it is to the base, the more dangerous the tree is. This is due to the decay affecting the roots. As roots play a major role in keeping a tree stable, decaying roots will weaken the tree, and the tree can fall at any time.
The Region Receives A Higher Number Of Storms
If your region receives a lot of storms or gusty winds, leaving a hollow tree without any support or not removing it can prove to be a mistake. So, if you have a hollow tree and there is a major storm waning, consult tree removal services Chevy Chase to cut down the tree.
Mushroom Growth Around The Base Of The Tree
Visible mushrooms near the base of a tree indicate extensive decay and fungal growth. This is a sign that the tree is not healthy and could be dying, and can fall without any notice.
Leaning Tree
A leaning tree means trouble in most cases, even though not every leaning tree is going to fall. However, if you have a hollow tree leaning towards one end, you should consult an arborist immediately.
The Tree Is Near The House, A High Traffic Area, Or Power Lines
Even if you don’t notice any signs of a dangerous hollow tree, don’t skip a consultation with a tree expert if the tree is near the house, any high traffic area, power lines, a street, or any other important area, which can lead to property damage or injuries if the tree falls.
Signs A Hollow Tree Is Most Probably Harmless
No Leaning
As leaning shows stability problems, if there is no leaning, the tree may be fine. However, make sure it doesn’t have other signs of a dangerous hollow tree.
Thick Trunk
When you tap the trunk, you hear a sharp wood-like sound, not a hollow sound. Moreover, the trunk’s outer layer is thick and healthy. There are no soft, spongy, or bulgy areas.
Small Cavity
The hollow opening is less than 1/3 of the trunk’s radius. Moreover, the cavity is dry and the area around it is thick.
No Falling Branches
The canopy of the tree is healthy and all major branches are intact.
No Cracks Or Splits
Apart from shallow cracks, there are no deep or vertical cracks or splits.
Things Not To Do With A Hollow Tree
Don’t Fill The Cavity
Avoid filling the cavity with bricks, cement, expanding foam, or anything else. This will block moisture from evaporating and will speed up decay or whatever disease the tree is suffering from. This will also restrict the tree’s natural healing process.
Similarly, avoid painting, spraying, or using waterproof coating on the hollow area.
Avoid Mulching Excessively
Mulching is a good practice for protecting a hollow tree, but you should only mulch around the base of the tree. There should not be mulch piled against the tree trunk, as this will only trap moisture and speed up decay.
Don’t Prune Large Branches
Some people think that pruning large branches will reduce the weight on the tree, but it only backfires because large branches are essential parts of a tree. Cutting them can create wounds and fungi or insect infestation.
Don’t Make Drainage Holes
An old method of removing water from hollow trees was making drainage holes. This method is not suggested today in most cases. Avoid drilling drainage holes unless a licensed arborist suggests.
Conclusion
A hollow tree may or may not be dangerous. So, look for the above-mentioned signs. If you notice signs of a dangerous hollow tree, call in emergency tree services Kensington immediately. An expert will assess the health of the tree and suggest support systems or other methods to save the tree. But if the tree’s health is deteriorating, they may suggest removing the tree.