How to Tell if Your Trees are Safe!

Hazardous trees suffering from decay and weakness pose a danger to people and their property. Every year homeowners experience losses from fallen, uprooted, split, and decayed trees. Over the past 50 years, as a world-renown Arborist and tree exert, I’ve developed a simple guide to help homeowners save trees from removal by recognizing the symptoms of tree decay early. This guide will help homeowners determine if their trees are healthy and safe.

Beautiful, Safe, and Healthy Trees in New Jersey

How Does Tree Decay Start?

Most trees are safe. Understanding how trees grow and the process of how a healthy tree can develop hairline cracks that can lead to air and moisture finding their way past the cambium layer, into the hardwood; internal decay is usually the result. Recognizing superficial healing tissues is camouflaging the rot inside.


Open wounds, cavities, and splits are often occupied by bees, squirrels, birds, and even raccoons. First, there is decay, and all these critters mentioned above look for a hiding place to get away from bright lights, cold, draft, and noise. They often raise their young in these hiding places. When these cavities are too deep and too extensive, it would be better to have these trees removed. Holes near the soil often harbor termites and carpenter ants. Since moisture promotes decay, the presence of insects and fungus infections certainly have a detrimental effect on the structure of a tree. Painting of wounds with a tree wound dressing and installation of cement or fiberglass fillings have been questioned by Alex Shigo, a scientist from the University of New Hampshire. They have been abolished after extensive research has been done on both methods. The painting of wounds has blocked oxygen from promoting cell growth in wounded areas, and the cement and fiberglass fillings in tree cavities have not stopped the decay enough to expect any internal healing resulting from it.

If you see vertical splits in a scar that is not covered by bark, it is not alarming. If you see a horizontal crack in an identical tree wound, you have to be alarmed, because you have an internal fracture, which could be considered a hazardous condition.

New Jersey Residents Check Your Pear Trees

In New Jersey, an Asian import, the Bradford Callery pear tree is on the top of the list of frequently splitting trees. By the time they are 70 feet high and four feet in diameter, they have done untold damage, and many homeowners have them removed before they fall on power lines, houses, cars, etc. During new construction, often tree trunks get injured, roots get damaged, the water table changes and the trees are exposed to new factors which they were never exposed to before. Injuries to trees during construction can show up 20 years later. Deep-root feeding every three years with 10–6–4 50% organic nitrogen is suggested to help these trees to recuperate and hopefully get well again.

At the base of fragile trees, sometimes shoestring-like fungus strands develop; they are black in color. The botanical name is Amarilla mela. The sight of such fungus strands indicates that a lot of damage has been done to the roots and the base of that tree. Since the damage is irreversible, trees infected by this fungus can become unstable due to the loss of roots. Flat headed mushrooms are also a sign indicating a weak root system.

Yes, it’s true, the tree can have genetic defects. V crotches are joints in trees that are considered genetic defects. They have no connecting tissues to keep a double or multiple trunk formation from splitting. Water is usually seeping into the separations of a V crotch and rot begins, which cannot be controlled and is the reason why many trees split. The splitting can happen without any provocation like wind, ice, old age, etc. Heavy-duty galvanized cables or steel rods can be installed to ensure that these multi-trunk trees will not split and cause damage.

If you see distortion on the tree trunk within your reach, you can spot a hollow trunk by testing the density of wood by listening to the hammer strokes you check the trunk with. If it has a high pitched sound, the trunk seems to be reasonably stable. If the strokes sound like you are hitting a cardboard box, you have good reason to doubt the stability of the base of the tree.

Healthy Trees in a New Jersey Park


Examining your trees yearly will not only help you maintain beautiful, healthy trees but keep people safe and your property from experiencing losses due to damage from fall branches and trees. I hope you find this guide useful and it helps you keep the planet green.



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Martin Schmiede

Martin Schmiede

Martin Schmiede is an arborist and author who lives and works in the Westfield, New Jersey area. He loves saving trees and keeping the planet green.