Most trees don’t fall down unexpectedly. They send out distress signals for months, even years, but few of us notice. Unfortunately, these signals are not cries for help – a tree can’t tell you it’s feeling unwell. Instead, it may gradually increase its seed production, sacrifice a portion of its crown, or enlarge its sapwood. A tree’s distress signals are typically dismissed as nothing more than a bad year, poor soil, or bad genes.
The “V” in the canopy that isn’t just aesthetic
When two main stems compete for dominance, the one with the less acute angle typically weakens and becomes even more horizontal under heavy canopy wood, this is known as the weakest link theory.
Horizontal cracks and what they mean underneath
While vertical cracks might be common as the wood expands and contracts under changing load, horizontal cracks are not to be taken lightly. A seam running across the grain of the trunk is made as the tree tries to reinforce an internal fracture, essentially forming a rib around a hollow. These are not surface blemishes. They are evidence that the internal architecture has already shifted.
A simple test will tell you if this has happened where you can’t see it. Tap the trunk with a rubber mallet along its length. A hollow, resonant sound compared to the solid thud elsewhere tells you that the tree has been compromised.
Mushrooms aren’t decoration
Mushrooms and other fungal fruiting bodies are a sign of advanced decay in a tree’s root or buttress zone. Ignoring them can lead to disastrous consequences. But while we see the symptoms in miniature above ground, out of sight the fungus has already thrust a vast underground mycelial mat into the tree.
This conceals the real danger – a hazard tree. One gust too strong, one burst of heavy rain too intense and down she goes.
Got fungal fruiting bodies at ground level? Got to act fast.
The difference between a lean and a falling tree
There are two reasons trees lean. The first is phototropism: the tree has spent its life growing toward the light it needs to photosynthesize. It’s then compensated for that angle over the years. Trees like this usually appear to be healthy and are structurally sound. They have spent years adapting to their light source.
The second reason, the active lean, is the one you need to act on immediately. Simply look at the soil on the side opposite the lean. If the ground is cracking, mounding, or lifting, the root plate is already starting to lift. The tree isn’t growing that way. It’s falling that way, just very slowly.
This tree is in jeopardy of falling on its own and is the type of situation where you want to call a qualified GTS Trees arborist before the next wind event, not after. A formal climbing inspection or ultrasonic decay test can provide you with real data, not guesswork, of the tree’s condition.
What topping leaves behind
Cutting off the top of a tree may seem like a quick and easy way to reduce the size of the tree and avoid potential hazards, but the practice can have serious consequences for the health and longevity of the tree.
Topping, also known as stubbing, dehorning, or hat-racking, leaves the tree disfigured, more susceptible to disease and decay, and potentially dangerous in the long run. In many cases, the tree will need to be removed entirely.
The root flare you can’t see
You can see a healthy tree’s trunk widen just above the roots to form a root or butt flare. This flare that’s supposed to be at or slightly above the soil line and serves to physically stabilize the tree. Also, it allows the transport tissues that carry water and nutrients between the roots and the foliage to flare out.
When we bury that flare – by piling mulch against the trunk or by grade changes over time, we prevent the tree from being physically stable and from transporting water, nutrients, and sugars effectively between the roots and foliage.
This often results in the tree looking just fine for a while. Then it suddenly falls over.
A tree with a buried or girdling root flare may look healthy for decades or more. However, as the tree gets older and bears heavier wind loads or heavy foliage loads, you’ll see more dramatic failures.
Look at the base of the tree and see if it goes straight into the ground like a post. If you can’t see any widening at the base, that’s a clue the root flare may be compromised.
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