A blown down tree can crash through your roof, block the road, or even injure someone standing below. Removal of risky trees before they fall over is the ideal way to mitigate the danger.
1. Obvious Lean
Leaning is a major red flag that a tree may soon be blown down. The highest risk is when a tree has only recently developed a lean. In this case, it should be assessed by a tree service immediately to see if it can be saved with cabling to pull it upright, or if it will require removal. Trees that have leaned for years are likely not an immediate risk, but they should still be assessed regularly to make sure they are still stable.
2. Trunk Damage
Severe damage to the trunk weakens a tree, if it doesn't eventually kill it. Damaged trunks are also at higher risk of splintering in high winds or even under their own weight. Lightning strikes and previous storms are primary sources of trunk damage. Sometimes the damage originates from within via rot and fungal infections. Extensive bark damage can also weaken a tree and make it more likely to fall.
3. Crown Symmetry
A symmetrical crown looks better and it puts less stress on roots and trunk. When large branches or the bulk of the foliage is concentrated on one side of a tree, it becomes top-heavy and can begin to lean to that side. Eventually, the trunk may give up and split, sending the heavier half of the tree down. In other cases, wind may blow down the tree as the straining roots give out and can no longer support the asymmetrical crown. Pruning for symmetry solves the problem if it's done before damage occurs.
4. Churned Soil
Look at the ground around a big tree after a windy day. It should look more or less undisturbed. If it's churned up or if humps have raised in the lawn, then there was severe tree movement when the wind was blowing. Churning occurs when the roots begin to lift out of the soil, a sign that an eventual blow down is imminent. In most cases, removal is the safest option.
5. Leaf Dieback
Insects, disease, and drought can cause life-threatening injury to a tree. If the majority of the foliage and branches have died, then the roots are soon to follow. A prompt assessment by a tree service is necessary to determine whether the tree can be saved or if it should be removed before it weakens further.
Contact a tree removal service if you have concerns about one of your trees blowing down.