1. Excess canopy weight – When a tree’s canopy becomes dense and unbalanced, it acts like a sail in high winds. The larger the surface area, the more wind resistance the tree experiences. This increases pressure on both branches and roots.

The International Society of Arboriculture notes that proper pruning reduces wind resistance and improves structural integrity. Without maintenance, heavy limbs are more likely to snap under stress.

2. Long, extended limbs – Overgrown branches often stretch far beyond the tree’s natural structural support. These extended limbs are more vulnerable to:

• Wind whipping

• Ice accumulation

• Breakage at weak attachment points

The Penn State Extension explains that long, overextended limbs increase leverage during wind events, raising the likelihood of branch failure.

3. Weak branch unions – Trees that grow without corrective pruning may develop narrow branch angles or co-dominant leaders. These structural flaws are often hidden until a storm exposes them.

The University of Maryland Extension highlights weak branch unions as a common cause of splitting during storms. Once a major limb splits, the entire tree can become unstable.

4. Dense interior growth – When interior branches are never thinned, airflow through the canopy becomes restricted. This makes it harder for wind to pass through safely.

The Tree Care Industry Association notes that strategic thinning can reduce storm stress while preserving overall health. Dense trees trap wind rather than allowing it to move through naturally.

5. Root stress from canopy imbalance – Overgrown canopies do not just affect branches. They also increase strain on the root system. In saturated soil conditions, a heavy canopy combined with high winds can cause trees to uproot.

The Arbor Day Foundation explains that balanced pruning supports better root stability. When roots are already weakened by poor drainage or compaction, overgrowth compounds the risk.