Most trees are safe, but some develop problems that make them a genuine risk to people and property. Knowing what to look for can help you catch a hazard before it causes damage. Here are five signs worth taking seriously.

1. A New or Worsening Lean

A slight, long-standing lean is often normal. A lean that’s new, increasing, or accompanied by soil lifting on one side of the trunk can signal root failure or instability, especially after heavy rain or wind.

2. Cracks or Splits in the Trunk

Vertical cracks, seams, or splits in the trunk can indicate internal decay or structural weakness. Cracks are especially concerning if they run deep or appear to be widening over time.

3. Large Dead or Broken Branches

Dead branches, especially large ones high in the canopy, can fail without warning, even on days with no wind. “Widowmakers” (hanging or partially broken branches caught in the canopy) are a serious hazard and should be addressed promptly.

4. Fungal Growth at the Base

Mushrooms, conks, or fungal brackets growing at the base of the trunk or on major roots often indicate internal decay. Not every fungus means a tree is failing, but it’s a strong signal that a professional assessment is warranted.

5. Root Damage or Exposed, Cut Roots

Construction work, trenching, or grade changes near a tree can sever roots that provide structural support. A tree that has lost a significant portion of its root system, even if the canopy still looks healthy, can become unstable.

What to Do Next

If you notice any of these signs, especially on a large tree near a home, driveway, or area where people spend time, don’t wait. A certified arborist can assess the tree’s risk level and recommend whether pruning, cabling, or removal is the right next step.

Emerald Arbor Care offers tree risk assessments throughout Seattle and the Puget Sound region. Call (206) 558-2814 for a free evaluation.