How to Spot a Hazardous Tree

Warning signs worth a closer look

None of these on their own means a tree must come out, but each is a reason to look harder — and several together, or any near a target like a house or driveway, is a reason to call.

• •Dead or dying branches in the crown, or a thinning canopy.
• •Cracks or splits in the trunk or major limbs.
• •Fungal growth (conks or mushrooms) on the bark or around the base.
• •A lean that is new, or soil heaving on one side of the base.
• •Roots that are damaged, rotted, or cut — often from nearby construction.
• •Hollows, cavities, or soft decayed areas in the trunk.
• •Bore holes, sawdust, or pitch tubes indicating insect activity.
• •Any branch touching or near a power line — do not approach this yourself.

When to call a professional

Anything involving power lines, a tree leaning over a structure, visible trunk decay, or a recent change in lean warrants a professional assessment rather than a wait-and-see. So does storm damage that has left a limb hung up in the canopy. These are exactly the situations where a tree that looks stable fails without much more warning, and where the cost of being wrong is high.