How to Tell If a Tree Is Dangerous — Visual Inspection Guide

Across Burlington County and South Jersey, trees silently develop hazardous conditions for months or years before failing. Learning to recognize the visual warning signs of a dangerous tree can save your home — or your life. This guide covers the key indicators to look for during a basic walk-around inspection of your property.

Step 1: Look at the Overall Tree Form

Start from a distance to evaluate the tree's overall silhouette and form. A healthy tree has a full, symmetrical canopy relative to its species. Look for: significant asymmetry in the crown (may indicate root or vascular failure on one side), a pronounced lean that has recently changed, large sections of dead canopy (gray/brown while surrounding trees are leafed out), or a crown that appears sparse compared to similar nearby trees.

Step 2: Inspect the Trunk

Walk around the entire circumference of the trunk and look for: cracks or splits running vertically along the bark (may or may not be visible through the outer bark), soft or spongy wood areas (press gently — healthy wood is firm), missing bark panels exposing bare wood, swelling or bulging on one side of the trunk (indicates internal decay or reaction wood), and cavities or holes large enough to insert your hand.

Step 3: Check for Fungal Growth

Conks, mushrooms, and bracket fungi growing from the trunk base, along roots, or from major limbs indicate internal wood decay. Note the location: fungi at the trunk base typically signal root and butt rot (most dangerous structurally), while fungi high on the trunk indicate heart rot. Either condition warrants professional assessment, especially if the tree is within falling distance of a target.

Step 4: Examine the Root Zone

Inspect the ground around the base of the tree out to a radius equal to the tree's height. Look for: soil cracking or heaving on the windward side of the tree (root plate lifting), severed surface roots from previous construction or landscaping, areas of dead grass or soil over shallow roots (may indicate root decay), and mushrooms growing at the soil surface around the root zone.

Step 5: Assess the Branch Structure

Look up into the canopy. Identify: dead branches — easy to spot in summer as leafless sections among living foliage; hanging or broken branches wedged in the canopy (called "hangers" or "widow makers"); large branches with sharp V-shaped crotches packed with bark (included bark unions — extremely prone to splitting); and cracks or splits at major branch unions.

The Target Assessment: Is Anyone at Risk?

A tree's hazard rating depends not just on its condition but on what's at risk if it fails. A dead tree in an open field is low risk. The same tree over your home is high risk. When evaluating a potentially dangerous tree, identify "targets" within the fall zone: buildings, vehicles, play equipment, frequently used outdoor areas, utility lines, and neighboring properties.

What Professional Arborists See That You Don't

Licensed arborists use resistograph drills to measure internal wood density, sonic tomography to map decay zones inside trunks, root excavation to inspect subsurface root health, and aerial inspection from lifts to assess the upper canopy. These tools reveal internal conditions invisible to the naked eye. If your visual inspection raises any concerns — or if the tree is large or located near structures — a professional assessment is strongly recommended.

When to Call Jimmy's Tree Experts Immediately

• Any crack, split, or large wound on the main trunk
• Fungal growth at the trunk base
• Root plate lifting (soil heaving near the base)
• Major hanging or broken branches
• Sudden lean change — any amount
• Dead tree within falling distance of any structure or living area

Jimmy's Tree Experts LLC is NJ Board of Tree Experts licensed (NJTC 939824) and available 24/7 for emergency tree hazard assessment and removal throughout Burlington County, Camden County, Gloucester County, Mercer County, and South Jersey. Call (609) 556-3010 — don't wait until a dangerous tree becomes a disaster.