How to Spot a Hazardous Tree Before It Falls
Most homeowners picture hazardous trees as obviously damaged—leaning precariously or covered in dead branches. But in reality, not all dangerous trees show such clear warning signs. Many hazards develop slowly and subtly, only becoming obvious once failure is imminent.
In Calgary, where strong winds, heavy snowfalls, and sudden chinooks regularly stress trees, understanding the early signs of risk is essential. By catching problems early, you can often save trees, avoid accidents, and prevent costly property damage.
Visible Warning Signs of Hazardous Trees
While some hazards are hidden, there are several red flags every homeowner should watch for:
Cracks in the Trunk – Vertical splits or cavities weaken a tree’s structure and may indicate internal decay.
Large Dead Branches – Deadwood is brittle and prone to falling during storms, especially in mature trees.
Fungal Growth at the Base – Mushrooms or conks often signal root or trunk decay, even if the canopy looks healthy.
Excessive Lean – A sudden or worsening lean suggests compromised root stability.
Out-of-Season Leaf or Needle Loss – Premature leaf drop, needle browning, or canopy thinning may reflect disease or environmental stress.
Canopy Dieback – Branches dying back from the tips inward often point to root or vascular issues.
Soil Heaving or Exposed Roots – Disturbed soil around the base can mean the root system is no longer anchoring the tree properly.
While these signs can help identify potential risks, they don’t always reveal the full story. A tree may appear outwardly healthy while hiding significant internal decay.
Why Hidden Hazards Are Dangerous
Some of the most hazardous trees in Calgary are those that look normal to the untrained eye. Internal rot, root damage, or poor branch unions may not show symptoms until the tree suddenly fails in a storm.
Because Calgary frequently experiences high winds and heavy snow loads, these hidden weaknesses can turn into emergencies overnight. Homeowners who rely on appearance alone often underestimate risks, leaving their property, family, and neighbors vulnerable.
Professional Tree Risk Assessments (TRAQ)
The most reliable way to determine if a tree is safe is through a Tree Risk Assessment performed by an ISA Certified Arborist with Tree Risk Assessment Qualification (TRAQ).
TRAQ assessments use a structured, science-based process to evaluate:
Tree Health – Examining bark, canopy density, root stability, and signs of decay.
Likelihood of Failure – Estimating the probability a branch, trunk, or entire tree may break or fall.
Consequences of Failure – Considering what could be damaged if the tree fails, including homes, vehicles, power lines, or people.
Risk Rating and Recommendations – Providing clear guidance on whether to retain, mitigate, or remove the tree.
This systematic approach removes guesswork and helps homeowners make informed, confident decisions.
Early Action Saves Trees—and Money
Catching hazards early doesn’t always mean removal. In fact, many trees can be saved with proactive care, such as:
Pruning – Removing hazardous branches while preserving healthy structure.
Cabling and Bracing – Installing supports to stabilize weak unions or heavy limbs.
Soil and Root Care – Improving drainage, reducing compaction, and supporting root health.
Targeted Treatments – Addressing diseases or pests that compromise tree health.
By addressing problems before they escalate, you not only preserve valuable shade and beauty but also avoid the far greater expense of emergency removals or property repairs.
The Cost of Ignoring Tree Hazards
Leaving questionable trees unchecked can lead to:
Emergency Removals – Far more expensive than scheduled pruning or mitigation.
Property Damage – Falling trees or branches can destroy roofs, fences, and vehicles.
Liability Risks – If a hazardous tree damages a neighbor’s property, you could be held financially responsible.
Loss of Property Value – Unsafe or neglected trees reduce curb appeal and resale potential.
Proactive care is always cheaper, safer, and less stressful than reacting to emergencies.
Why Hire an ISA Certified Arborist?
Tree risk assessment and hazard management are not DIY projects. An ISA Certified Arborist brings:
Training and Certification – Meeting international standards for tree biology, safety, and risk evaluation.
Specialized Tools – Using resistographs, soil probes, and climbing inspections to detect hidden decay.
Bylaw Knowledge – Ensuring compliance with Calgary’s tree regulations, including elm pruning restrictions.
Insurance Protection – Carrying liability insurance and workers’ compensation, protecting homeowners from risk.
Science-Based Guidance – Recommending preservation where possible, removal only when necessary.
This professional expertise ensures your trees are managed responsibly, safely, and legally.
The Bottom Line: Don’t Wait for a Storm
Hazardous trees don’t always announce themselves. Cracks, decay, or root issues may develop unnoticed until Calgary’s next windstorm or snowstorm makes them fail.
The safest way to protect your property and family is to schedule a Tree Risk Assessment with a TRAQ-qualified ISA Certified Arborist. Early intervention may save the tree, preserve property value, and prevent dangerous emergencies.
When it comes to tree safety, prevention is the best investment.
