Holdover Fires
Ways to manage and mitigate this increasingly common wildfire threat.
A Sleeping Giant
Understanding the Root Causes
A holdover fire appears extinguished but continues to smoulder deep underground.
A holdover fire (often called a "zombie fire") is a fire that appears extinguished but continues to smoulder deep underground.
Holdover fires are notorious for surviving through the winter and "roaring back to life" once the snow melts and the spring winds arrive. This is an increasingly common wildfire threat for Alberta producers.
Why do holdover fires happen?
Recent extended droughts and a warming climate have created exceptionally dry conditions. Research suggests these fires are sustained by:
Carbon-rich Peat: Smouldering in thick layers of organic soil beneath the snow.
Woody Root Systems: Fires can follow tree roots deep into the earth, where they stay insulated from the cold.
When the ground thaws and dry grasses are uncovered, even a little wind can ignite these smouldering embers into an open flame.
Best Burning Practice #1
Winter Burning: The Right Way
Winter is the safest time for permitted burning because the ground is frozen and snow-covered. However, safety depends on preparation:
- Plan with a Pro: Always consult your local Fire Guardian before you light a match.
- Location Matters: Avoid building piles on muskeg or peat moss, which can carry fire underground.
- Build "Clean" Piles: Construct piles that are tall, tight, and dirt-free. Soil mixed into a pile creates pockets where embers can smoulder for months; dirt-free piles burn hotter and more completely.
Best Burning Practice #2
Spring Check-Up: Avoiding the Resurgence
Before the spring thaw, you must revisit every site where you burned during the winter. Follow these steps to ensure the fire is truly dead:
- Probe the Ground: Use a metal rod to feel for heat deep below the surface.
- Roll and Stir: Turn over any remaining debris and "roll" the pile to expose the base.
- The "Hand Test": Carefully check for hot spots. If it's too hot to touch, it’s too hot to leave.
- Water it Down: Soak any hot spots while stirring the debris until the area is cool to the touch.
- Monitor the Wind: Keep a close eye on your burn sites during the first high-wind days of spring.
The Farm FireSmart Way
maintaining your own property is your first line of defense
Proactive Maintenance
The 1.5m Zone
Maintain a non-combustible perimeter (gravel, dirt, or concrete) immediately around your structures.
Clean the Gutters
Remove dead leaves and pine needles from rooflines and gutters.
Prune and Thin
Trim tree branches within 2 meters of the ground.
Clearance Zones
Move firewood and combustible furniture at least 10 meters from buildings. Maintain 30 meters of clearance from grasslands and 100 meters from woodlands.
Screen the Vents
Cover exterior vents with 1/8” or 1/16” wire mesh to prevent embers from entering your home.
If a Wildfire Approaches
Visibility
Turn on all interior and exterior lights so firefighters can see your home through the smoke.
Seal the House
Close all windows and doors (including interior ones) to slow the spread of fire.
Hydrate
Connect garden hoses to faucets; if time permits, place sprinklers on the roof.
Evacuate
Follow all government orders immediately. Ensure you have a written evacuation plan ready.
Landowner Liability
The Responsibility Lies With You
As a landowner, the responsibility for a fire begins and ends with you.
- You are liable: If a fire escapes your control—or even if a winter holdover fire restarts on your property—you may be responsible for the full costs of containment and extinguishment.
- Insurance: Speak with your broker to ensure you have adequate wildland fire insurance coverage.
- Permits: Always have your Fire Permit on hand. If you re-pile or start a new burn, you must obtain a new permit.
