Spontaneous combustion in mulch piles happens when heat, oxygen, and dryness combine under the right conditions.
Here’s how it works:
Decomposition Generates Heat: As bacteria break down organic materials like wood chips and bark, they release heat. In large piles, this heat gets trapped, creating a furnace-like effect.
Oxygen Fuels the Process: Mulch’s loose structure allows air to circulate, supplying oxygen to feed the heat buildup.
Dry Conditions Increase the Risk: During hot and arid weather, dry mulch is more susceptible to ignition.
The Result? A self-sustaining fire that can start without any external spark.