Q: Can a pile of wood chips burst into flame? My last three deliveries from the local tree guy smoked by day two and you could feel the heat radiating off the pile. When I went to spread them, there were huge pockets of nothing but black ash inside.

A: I guess that fits the facts: composting is just a slow type of oxidation, while fire is fast oxidation. The tree sap inside the pile fed fungi and bacteria, whose heat accelerated the normally glacial pace of wood chip decomposition.

I’ve never heard of a homeowner pile of wood chips bursting into flame but farmers are well aware of the danger of piling wet hay in a barn, where it can spontaneously combust.

On the other hand, see below

I wanted to confirm that wood chip piles can spontaneously burst into flames. My father has a farm in Fayetteville and he has given permission to several developers to unload their wood chips onto certain locations on his property.

On at least one occasion, one of the piles began to flame and then burst into a big fire. I too have seen where there is smoke billowing from the piles and you can feel the heat radiating from the pile.

Due to this occurrence, my dad now immediately disperses the piles as soon as he can to avoid any undesired fires.

Kathy W.

Walter’s note: I think it all depends on the size of the pile. Be cautious.