It’s not a common occurrence, but with a fairly dry spring and hot temperatures, mulch—in piles, in beds and even in flower pots--can spontaneously combust putting nearby structures in peril.

That was the case this spring in both Avon and Avon Lake, when two homes sustained damage due to mulch spontaneously combusting.

A fire May 27 at 33107 Northwood Circle in Avon Lake resulted after mulch in a flower pot heated to the point of setting itself on fire.

“There was enough mulch and heat in it  that the plastic pot caught on fire,” Avon Lake Fire Chief Glen Eisenhardt said of the incident, which was reported at 12:49 p.m.

While mulch fires aren’t rare, one resulting in an actual house fire is.

Eisenhardt said four pots had a mulch and humus mix and were close enough to the home that the siding on the west side of the house caught fire.

“The siding melted and two windows blew out,” Eisenhardt said, estimating damages at about $15,000.

He said neighbors used hoses to keep the fire under control until firefighters arrived.

Avon Fire Chief Frank Root III said his city dealt with a mulch fire last month that caused damage to a home at 39011 Bridle Court on April 24. 

“The damage was mostly to the deck and outside siding,” Root said. “Fortunately the homeowner was home (and reported it quickly).”

Both chiefs said dry weather could have contributed to the fires.

“If there’s a long period without rain, and the mulch is thick, it can start itself on fire,” Eisenhardt said.

Eisenhardt said mulch on hot blacktop can also result in mulch fires.

“Sometimes you’ll see someone putting water on a mulch pile to cool it down,” he said.

Eisenhardt recommended keeping pots with mulch away from houses  and both chiefs cautioned against using mulch to extinguish cigarettes.

“Sometimes there’s mulch fires on the side of the road, but that’s usually the result of someone throwing a cigarette out the window,” Root said.

Root also said older mulch, which is dehydrated, is more likely to catch on fire.

No injuries were sustained in either fire.