Fire Concerns are Mulch Ado About Nothing

Dry wood. Hot sun. Little rain.

Alone, they may not amount to much. Together, there's potential for a bad turn of events.

According to the June 7 edition of the Naperville (Ill.) Sun, the fire department there had responded to 32 reports of mulch and landscaping material fires this year.

Does that mean everybody in the Southland should replace their mulch with decorative stones?

Not necessarily. But experts say anything is possible.

Mulch is organic material and can heat up as it decomposes, much like a compost pile, said Kevin Crowley, part owner of Cypress Landscaping in New Lenox.

Hot and drying materials potentially can catch fire, he said, but he hasn't heard of a rash of mulch fires in the Southland.

"I've never heard of any residential mulch fires in the area. Most mulch is only applied to a depth of two inches or so. That's not much," Crowley said.

However, he has heard of spontaneous combustion occurring in suppliers' yards where mulch piles can tower over a grown man.

"It does happen every once in a while at suppliers' depot areas where they bring it in and there's mounds and mounds of the stuff. Sitting for a long, long time, it starts to decompose, and things heat up when they decompose," Crowley said.

"So, yes, I've heard of those big piles starting on fire, but I've never heard of a fire in landscaping," said Crowley, who is in his 29th year in the landscaping business.

Dan Riordan, senior fire inspector for Tinley Park, has heard of mulch fires and said the conditions have to be just right.

"In general terms, anything is possible," Riordan said.

"Anything that is combustible needs the ignition source or the right chemistry to get it to start. I know we've had lots of mulch fires along the median in Harlem Avenue. With vehicles passing by, sparks from a discarded cigarette can easily ignite mulch," Riordan said.

That's not to say Tinley Park and other fire departments have been inundated with reports of mulch fires.

Crowley said he doubts most residential or commercial landscaping has enough mulch to pose a problem.

"I'd say most of those are two- to three-inches deep, and a couple of inches is not enough to cause a fire," Crowley said.

According to the Naperville Sun, authorities believe spontaneous combustion of mulch have may caused a fire that caused $175,000 of damage in northwest suburban Crystal Lake in April.

That's big, but Crowley is more concerned with preventing the fungus that sometimes pops up in mulch than of potential fires.

"In the summer, when it's hot and humid, fungus starts to grow. It looks like vomit. I tell people to gingerly pick it up with a shovel. You don't want to bust it up and get the spores everywhere. Lift it up and place it in a plastic bag. If you want to prevent it from growing, spray some fungicide on the mulch," Crowley said.

He also suggests raking the mulch now and then.

"It breaks it up, gets some air into the mulch and makes the mulch look better," he said.

Huber also liked the raking idea. "It does prevent the fungus from coming up," he said.

Of course, there's one more fire-safe solution, one the landscaping guys don't like: the afore-mentioned stones.

"In the past two or three years, some people are going back to using stone instead of mulch. Mulch, you have to replenish every year or two. Stone, you don't have to top it off," Crowley said.