In Illinois, the Naperville Fire Department has responded to 32 mulch and landscaping material fires since Jan. 1, compared to 22 during the same period in 2006, according to Assistant Fire Chief Michael Zywanski.

Because of the growing numbers of landscaping material-related fires, the city of Naperville and the Naperville Fire Department have started cautioning residents about the potential hazards of the seemingly harmless wood debris.

Zywanski speculated that the increase in mulch fires is due in part to the climate, which had been particularly dry and windy earlier this spring, and had reduced the moisture content of the mulch.

Mulch fires are especially dangerous because the flammable material tends to border homes and other structures. Zywanski said many of the reports have come from commercial properties and office buildings where a greater number of people are smoking and discarding still-smoldering cigarettes.

Another risk factor is perhaps less obvious. Doug Krage, 47, who owns Naperville Mulch Sales, said it is possible for a large pile of mulch to spontaneously combust.

Perhaps the best-know incident in the Chicago-land area occurred April 23, when the garage and attic of a home in Crystal Lake were set ablaze by what authorities believe was a spontaneous combustion of mulch. The fire caused a reported $175,000 worth of damage.

?EUR??,,????'??Mulch is organic matter, so when it decomposed, the chemical reaction gives off heat,?EUR??,,????'?? Krage said. ?EUR??,,????'??If a pile was left to decompose, it could get hotter and hotter, and potentially cause a fire.?EUR??,,????'??

But Krage said spontaneous mulch combustion is not something he warns clients about, since it is unlikely to occur unless the pile is very large.

But Zywanski believes that one can never be too careful when dealing with what is essentially decorative kindling. He advises that landscapers and property owners take precautions with mulch at any depth and should, above all, not smoke anywhere near the stuff.

?EUR??,,????'??It?EUR??,,????'???s just asking for trouble,?EUR??,,????'?? he said.