MADISON, Wis. -- Wisconsin gardeners could be harboring a fire hazard in their fall mums, according to state officials.

On Monday, the Wisconsin Department of Trade and Consumer Protection warned consumers that without the proper precautions, potted plants could create a fire, WISC-TV reported.

The potting soil that many people use to plant flowers and plants in containers is capable of catching fire, they said.

"Most people do not think of the soil in (plastic) pots as being something that may be flammable," said Jim Rabbit, a consumer protection director.

Rabbit said that potting soil is flammable and, in fact, not made up of dirt at all, WISC-TV reported.

Potting soil is typically made up mostly of peat moss, a brown fluffy material that, according to state consumer protection, is a fire risk.

Rabbit showed WISC-TV a plastic flower pot that had melted into a plastic picnic table after a planter of potting soil ignited in Sparta.

Ron Severson said that he came back from a week-long vacation to find not only his plant gone, but the planter and his table completely melted together on his deck.

Severson said that he found only a pile of ashes and a cigarette butt lying beneath the melted mess on the deck.

"It was a surprise," said Rabbit. "Like most people, we assumed that a pot full of dirt would not be a fire risk."

Rabbit said he and other consumer protection officials worry that a melting planter could ignite a wooden deck or table and create a disastrous fire.

Rabbit said his department conducted its own demonstration to test its concerns. He said that they lit some common potting soil on fire, and after only half a cigarette burned on top, each pot began smoking and burned for hours, even after the cigarette was removed.

Longtime firefighter and greenhouse owner Gary Johannssen said that he was surprised by the news.

"It's a new one for me so definitely," said Johannssen. "You know, whenever you see baskets or pots around, you do see cigarette butts in them and nine out of 10 times, there's not going to be any soil in that pot. It's going to be peat moss which will burn," said Johannsen.

State officials said the problem doesn't merit a product recall because the product isn't at fault. It's a set of circumstances coming together to produce a possible fire threat, they said.

Johanssen said it would probably take two or three days without rain or watering for a potted plant to become dry enough to possibly ignite, WISC-TV reported.