Firefighters suspect potting soil as possible cause of Aurora deck fire

AURORA, Colo. -- A woman was stunned after learning firefighters suspect her potting soil is to blame for a fire on her back patio. Experts believe it is possible fertilizer in very hot and dry soil combusted.

The combustion of potting soil fertilizer is so rare that most manufacturers don’t put warning labels on packaging. When the combustion happens, firefighters warn it can be very dangerous.

“I came home and saw the deck was on fire,” Nancy Osborne said. “No one had been home all day.”

Charred wood and crispy tomatoes were the only things left after the blaze damaged a corner of Osborne’s deck.

The plastic pot holding her tomato plant was melted and molded onto the deck. The fire is believed to have started inside the plastic container, which was pre-filled with soil, fertilizer and a tomato plant.

Osborne said she never thought the potted plant, purchased from The Home Depot, could be considered a fire hazard.

“There should be some kind of warning on these pots, that this can happen,” Osborne said.

Firefighters told Osborne a lack of adequate watering could have produced the perfect storm.

“[Firefighters] started telling me about the fertilizer and the combustible materials,” Osborne said. “[They told me] how with heat and dryness … it can combust.”

The fire happened Saturday when temperatures pushed to near 100 degrees.

When the mercury soars, it seems these fire scenarios are not out of the question. A quick search online shows reports of similar fertilizer fires in North America.

“[Firefighters] could find no other reason,” Osborne said. “They were pretty confident that this is what happened.”

Osborne said she will now water her plants daily and stick with ceramic pots instead of plastic.

Although fertilizer computation is a possibility, the Aurora Fire Department said no official cause will be determined because an official fire investigation will not be conducted. Fertilizer combustion is only a suspicion.