Potting Soil Fires and Your Safety

During this past year, the Colorado Springs Fire Department has investigated several fires caused by potting soil. In fact, just this year alone our community has suffered property losses in excess of 3 million dollars due to potting soil fires. Here are some unique factors to take into consideration.

Many potting soil mixes on the market today contain as much or more organic material as inorganic material. For example, potting soil can be made of shredded wood, bark, and/or peat moss with minimal amounts of what we call real soil (dirt). Styrofoam pellets, perlite and vermiculite are some of the other items that are often added to the soil mixture for aeration and water retention. In addition, many mixtures also include different types of fertilizers. Some fertilizers are oxidizers, which will make a fire that does start, grow at an even faster rate.

Potting soil mixtures are shipped moist and in plastic bags from the manufacturer. Most people use the soil in their planters in the Spring, then they forget about them once Fall/Winter arrives. Bacterial decomposition occurs within the mix that creates heat. This is the same principle that makes compost piles or bales of hay heat up. Although this principle, which is called spontaneous combustion, is usually found more often in climates containing more moisture; because water acts as a catalyst, these types of fires can also occur here.

As evidenced this past year fires can start when you use the old potting soil as an ashtray. You may think you are putting your cigarette out into “dirt”, when in fact you are creating an opportunity for fire. So the question to ask is, “Have you taken the proper precautions with the planter pots in and around your home to keep your family and property safe?”

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