Potted plants are a great way to improve outdoor space and add color to a balcony or patio.  However, many people do not realize the latent fire hazard that potted plants pose.  In fact, we learned of this issue last summer when a fire that started in a potted plant on a second floor wood balcony.

Contrary to popular belief, potting soil does not really contain much actual soil.  The potting mixture available in most stores is a blend of aged, composted wood and bark, mixed with elements such as peat moss, Styrofoam, and other chemicals.  Further, many potting mixtures have fertilizers included as well.  The purpose of these potting mixtures is to aerate and retain water inside the pot, not to resemble the dirt that ground plants live in.  While the potting mix is successful in its goal of promoting plant life inside the pot, the mixture of chemicals and wood products tends to become very flammable as the mixture dries out over time.

Many potted plant fires are started accidentally.  Last summer’s fire started when a visitor to the unit used the potted plant to extinguish a lit cigarette.  Many people assume that pushing a cigarette into the potting mixture is akin to using a sand ashtray or throwing the cigarette on the ground; they do not realize the composition of the potting mixture is flammable and therefore dangerous.

A few precautionary measures that will help reduce the risk of potted plant fires.  First, make certain that owners are aware of this risk and do not use potted plants as ashtrays.  Also, remind owners and residents to throw away old potted plants that have dried out.  The potting mixture decomposes over time which produces bacteria, and under certain conditions it can produce heat and spontaneously combust into a fire.  Finally, if you do permit potted plants on balconies or patios, require clay pots.  Not only do you score design points, but a clay pot will contain a fire much more successfully than a plastic pot.