The Surprising Way Your Potting Soil May Be A Fire Risk

When placing planters and pots in your garden, there are many steps to take to ensure your plants stay healthy. One key factor is the type of potting soil you use. From nutrient content and plant matter to added fertilizers and moisture-control ingredients, the right soil you choose varies between individual plant needs. There are also key differences in potting soil vs. potting mix to consider, even though the terms are often used interchangeably. While you might be concerned about getting the right kind of soil for your potted plants, the possibility of the soil catching fire is likely not something you worry about. Nevertheless, this is a real concern that may be brought on by a variety of internal and external factors that impact the potting soil.

Contrary to the name, most potting soils do not contain actual soil at all. These commercial products cannot technically be classified as soil because they lack minerals and decomposed plant matter (humus). Instead, most of the potting "soils" you find on the market are actually soil-free potting mixes that are likely to include a mixture of vermiculite, perlite, peat moss, and pine bark. It is these ingredients, not actual soil, that could cause a potential fire hazard under certain circumstances. On the flipside, some potting soils do contain actual soil, but these products are not as well-draining and not suitable for potted plants.

Most potting soil mixes have ingredients that can be considered flammable. Among these are the aforementioned pine bark and vermiculite as well as other materials, such as coconut husks and other types of wood particles. If your potting soil mix is exposed to flames or extreme heat, it has the chance of catching fire. It will not, however, automatically combust in a hot and dry environment on its own.

While perhaps not considered the biggest problem with container gardening people think of, the potential fire risk of commercial potting soil mixes is still worth watching out for. This is especially the case if you live in an extremely dry and hot climate where fires are more likely to develop. Keeping your potted plants watered and maintaining moist soil may help remedy this problem. Also, you might consider keeping plants with potting soil mixes away from any fire sources in your yard, including candles, smokers, and fire pits. Moving potted plants away from flammable objects could prevent a fire from spreading.

Using potting soil appropriately is important. For example, one common mistake that increases the risk of fires is to use soil-containing pots and planters as ashtrays. The cigarette butts can get hot enough to ignite some of the ingredients in the potting mix. For outdoor plants, make sure the potting mix is intended for outside use to keep it from drying out faster than normal. Gardening with terracotta pots can also provide extra protection against fires because they help contain the fire better than other materials.