A Guide for New Yorkers: Understanding the Risks of Mulch Catching Fire

As the temperatures rise and the gardening season kicks into full swing, New Yorkers need to be aware of the potential risks associated with mulch catching fire.

Mulch fires can occur due to improper management or exposure to heat sources, and they have become increasingly common in recent years. Understanding the causes and taking precautionary measures can help prevent these unfortunate incidents.

What Causes Mulch to Catch Fire?

Mulch can generate heat that ignites a fire when it covers a large and compacted area or when it is piled up too thickly. Factors such as hot and dry weather, extended periods without rain, and strong winds contribute to the risk of mulch combustion.

Fire Chief Charles A. Moore, with over 40 years of experience in the fire service, tells Homes and Gardens that spontaneous combustion can occur when the depth of mulch and organic material is sufficient to decompose and generate its own heat. In some cases, external sources of ignition, such as cigarettes, grills, matches, or fireworks, can also cause mulch fires.

Flammable Mulch Materials to Avoid

Certain types of mulch are more flammable than others. Pine needles, cedar mulch, shredded bark, dry dead leaves, and wood chips are among the most combustible common mulching materials. Shredded rubber, while slower to spread flames, produces intense and large flames, and also emits a pungent odor. It is recommended to keep these hazardous mulches at least 30 feet away from homes to minimize the risk of fire.

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Preventing Mulch Fires

There are several things that New Yorkers can take to avoid mulch fires and protect their homes. First, consider using less flammable materials such as compost, leaf mold, or grass clippings from mowing the lawn.

When mulching flower beds or borders, avoid piling the mulch more than 2-4 inches thick as this reduces the risk of combustion. Fire Chief Charles A. Moore advises keeping the mulch moist and well-watered and ensuring it is placed away from combustible surfaces or the exterior of the home.