Mulch has many positive attributes in residential landscaping. It reduces the water requirements of plants, cools the soil temperature, controls weeds and soil erosion, and visually enhances the landscape. But a major drawback is that many are combustible, which presents a huge problem in fire prone areas. Embers from an approaching wildfire can ignite areas where mulch is used. If these areas are adjacent to the home, it could be wind up to be a disastrous mix.
An evaluation of mulch combustibility was performed in 2008 by the University of California Cooperative Extension and the University of Nevada Cooperative Extension. The results from this project offer recommendations for uses of mulches in wildfire hazard areas.