There are two types of mulch, inorganic and organic mulch. Rubber mulch and stome mulch are inorganic. These help prevent weeds, keeps the soil warmer during summer and cooler during winter. The pictures above are rubber mulch, the one below is wood mulch. Wood mulch is organic, when it breaks down it adds nutrients to the soil. Earthworms move this to the roots of your plants. Organic mulches keep soil cooler during summer and warmer during winter, also reducing the changes of temperature between nighttime and daytime.
