Wood chips are used as mulch and spread over the soil, surrounding plants. As the wood chips decompose, they add nutrients to the soil. The chips can also insulate the soil and prevent weeds from getting in and taking root. Wood chips are sold at garden and home improvement centers, although some communities offer free bags of wood chips that have come from local trees. Before applying wood chips to your landscaping, make sure that they do not contain anything dangerous or harmful to your plants.
Examine the wood chips for discoloration. Grab a handful of the wood chips and spread them out on a smooth surface. The color of the chips should be somewhat uniform, with slight differences -- for example, multiple shades of tan or brown. Any pieces with dark spots or green sections may be infected with mold that can spread to your plants. Discard them.
Look for yellowish patches growing on top of your mulched plant beds. This is slime mold and, although ugly, is not harmful to your plants. Spread out the affected mulch with a trowel or scoop it up and discard it with your yard waste.
Examine the bagged mulch for insects. Although extremely rare, termites can live in mulch and spread to your yard through it. Large ant colonies are much more common. Spot these insects by pouring out 5 to 6 inches of mulch and examining the mulch for insect movement. Seal the bag up and place it in direct sunlight for a week to kill any insects.