The answer to this question depends on several factors, including the type of mulch and the condition of the soil. In general, grass will not grow through most types of forestry mulch. However, if there is a lot of organic material in the mulch, it may be possible for grass to grow through it. Cut trees will not grow back through forestry mulch. These rules apply to mulching with the following types of forestry materials: Wood chips, Grass clippings, Bark chips, or woody debris from trees that died naturally (for example, a dead tree in your yard) It is also important to know the type of soil you are working in.