Mulching is one of the most beneficial practices a homeowner can use for better tree health. Mulches are materials placed over the soil surface to maintain moisture and improve soil conditions. However, improper mulching materials and practices may have little, or even negative, impact on the trees in your landscape. Benefits of Proper Mulching:  Helps reduce soil moisture loss through evaporation  Helps control weed germination and growth  Insulates soil, protecting roots from extreme summer and winter temperatures  Can improve soil biology, aeration, structure (aggregation of soil particles), and drainage over time  Can improve soil fertility as certain mulch types decompose (Tips courtesy: