Temperature control:  Mulches insulate plants from drastic temperature changes.

Attractive appearance:  Mulches provide a neat, uniform look to your landscaping.

Moisture retention:  Mulches reduce the speed of water evaporation while keeping an even supply of water on the upper levels of the soil.

Prevention of compaction:  Mulches break the fall of water drops, which can cause the soil to compact and inhibit plant growth.

Soil texture improvement:  The soil underneath the mulch benefits as well for example, clay soils get improved aeration, and sandy soils retain water better.