In addition to the aesthetic appeal, adding mulch to your garden will have numerous positive effects on the soil composition such as:
Slowing of the evaporation process, keeping your soil moist for longer periods of time
Regulation of the soil temperature, extending the growing season and keeping your garden green for longer
Decomposition of the mulch will increase the organic matter in your soil, attracting garden friendly organisms as well as improving the moisture and nutrient holding capacity of your soil
Suppression of weeds and unwanted growths will make maintaining your plant arrangement that much easier