Mulch has been the subject of many garden articles to the point that most gardeners now use mulch as a matter of course in areas where retaining even moisture in the soil is important. In this article, I'm going to discuss the advantages and disadvantages of different types of mulch that are readily available.

Inorganic mulch, like gravel, is in fact a type of mulch suitable for xeriscaping because it drains and dries pretty quickly. When applied in sufficient quantity, for example two inches thick, it effectively suppresses weeds and makes pulling them easier. Pea gravel is a good example. Expanded shale is another. Pea gravel is heavier than expanded shale and tends to hold firm, where expanded shale tends to wash out faster on a slope. But because expanded shale is lighter and less dense, it tends to dry out faster. Another example of gravel mulch is river rock. Unfortunately, river rock mulch can be difficult to weed when weeds with deep roots sprout.