Mulch

An organic soil covering such as leaves, straw or peat, placed around plants to maintain soil temperature and prevent the evaporation of moisture, the freezing of roots, and the growth of weeds.

Mulch improves soil fertility and structure, reduces pest and disease damage, prevents erosion and can even improve the flavor of crops. Some use it for decorative purposes as well (uniform look to landscape). There are many types of materials that make good mulch. Any kind of coarse well-decomposed organic matter (compost) will work: leaf mold, grass clippings, aged sawdust, pine straw, ground bark and aged stable bedding (straw). Shredded leaves, (even when fresh), make good mulch.