Function

• Cedar chips make an effective mulch for garden beds and discourage weed growth. The wood gradually breaks down, returning organic material to the soil. Landscape fabric, a synthetic product, doesn't benefit the soil organically but is an effective weed barrier. Gardeners usually cover landscape fabric with a layer of mulch.
  
  

Benefits

• Along with suppressing weeds, wood mulch and landscape fabric warm the soil, allowing for earlier blooming in spring. Both are useful in preventing soil erosion.
  
  

Geography

• Cedar chips and landscape fabric are generally not recommended for vegetable gardens and annual flower beds, where digging and tilling occur often. Once laid, landscape fabric prevents digging in the soil, and cedar chips should remain on the surface of the bed, not tilled into the soil.
  
  

Warning

• Cedar contains phytotoxins that can damage young plants. The danger is greatest with sawdust and small chips that filter down through the soil. Large cedar chips used as mulch are generally safe.