September 9, 2008
Laurie, your very best bet for free mulch is grass clippings from a yard that has not been treated with herbicides. Not only will the clippings smother the weeds, they will enrich the soil, providing nutrients for the annuals, perennials and bushes they are protecting. Check out this article on more ways to build better soil while discouraging weeds.
If you have a sawmill close to your home, you may be able to get sawdust to use as a mulch. While not as nutrient rich as grass clippings, it will smother weeds. Cotton seed hulls are another good mulch, especially if you live in cotton country. The trick is to find a local product to use as mulch so you are not ramping up your carbon footprint while depressing the weeds.
— Heidi Hunt, assistant editor Mother Earth News