Sawdust - A 2-inch layer of sawdust provides good
weed control. If applied around growing plants,
add 1/2 pound of actual nitrogen per 10 cubic
feet of sawdust to prevent nutrient deficiencies.
Fresh sawdust contains a great deal of carbon and
very little nitrogen, and its breakdown requires
that microorganisms take nitrogen from the soil.
A very thin layer of sawdust (1/4 inch) is useful
in starting seeds because it helps keep moisture
in; again, be sure nutrients are adequate. There is
often a problem with crusting of fresh sawdust,