SAWDUSTSawdust is often used as a mulch material around herbaceous perennials and woody ornamentals.
Problems can occur as sawdust starts decomposing. Soil bacteria may tie- up or "borrow temporarily" some available nitrogen. The constant addition of sawdust may cause plants to appear stunted and yellowish.
As the sawdust finishes decomposing, nitrogen will be returned to the soil.
A handful of a complete fertilizer scattered over the sawdust should limit any temporary nitrogen depletion.