Sawdust can be used as fertilizer in your garden. It improves the structure of the soil. But be careful, because the micro-organisms that convert the sawdust need extra nitrogen during a few months. Sawdust is low in nitrogen, herefore it is advised to add a nitrogen fertilizer with the gift of sawdust if your plants need nitrogen during this period.
- Sawdust - "Sawdust is a by-product of cutting lumber with a saw, composed of fine particles of wood. It can present a hazard in manufacturing industries, especially in terms of its flammability." - Wikipedia
- How to Garden With Sawdust in the Soil - "If you have heavy clay or sandy soil in the garden, it is a common practice to incorporate organic matter into it to improve moisture retention and to loosen up the texture. If organic matter is not incorporated, your plants will not thrive there; they may even die in heavy clay. One type of organic matter that can be mixed into the soil is sawdust. Nitrogen loss can occur, however, so additional fertilization may be required." - eHow.com
- Making Use of Sawdust - "Consider using sawdust when it is easily and cheaply obtainable. Prepared properly and sawdust is a great organic waste for the garden. Sawdust is low in nutrients such as nitrogen when compared against products like straw or lucerne. This factor detracts many gardeners from using sawdust. In their raw state, hardwood and softwood contain poisonous substances, which may be harmful to your plants, but they can be easily leached." - Suite101.com