By adding small amounts of sawdust to the soil, along with a nitrogen-releasing fertilizer, organic matter can be increased. Heavy clay soils can benefit from some sawdust because it will decompose quickly and improve the texture of the soil over time.
Sawdust fits into the brown or carbon-heavy material within a compost pile design. Brown materials should be mixed with green materials such as kitchen waste and discarded grass. By adding sawdust, homeowners also make a compost pile easier to turn over and aerate, which helps break down material more quickly. Rich compost incorporating sawdust takes about a year to finish. Finished compost can be used generously on many plants.
Since sawdust tends to decompose slowly, it serves as an effective weed killer in home landscapes. It can be added in the spaces between stone or concrete components in a garden like walkways or decorative areas to discourage weed growth. In the same way, sawdust serves as a perfect mulch, particularly for acid-loving plants. It holds down weeds around plants as well as breaks down slowly to amend the soil over time. Besides discouraging weeds, coarse sawdust can also repel slugs and other pests from damaging plants.
Sawdust has more unusual uses in a backyard landscape as well. It adds a lovely scent to the garden area, can help homeowners control erosion of their land, and absorbs leaks from gardening machinery.
Coarse sawdust from sawmills is the best type for homeowners to use in landscapes. It offers more benefits than very fine sawdust. Homeowners willing to pick up sawdust from mills can often source it at little or no expense.