Slope Use the appropriate mulch for the topography and environmental conditions. As an example, mulching with wood chips on a steep slope with a long slope length would not be as effective as using hydromulch or erosion control blankets. General benefits of mulching The roots for most plants are located within the top 6 inches of the soil. Mulching can reduce competition from weeds within the top 6 inch layer for water and nutrients. Mulching also protects the roots from drying and keeps the temperature around the root stable.
Permeable mulches reduce runoff and prevent soil erosion.
Mulching also prevents soil detachment and keeps the salable product clean. Organic Mulches Organic mulches are derived from living sources. Apply coarse mulches such as macadamia nut shells and husks 3 to 4 inches deep. Apply very fine mulches, such as sawdust, to a maximum depth of 1 inch. Very fine mulches applied in a thick layer will cause the fine particles to settle together and reduce infiltration of water and air.