Adding mulch is a good soil erosion technique, but even mulch on a steep slope needs some help to stay in place. Varying types of mulch perform in differing ways; using the right type for the application is the first step to success. When tackling a job such as mulching a steep slope, preparation and planning go a long way to making the job last long term.
Prepare the surface where the mulch is to be applied. A soft raked soil is best if possible. The least desirable surface is a hard packed soil.
Cut the burlap or jute and lay it on the slope. It can be unrolled in panels the width of the roll, merely cut to fit the slope length. Use landscape staples to hold in place by pushing them into the ground by hand.
Apply mulch beginning at the bottom of the slope and working upward. ECM mulch is specially cut mulch, the ECM standing for "erosion control mulch." The pieces are larger and the mulch tends to stick together and to surfaces more successfully than more finely ground mulches. The mulch should be applied at a rate of 4 to 6 inches deep across the slope, building from the bottom up.
Level the surface of the mulch and pack as much as possible to secure the mulch. Wet the mulch if desired to help it bond.
Check the mulch regularly and redistribute as needed, minding areas where erosion may be taking place.