Mulching a steep slope is an effective way to landscape an area that can be dangerous to mow. Mulching also prevents soil erosion and adds depth and interest to an uninteresting and unused area of your yard. If you ever want to plant the slope, the mulch will help prepare the soil.
Lay burlap cloth or wet newspaper over the slope. Burlap and wet newspaper will grab onto the surface well and, if your slope is covered with grass, this will help smother it.
Purchase enough mulch to cover your slope at least 4 inches deep. Shredded hardwood mulch will work best since it will grab onto the burlap and newspaper and stay in place on the slope, according to Pennsylvania certified horticulturist George Weigel.
Spread the mulch evenly over the slope. Pack it gently with the back of a shovel.
Build a 4- to 8-inch tall retaining wall out of fence posts, large boards or landscape bricks if you are concerned that the mulch will wash away. Otherwise, you can simply rake any mulch that gets washed to the bottom back onto the slope.