How to Add Soil to a Hill Slope

Sloped gardens are difficult and are known for losing their soil through runoff and erosion. If you want to provide more gardening space in your yard and stop losing topsoil to rain and wind, terracing your hill is likely the best bet. When you put in terraces, you build walls along the slope and then backfill them, adding more soil until the level of the ground meets the level of each wall. This provides your yard with stability and allows water to soak into the ground rather than constantly run over the top of it.

Shovel

Crushed gravel, ?-inches wide or less

Lawn stakes

String

Retaining wall blocks

Sand or gravel

Purchased topsoil

Begin at the bottom of your slope. Dig out a shallow trench in a straight line, digging down 1 inch for every 8 inches of planned retaining wall height, plus 4 to 6 inches for your base layer. Lay down 4 to 6 inches of crushed gravel (not pea gravel), ?-inches wide or less, packing it down by hand.

Stake out a line along your trench, using two lawn stakes and a string tied between them. Stack retaining wall blocks, using the string as a guide, next to one another, offsetting the second level by half a block and pushing them back an inch or two to create a gradual inward lean toward the hill.

When you have constructed your wall, backfill using a well-draining material like sand or gravel against the stones to allow water movement. Fill the rest with purchased soil, which drains well and compacts less than garden soil. Continue this process up the slope.

For a steadier base, use a level to make sure the gravel is flat before adding stones. If you want to ensure it is extremely solid, rent a plate tamper.

Always build retaining walls in toward the slope. Walls that are straight up and down or lean outward may topple.