A DIY Segmental Retaining Wall

Mark the area for the wall with a can of white spray paint. Remove the debris and plants from the area. Cut the hillside away with a shovel up to a foot behind the wall.

Dig a trench half a block deep and a couple of inches wider than the block. Tamp the bottom of the trench down with the end of a wooden board. Add a couple of inches of gravel in the bottom of the trench and tamp it down.

Check the evenness of the bottom of the trench with a carpenter’s level. Remove or add gravel to level the bottom of the trench. Place the first layer of blocks in the trench and tap them down with a rubber mallet. Fit them tightly next to each other.

Drill 1/4-inch holes 2 inches apart along the length of a 2-inch diameter PVC pipe that is the same length as the wall. Place the holes all around the pipe to improve the drainage from the hillside. Spread a couple of inches of gravel behind the first row of blocks. Lay the pipe on the gravel so the ends match the ends of the wall and cover it with gravel.

Place the next row of blocks on top of the first row, interlocking the blocks. This will create an offset seam, which makes a sturdier wall. Fill the area behind the row with enough soil to nearly reach the top of the blocks. Tamp the soil down to compact it. Continue to build the wall until it is the desired height.

Add wider capstones to the top of the wall for a finished look. This gives visitors to your garden a place to sit or an area to display decorative planters. Fill the dirt behind the capstone to just below the top of the stone and tamp down.