- Mark out the planned location of the retaining wall around the garden with brightly colored spray paint.
- Use a shovel to dig a trench for the retaining wall. The trench should be deep enough for you to bury 1 inch of slate blocks for every 8 inches of the total height of the retaining wall.
- Apply a 4-inch layer of crushed stone and compact it with a hand tamper.
- Add 1 inch of coarse sand to the crushed stone. Compact again.
- Lay the slate blocks in place atop the coarse sand. Lay them as closely together as possible.
- Pour crushed stone over the first row. The crushed stone goes between the joints to fill them in.
- Continue adding rows of slate blocks and pouring on crushed stone. Use a level and string to ensure the rows and columns are even before adding additional rows.
Building a Slate Garden Retaining Wall
A retaining wall can be a useful addition to your home's garden. The retaining wall should at least span the entire length of one side of your garden, but it can continue and go all the way around, depending on how much of the garden you want to protect. Either way, you need to take measurements and plan carefully throughout the process. Slate is a quality material to choose for the stones that make up the retaining wall. Slate blocks are both long-lasting and attractive, and are likely to match almost any type of landscaping you may have around your home.