Retaining Walls for Flower Beds

Call your local digger's hotline. Ask them to come to your property to mark the locations of your utility lines. Many cities provide this service for free.

Spray paint the outline of your retaining wall onto the grass. Dig a trench along the painted area with a shovel. The trench's width should measure 12 inches for a stone retaining wall or 3 feet for a wood timber retaining wall. The trench's depth should be 6 inches more than the height of the stone or timber you are using. Lay a 4-foot level in the dug-out area. If one end of the trench is higher than the other, shave off some of the dirt to even it out.

Tamp down the bottom of the trench with a hand tamper. Roll out a strip of landscape fabric over the dug out area. Overlap strips of fabric by at least 6 inches. Cut the fabric a few inches larger than the garden bed using a utility knife.

Pour 6 inches of soil along the bottom of the trench and tamp it down. Set the first layer of wood or stone into the trench. Place a level on top of the first layer to see if it is level. Adjust the soil underneath the first level if needed.

Set the second layer on top of the first. If you are using stackable stones, push the lip on the bottom of the stone tight against the face of the stone it is resting on. If you are using timbers, place the second layer 1/2-inch back from the face of the first layer. Stagger the joints in both timber and stone retaining walls.

Measure the length from the last laid stone or timber to the corner of the retaining wall. Cut a stone or wood piece to fit into this space. Use a chain saw to cut the wood timbers or a masonry saw to cut stone.

Hammer 12-inch galvanized spikes into the end of each timber to secure it in place. Once four layers have been laid, pour 6 inches of soil behind the retaining wall. Rake the soil level. For walls taller than 3 feet, place a perforated drainage pipe behind the wall. One end of the pipe should extend slightly past the retaining wall to allow for water runoff. Pour more dirt behind the wall and level it with a rake.

Continue laying levels of stone or timbers until the retaining wall has reached your desired height. Fill the top few inches behind the retaining wall with gardening soil. Add fertilizer to the soil and use a shovel to mix it in, depending on the type of flowers you will be growing.