Following the rope you placed on the ground for the shape of your garden raised beds, dig out the yard grass and sod so that the basic shape of the raised garden bed is formed. Now, using your flat spade or other shovel, flatten the ground surface nearest the edge of the sod that remains for the entire length of your plant bed. This will serve as the foundation for placing your wall blocks, which have to be level side to side and fore-aft.

Once the ground is relatively flat, spread 1-2 inches of paver base on the ground surface starting at the highest elevated point to place your first wall block. Using a  tamper, tamp the paver base level. Place your first block on top of the paver base and, using a small level, determine if the block is level side to side and fore-aft. Adjust the level of the block with a rubber mallet. The top surface of your first block should eventually just be touching the string you tied off to form the level height of your wall.

Spread some more paver base and keep going with the first row of your retaining wall blocks, making sure to keep them level individually and from one adjacent block to the next. Take note that you may have to do some extra digging to make sure adjacent blocks are level with one another. Positioning the first row of blocks to be level is the most difficult part of this project, but the appearance of the wall will benefit greatly because of your efforts.

Whew! We’re almost there, keep up the good work!

Once the first row of blocks are laid and are level, you can start on the second row. You may notice that it will take more blocks on one end of your wall to be at level height with your guide string that on the other side of the wall. This is due to the grade of your lawn. Keep adding additional blocks onto the first row, until the second row is completed. Since your first row of blocks is level, so should your second and third rows be.

Lay the rows of blocks until your final wall height is reached determined either by the relative distance from the guide string or just by your visual judgement. It is fine to add partial rows to be on the top of the wall instead of ending the wall with one contiguous row. It just depends on your personal preference and how it looks in the background of the garden raised beds.

When your wall is completed, the top of the wall will be higher than the ground where you first started. Now take some pea gravel and pour it around the base of the wall on the inside of the plant bed to promote proper drainage. Start to backfill the plant bed with the soil of your choice, possibly adding more layers of pea gravel against the wall or other edges of the bed for proper drainage.

Once you have completely filled the garden raised bed with the soil, you are done, and are now ready to add plants and flowers of your liking, maybe a few colorful accessories.

See also:

Setting Up a Square Foot Garden