How to Make a Concrete Flower Bed

Draw the outline of the concrete bed on the ground with a can of spray chalk. Dig out a 6-inch deep trench along the entire line that is at least 8 inches wide.

Fill a wheelbarrow with one bag of powdered concrete mix and add the amount of water noted on the package. Mix the material up with the shovel then pour it into the bottom of the trench. Spread the concrete out evenly with the shovel. Repeat the process to mix additional concrete until the trench has a 3-inch layer of concrete across the entire bottom.

Lay sections of 1/2-inch rebar in the center of the trench all the way around the perimeter then mix and pour more concrete to cover them. This creates a stable base for the bed. Allow the concrete to fully cure before continuing.

Mix up a bag of mortar with water as instructed on the packaging. Spread a 1/2-inch layer of mortar over the entire top surface of the concrete with a trowel.

Pick up an L-shaped concrete block and position it at the corner of the bed if it has any 90-degree turns. Install additional L-shaped blocks at any remaining turns.

Insert additional straight concrete blocks in between the corner blocks and spaced 1/2-inch apart. As you place the blocks, set a level on top of them and tap them with a mallet to ensure the entire row is level.

Spread another 1/2-inch layer of mortar on top of the blocks and install an additional row in the same manner. Position the blocks so that they do not align with the ones underneath them, thus staggering the seams and joists.

Finish the bed by installing a flat capstone on top and securing it to the topmost block row with another 1/2-inch of mortar. When positioning the capstones, you can either center them or push them toward the outside of the bed to create a 2-inch overhang.

Fill the interior of the concrete bed with top soil until it reaches 3 to 4 inches to the top.