How to Make a Raised Flower Bed with a Block Border

Lead Image
What You'll Need
Pencil, paper and paper
Tape measure
Garden hose
Tamp or plate compactor
Cold chisel
Baby sledge hammer
Pea gravel
Regular blocks
Special blocks
Cap blocks

Create a sturdy and natural looking raised flower bed with interlocking concrete blocks. Landscape and garden supply stores carry these blocks in a variety of shapes, sizes, surface textures and finishes. The interlocking nature of the blocks allows for simple dry stacking. Raised flower beds require less kneeling and bending than flower beds on the ground.

Step 1 - Choose Your Block

Find the dimensions of the block you choose. Make note of any special interlocking technique or device. Also make note of any specialty blocks, such as corner blocks, curvy blocks and cap blocks. Lastly, make note of any manufacturer’s installations requirements such as minimum foundation depth or maximum wall height.

Step 2 - Lay Out the Bed

Choose a level area and lay out your raised flower bed with stakes or garden hose, remember that a larger area requires more blocks. Measure the perimeter in inches and divide the perimeter by the width of the block. The quotient equals the number of blocks per course that you need. Increase or decrease the perimeter of your flower bed to a whole number of blocks. Plan a minimum of 2 base courses and a finish course. Do not exceed the manufacturer’s maximum height.

Step 3 - Create A Foundation

Cut out sod and dig a trench 6 inches deep, 16 inches wide, and level. Compact the earth and add 3 inches of compacted pea gravel.

TIP: Our expert gardening advisor, Susan Patterson suggests, "Use the sod you cut for repair or replacement in your yard."

Step 4 - Set the First Course

Choose a spot to begin and lay out the first course of block so the face of the block meets the outer edge of the trench, burying the first course of block about 3 inches. Adjust the blocks if needed to complete the circuit, then lightly pack pea gravel in between and behind the blocks.

Step 5 - Lay the Second Course

Stagger the second course over the first so the joints of the second course are in between the first course. use the interlocking mechanisms as required. Crack a block in half with a cold chisel and baby sledge hammer if necessary, to complete the circuit. Lightly pack pea gravel between and behind the blocks. Add more courses, if desired, up to the manufactures maximum height while lightly packing pea gravel in between and behind each course.

Step 6 - Lay the Finish Course

Finish the final course off with cap blocks.

Step 7 - Fill In the Bed

Use pea gravel on the bottom of the flower bed to promote drainage. Mix up some soil, plant your favorite flowers, and watch them grow.

TIP: Susan adds, "Use rich compost for your flower bed and finish with 3 inches of mulch to help with soil retention. Always choose flowers that are suited for your region. "