Raised garden beds are an attractive addition to your home's landscape. They make it easier to tend to your garden from the slightly higher position and they help prevent seeds or flowers from washing away during heavy rain. Breeze blocks make a sturdy base for a raised garden bed. If you are not too keen on the grey colour, purchase a concrete stain and paint the blocks prior to building the raised garden bed.
Mark out the bed's length and width on the ground using spray paint. Consider the width of the breeze blocks when determining your raised flower bed's final size.
Dig a trench 6 inches deep and wide enough to accommodate the breeze blocks. Use a hand tamper to tamp down the trench. Place a level in the trench and fill in any low spots, tamping them down. Work your way around the entire trench with the level until you have a sturdy base.
Fill the trench with approximately 4 inches of crushed gravel. This is especially important if you live in an area where the ground freezes. During freezing and thawing the ground heaves. The crushed gravel helps protect the breeze blocks and keeps them from being moved around too much.
Lay the breeze blocks in the trench. Push them tightly end to end. Lay a level on top of the blocks. Place dirt under any low areas. Butt the breeze blocks up at a 90-degree angle at each corner.
Place another row of breeze blocks on top of the first row for a slightly taller raised bed. Stagger the breeze blocks so that the first layer's joints touch the centre of the breeze block above. This gives the raised flower bed more stability.
Measure the height of the raised flower bed. Use a metal cutting hacksaw to cut a piece of rebar approximately 4 inches taller than the bed's height. Place a piece of rebar into every other breeze block hole. Hammer the rebar into the ground approximately 4 inches. The rebar helps support the breeze blocks. Skip this step if your flower bed is only one breeze block high.
Pour a bag of dry cement into a wheelbarrow. Add water according to the manufacturer's directions and use a shovel to stir the mixture. Pour the cement into each of the breeze block's holes. Use a trowel to smooth the cement's surface, giving the flower bed's top a finished look.
Allow the cement to harden for 48 hours. Fill the raised flower bed three-quarters of the way full with dirt. Finish filling the bed with top soil. Plant your flowers.
Instead of cement, fill the breeze blocks' holes with dirt and plant flowers along the bed's edge. Make the raised garden bed sturdier by filling the trench halfway with cement before placing the breeze blocks in it.