Build a Permanent Raised Bed with Cinder Blocks

There comes a time in life when the thought process shifts to how can I build, repair, or purchase something that will last for the rest of my life. In my experience, wood for raised beds only lasts about 10 years or less and then the bed will need to be rebuilt. I may not be able to rebuild my raised beds 10 years from now. Unfortunately, we cannot stop the aging process and with aging, comes less physical activity. It’s just a fact of life that we all have to plan for.

Prepare the Site and Lay the Anchor Block

The site for the bed should be somewhat level, but it doesn’t have to be. In my case this already was a raised bed with landscaping timbers that rotted away and the bed became a rubbish pile for this growing season. So with all that cleared away, I’m ready to set the anchor block.

Building a raised bed to last will require some hard labor but after it’s done the bed will last for years to come. It will take 32 concrete blocks and 16 caps to build this raised bed. The first anchor block will take the longest to set in place.

The right height of the bed is determined by the depth of the anchor block in the ground. Mine will be about 4 inches below the ground level but because there is a slope, the other side of the bed will be ground level for the first layer of blocks. This anchor block must be perfectly level both ways to end up with a level bed. It’s the most important block of the entire project. Once I get the block set, packing the block holes with dirt and around the side will keep the block firmly in place.

Lay the Blocks

Then the process begins as each block is set in place in relation to the last block. 

Most blocks are accurately square and consist in dimensions. If the blocks are set with perfect fit on the top and no cracks between the top or the bottom of the blocks, the side should remain level. In my case, even with that the bed came together with a slightly different height of a 1/4 inch. I planned for that and the bed came together in a back corner. That’s OK after the block caps go on and even less when the brick facing is glued on. It’s really not too noticeable.

This bed is 4 feet wide with 32 inches of growing width and 8 feet long with 9.33 feet of growing length. This would be just fine for a raised bed like this but I decided to spruce it up a bit. If leaching of concrete chemicals into the soil is an issue for you line the side walls with a non degradable liner to keep the soil pure. Personally, I don’t think it’s an issue and didn’t do that.


Building Paths

The photo above shows one path completed. I built a weed barrier using wood chips on top to about 4 to 6 inches in depth.

The brick face is just colored and brick stamped-concrete patio blocks that are somewhat buried in the soil about 4 inches with construction glue to adhere the block to the cinder blocks. All the cinder blocks were a gift from a friend that needed to get rid of them.

I would estimate that it took about 10 to 15 hours of hard labor to build the bed and a bit more for the path. I widened the path between the bed from 24 to 32 inches to give this old body a bit more room to roam between the beds.

I have two more beds to rebuild and hope to get them done next year.

Nebraska Daveis a Nebraskan-Iowan dirt farmer-turned-urban dweller who lives to improve life with backyard compost, raised beds, vertical growing, automatic watering, and other undercover techniques. Connect with Nebraska Dave at Old Dave’s Garden blog and read all of his GRIT posts here.