For years, I was jealous of my friends who had raised gardens in their yards. The lush produce seemed to defy the laws of nature. The only thing that kept me from having one was the thought of building my own raised garden. I didn’t think it would be too difficult, but I wasn’t sure how to go about starting it. Then I learned how easy it is to make a raised garden using retaining wall blocks! This article will show you a step-by-step guide on how to build your own raised garden using retaining wall blocks and ensure your project succeeds.
Start with a slope.
The first step in building a raised garden bed is creating the slope. You want to slope the soil away from your house, driveway, street and sidewalk. This will allow water to run off the surface of your garden and not pool up on top of it. If you have trees around your home, make sure that you consider them as well when deciding where to place your beds so that they don’t block any sun or drainage from reaching them.
Pick up materials.
- Pick up materials
You’ll need the following items:
- Retaining wall blocks (or bricks)
- Soil (preferably loamy, slightly sandy soil)
- Mulch (at least 2 inches thick) or bark chips to retain moisture in your soil. You can also use aged manure if you don’t want to spend money on mulch or bark chips. This will help keep weeds at bay and add nutrients to your garden bed.
Plan your design.
- Plan your design.
Before you get started building, you’ll want to plan exactly what you’re building and how it will look. It’s helpful to have some sort of drawing that shows the dimensions of your garden, as well as its overall layout. You should also consider things like access points and maintenance areas while planning out your design.
Begin installation in the back of your garden.
Start in the back of your garden. This will give you ample time to access the blocks and make sure they are level before adding more courses of blocks.
You can begin with a level base, or build up to a level base using retaining wall blocks. If you choose to start with one block and work up, make sure that it is set perfectly straight and square before adding another block on top of it. Otherwise, your wall will not be straight or sturdy.
Create a level base for your first course of blocks.
The first step in building your garden bed is to create a level base for the first course of blocks. You can use any number of tools, but these are some options to consider:
- A level
- A spirit level
- A laser level (you may want to rent this from a tool rental company)
If you don’t have access to any of these tools, you can always just eyeball it and make sure that the ground looks flat and even on both sides of your wall before laying down any concrete blocks.
Fill the spaces between the blocks with soil backfill.
Fill the spaces between the blocks with soil backfill. Use a shovel or trowel to fill the space between your retaining wall blocks until they’re filled to at least half their height. Compact this material by hand, then use a level to make sure that each block is level with its neighbors and that your bed is level overall. Fill in any gaps at this point; if some areas are deeper than others, use additional blocks or crushed stone (also known as gravel) as needed to create an even surface for planting.
Compact the layers as you build up to prevent shifting.
Once you’ve laid the blocks, it’s time to compact the soil. You can use a tamper to do this, but it’ll take more time than you have. A plate compactor is also effective, but it’s not as fast as using a hand tamper or vibrating plate compactor.
You can purchase a manual plate compactor and use that on your raised bed walls if you want to get things done quickly and efficiently, but they’re quite expensive when compared with other options. If you’re building many raised beds at once or don’t want to spend money on an expensive tool, stick with using a hand tamper instead of anything else.
Add more retaining wall blocks to build up your garden wall.
Now that your wall is starting to take shape, it’s time to add more retaining wall blocks and continue building your garden.
- Add one additional block per foot of height (1/2 inch) that you want the final wall to be. For example, if you have a raised bed with an 8-inch depth and want it to be 15 inches high, place 12 blocks across the top of your base so that when viewed from above the top edge of each block lines up with its neighbor’s bottom edge.
- In this step, we’ll start by placing two retaining blocks side by side at the end closest to where we just added our first block in step 2 above. This will create a backing for which we can compact our soil firmly against (this will help prevent erosion). Place one retaining block perpendicular on top of this pair—this is because we’re going to fill in around these three blocks with loose soil from below before moving on; doing so now would make compaction difficult after filling in around them later without doing any work beforehand.
Line a trench around the outer edge of your raised garden bed with retaining wall blocks.
- Line a trench around the outer edge of your raised garden bed with retaining wall blocks. The trench should be at least a foot deep and wide, depending on how many blocks you’re going to use.
- Line the trench with blocks up to the top of the raised bed, leaving an inch or two gap between each block for drainage.
Fill the trench with soil backfill and compact it well before adding mulch or bark chips.
Fill the trench with soil backfill and compact it well before adding mulch or bark chips. Compact the soil again after you add each layer of mulch, which will help prevent water from settling on top of the retaining wall blocks and rotting them prematurely. Repeat this process until the trench is filled to your desired height.
A raised garden bed can be built in an afternoon using retaining wall blocks as a frame, plus soil and mulch to fill it in.
Building a raised garden bed is an easy DIY project that can be completed in an afternoon. The biggest challenge with building a raised garden is finding the right materials to use. Most people don’t have any experience with building retaining walls, and they may not even know where to begin searching for them! Fortunately, there are plenty of resources available online that will guide you through the process step by step.
Retaining wall blocks are made out of concrete, which means they’re tough enough to withstand years of heavy use without breaking down or splintering apart like wood would over time. They’re also much easier than other materials such as bricks because they come flat instead of needing mortar between layers (which makes them lighter weight).
Once you’ve laid out your retaining wall and built it up, the best way to finish is by backfilling with soil or mulch. This will help keep the structure sturdy and protect it from erosion or movement. You can also use polymeric sand in between your blocks, which will prevent weeds and insects from getting into your garden. The last step is to plant whatever you want inside of your raised bed—from flowers and vegetables to herbs or grass—and start enjoying it! We hope this guide has helped you learn how easy it is to build your own raised garden with retaining wall blocks and turn any outdoor space into an oasis.