How to Build a Raised Garden Bed With Concrete Blocks

How to Build a Raised Garden Bed With Concrete Blocks

A raised garden bed can be an impressive feature in any garden or public space. It can be achieved with a few materials, with concrete blocks being one of them. So what is the best way to make a raised garden bed with concrete blocks? Is it the best and easiest method? We will address all this and more.

In this blog, we will provide guidance on how to build a raised garden bed with concrete blocks.

At PPC Concrete Products, we are here to provide solutions for your construction needs,

from the person working their own part-time project, to commercial clients, and everyone in-between.

Monthly construction output had risen an estimated 1.6% value in June 2023, and we would like to think our accessible concrete products had a small part to play by giving our clients easy access to reliable and easy-to-use construction solutions.

Is a raised garden bed the same as a retaining wall?

Is a raised garden bed the same as a retaining wall?

Although both options appear to look very similar, they are actually not the same at all. Both options have different goals that they are made to address. Let us explain.

The purpose of both structures:

  • A raised garden bed is made specifically for planting, it elevates the soil which allows for better drainage, easier maintenance and improved access.
  • A retaining wall is built to hold back soil on a slope, or to create different levels in a landscaping project. Retaining walls are made for structural needs, and are not intended for planting on.

The difference doesn’t stop there, when it comes to height, a raised garden bed is usually shorter, and can be up to 3 feet (0.91 m) high. Whereas a retaining wall can vary in height depending on the slope it is being made to hold back.

Furthermore, the structure of both has differences within them too. A raised garden bed is a simpler structure and does not require heavy-duty reinforcement. On the other hand, a retaining wall has to be made so it can withstand the pressure of the soil it is holding against. Therefore, heavier materials such as concrete blocks must be used.

How do I know if I need a retaining wall or a raised garden bed?

Simply put, a raised garden bed is like an elevated plantar box which can allow for better gardening, whilst a retaining wall is used to help manage the slopes and elevation of your garden. Knowing which of these fits with your needs for your garden will allow you to know which option you should be considering.

How to build a raised garden bed with concrete blocks

How to build a raised garden bed with concrete blocks

A raised garden bed can be made with concrete blocks, and is easy enough to do on your own, as long as you have the time, equipment, and ability to do so. If your health is compromised, or you know you don’t have the strength or time to do so, we strongly recommend using the services of a professional.

Below is a basic outline on how to build a raised garden bed with concrete blocks:


  1. Plan your bed: Decide on the size and height of your raised bed. Remember, working height is important, so don’t make it too tall unless you plan to sit while gardening.
  2. Prepare the ground: Clear the chosen area of any weeds, grass, or debris. You can level the ground slightly for a more stable base, but it’s not essential.
  3. Lay the first course: Line up the concrete blocks in your desired rectangle shape. To ensure everything is even, you can gently tap the blocks with a rubber mallet to adjust them.
  4. Stagger the second course (optional): For additional stability, especially in taller beds, stagger the second layer of blocks. This means placing each block so it sits on two blocks from the previous layer, breaking up the vertical joints.
  5. Add weed barrier: Cut landscape fabric or cardboard to size and lay it inside the perimeter of the block walls. This will help suppress weeds from growing up through the gaps in the blocks and into your garden.
  6. Reinforcement (optional): If your bed is taller than two courses, and you want extra reinforcement, you can insert rebar vertically at the corners and potentially at even intervals along the walls. Simply hammer the rebar down into the ground until secure.
  7. Fill with soil: Fill the raised bed with high-quality potting mix or garden soil specifically formulated for raised beds. Don’t use regular soil from your garden, as it may not be suitable for planting.

What is the best concrete block to use for a raised garden bed?

Interlocking Concrete Blocks are a strong contender for being the best concrete block to use on a raised garden bed. This is because they are available in a variety of sizes to suit your needs, whilst being heavy and durable enough to provide a long-lasting structure for your garden bed.

Additionally, Interlocking Concrete Blocks forgo the need for binding materials, they can be placed upon each other and locked into place with their studs and recesses, this makes them widely applicable for raised garden beds, and even retaining walls.

Interlocking Concrete Blocks explained

Interlocking Concrete Blocks are a unique style of concrete block that you can use. These special pre-cast blocks do not require mortar in order to create a long-lasting and effective connection, and are available in multiple sizes.

Interlocking Concrete Blocks connect to each other via studs and recesses at the top and bottom of the blocks, respectively. Individually, concrete blocks are heavy, but once they are joined, they provide an excellent counterweight against exceedingly heavy applications like a retaining wall.

Available in a large variety of sizes allows these blocks to be applicable for a variety of applications, from structures that are less than a foot high, to structures that can be up to 9-feet high!

Considering the fact they do not require mortar to connect, it is safe to say you will be saving money that would otherwise be spent on binding materials, and even some labour costs. But what actually makes Interlocking Concrete Blocks special?  Well, a lot of things, specifically their range of applications.

Here is a list of some of the uses that Interlocking Concrete Blocks can facilitate.

  • Material Storage bays
  • Blast walls
  • Salt stores
  • Crash protection
  • Push walls
  • Security barriers
  • Raised garden beds
  • Segregation bays, i.e. recycling centres
  • Retaining walls
  • Industrial buildings
  • Fire breaks
  • Counterweights
  • Roadblocks

What are the advantages of interlocking concrete blocks?

  • Longer lasting and more durable than a Gabion basket
  • Quicker and less hassle to install
  • No need for mortar, saving you money and time
  • No need for steel reinforcement or shuttering
  • Resistant to extreme weather conditions
  • Fire-resistant properties, mitigating the spread of fire depending on the structure
  • Little maintenance required
  • Often, no foundation is needed before installing

The best concrete blocks for a raised garden bed

The best concrete blocks for a raised garden bed

As an established supplier all over the UK, PPC Concrete Products is always happy to help, which is why we encourage you to get in touch with any questions you may have or have a look at our FAQ.

In this blog, we hope to have provided guidance on how to build a raised garden bed with concrete blocks.’ Whilst also providing additional information including construction solutions that we offer.

Take a read of our case studies to truly understand how we have provided solutions for business in the past with the use of our interlocking concrete blocks, and ultimately, how we can help you today.

Read our blog page for more insights into our passion, construction.


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Tel: 01706 655245


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