A Complete Guide to Making A Cinder Block Raised Garden Bed

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Growing your own plants, fruits and vegetables can feel very rewarding. But, if you are thinking of adding a little extra style to your backyard garden, you could go for cinder block raised garden beds! They look very impressive and add a professional touch. But how do you make a cinder block raised garden bed?

Making your own raised garden bed might seem daunting at first, but it’s a simple process. Once you have bought the necessary products, you can start building them yourself. It’s as easy as laying a bunch of cinder blocks side by side in any shape you like and filling the insides with soil.

Before you go all out, let’s take a look at some factors you should consider before building your garden bed with cinder blocks. I’ve discussed everything from the procedure to safety concerns when it comes to building a cinder block raised garden bed.

Making A Cinder Block Raised Garden Bed

Even before you start buying things, you need to plan out where and how you will place your garden bed. Get an approximate measurement of the overall area you wish to cover and calculate how many cinder blocks you will need. Your cinder blocks will usually have a length of 16 inches, so keep that in mind. If you have some lying around, then make use of those ones first.

Otherwise, you can buy them at any home improvement store. Once you know how many you’re going to need, you’re ready to start buying/getting the rest of the tools. Here’s a list of everything you will need before you start your project:

  • 8” x 8” x 16 “cinder blocks (as many as you need)
  • Protective gear like gloves and closed-toe shoes
  • Cardboard or painter’s paper
  • Enough compost/topsoil mix to fill your garden bed
  • Rake
  • Seeds for plantation

Once you have all of these ready, you can start on your project. Wear your gloves and even a hat if it’s too sunny and get working. Follow this step-by-step guide to help you.

Step 1

First, you need to level the area you want your garden bed on. It doesn’t have to be too precise, as long as the cinder blocks can sit properly, you’re good.

If moss or other weeds are growing on your chosen patch of land, you can clean those with your hands. Remember to wear gloves, though. You don’t have to clean too deep because you will be covering it with cardboard, anyway.

Step 2

Once your surface is ready, take your cinder blocks one by one and place them one by one in a rectangular shape, or any shape you want. Be sure to leave sufficient space in the middle for your plants. You can go as big or as small as you want with this. You can also layer cinder blocks to increase the height.

Place your cinder blocks horizontally, leaving the hollow spaces facing upwards. Remember to wear protective footwear to protect your feet and toes and be careful not to drop any cinder blocks on your foot. They are very heavy and can break your toes.

Step 3

After you are satisfied with the shape of your garden bed, you can go ahead and line the empty area in the middle of the boundary with some cardboard. If you don’t have cardboard lying around, you can easily buy painter’s paper from the paint section at any home improvement store. If you can’t find either, simply place down newspaper sheets to cover the opening.

This helps to smother the underlying surface vegetation and it is much easier than digging them out from the ground. Digging it up also will cause more trauma to the soil. The cardboard or newspaper, whatever you end up using will eventually decompose and mix with the soil.

Step 4

Now just place some compost or topsoil mix into the opening, making sure to cover the whole patch. Try to even out the layer and the height of the soil should reach almost the same height as the cinder blocks.

Now your garden bed is ready for planting. Get your favorite seeds and plant them right away. You can even put in soil in the cinder blocks hollow space and grow plants in there to add an interesting look to your garden.

See, it was that easy! With just 4 simple steps you can enhance your garden with a raised garden bed which is not only amazing but is also functional. It looks much more impressive and it will protect your garden from pests and weeds.

If you start seeing drainage problems in your cinder block raised beds, I have a whole other article on this site talking about the best ways to improve drainage in raised beds!

How Much Does It Cost to Build a Garden Bed?

Making garden beds can cost you anywhere from about $20-$30 with some being much more expensive depending on how you build and what materials you use. But with cinder blocks, the process is very cheap. Each cinder block usually costs about $1, so depending on how many you use you can calculate your estimated cost. 

If you have cinder blocks lying around from a past project, then the process becomes even cheaper. Your main expenses will come from the soil. Good quality soil can be expensive. Try to buy compost and mix your soil to save yourself some money.

Soil prices can vary according to how much you buy and where you buy it from. So you can get a quote from your local hardware store or the plant section at any home improvement shop. You can also order it online and it will reach your doorstep in a matter of days.

Even if it’s expensive, try to get the best soil because this is what determines your garden’s health. Now, having some lying around does cross out that expense. It becomes cheaper than $30 to build your raised garden bed.

Apart from the seeds, you will probably have gloves and cardboard lying around the house. Seeds themselves aren’t usually that expensive. If you have gardening experience, the expenses are pretty much the same as you would expect when taking care of other plants. Prices can vary according to which kinds of plants you are growing.

So, the overall expenditure will vary depending on what you do and don’t have lying around already, but it is usually very cheap to build a cinder block raised bed. Expenses can creep up depending on how you choose to build your raised garden bed. But if you already have been gardening for a while, chances are you might have all of the materials lying around.

Are Cinder Blocks Good for Raised Garden Beds?

Yes, Cinder Blocks are great for raised garden beds. They are cheap and durable and protect your garden from pests and unwanted growth. While there is talk about cinder blocks being toxic to your soil, there is no solid research or scientific backup to this claim. If you are worried about soil quality, you can always keep testing it.  

Cinder Block Raised garden beds make it easier for people to start a garden anywhere without having to dig through dirt and prepare the ground for planting (which can get very expensive).

Let’s check out the benefits of using cinder blocks for raised garden beds:

  • Cheap

Cinder blocks are one of the most affordable options when it comes to making raised garden beds. Their prices usually vary in size but the smaller ones will only cost you a few dollars.

Chances are the standard 8”x8”x16” sizes will work best for you. These cost only a few dollars and are perfect for medium to small sized gardens. So even if you buy a lot of them, it won’t put a hole through your wallet.

  • Availability

Cinder blocks are very easily available and you can find them almost anywhere. Check your local hardware or garden materials store and they will probably have it. If all else fails, you will find it at Home Depot or other home improvement stores.

It also does not matter which part of the world you live in. You can get them in all countries. They might even be lying around the home if you had construction work done, as they are very commonly used.

  • Customizable

You can also greatly customize your cinder blocks. Place them however you want to create different shapes and designs. You can even stack them higher and higher according to your needs for an even more elevated surface for your garden. If you have back pain for instance and can’t get down much, an elevated garden bed is easier to tend to.

These can also be changed and removed if something ever happens. You do not get this accessibility with materials like wood or metal which would be nailed into place and hard to remove.

  • Durability

The best part about cinder blocks is that they are very durable. They will last you much longer than a wooden raised garden bed. Wood decomposes and might rot after getting exposed to rain and humidity.

Come rain or storm, your cinder blocks won’t break and will protect your garden bed. They are built to last. The best quality cinder blocks are even better in durability and strength.

As you can see, not only are cinder blocks good for your garden bed and soil, they also provide several benefits. If you’re thinking of building a raised garden bed, cinder blocks are the way to go.

Is There A Difference Between Concrete Block and Cinder Block?

Yes, though cinder blocks and concrete blocks look very similar to one another, they are structurally very different. Even though their names might confuse you, cinder blocks are made with concrete and coal cinder whereas Concrete blocks are made of steel, wood, and cement.

Concrete blocks are much heavier than cinder blocks, as they usually contain stone or sand and cement. These are heavier duty and you will see them being used in buildings and pavements, etc. But for garden beds and DIY projects, cinder blocks work just fine as they are much easier to lift and work with. Concrete blocks are also more expensive.

Traditional cinder blocks are made only with cinder and contain fly ash as an aggregate. This ash can sometimes seep into the soil, but it hasn’t proven to be too harmful. So, if you want to be sure you can ask your store owner exactly what your “cinder” block is built out of.

However, having said that, we usually use these two terms interchangeably, especially when it comes to garden beds. A lot of the modern cinder blocks do not even use fly ash, and are made of concrete and hence often called concrete blocks. So, it can get pretty confusing for some.

Either way though, even if you have concrete blocks your outcome will not differ that much. They can be used in the same way as cinder blocks can, so don’t worry too much about the differences.

What Grows Well in Cinder Blocks?

Depending on the height of your raised garden bed built with cinder blocks, plants that have similar root sizes will grow best in these spaces. What I mean is, if you are only using a single layer of cinder blocks your soil does not run too deep. So, plants that have shorter or spread-out roots will grow well in cinder blocks and garden beds.

Let’s take a look at some of the options you could try with your cinder block garden:

Carrots

You can grow carrots for yourself not only on the garden bed but also inside the cinder block holes. Try out different varieties and see which one’s work best for you. You’ll be left with beautiful carrots.

Experiment with longer varieties as well, especially if your stack of cinder blocks is much higher. Or if your cardboard has decomposed, your soil can now run much deeper than the cinder height. So, you can try different varieties and see which one’s produce good results. Remember that carrots usually need two to three-gallon pots for healthy growing.

Tomatoes

Tomatoes are another great option for cinder block gardens. The determinative varieties will grow great with the support of cinder blocks. As cinder blocks can trap heat, this provides a warmer environment for these tomatoes to grow juicy and fresh.

These will usually take up about 5-gallon pots, so fill your soil accordingly. The roots will need some space to spread out properly.

However, you shouldn’t try to grow indeterminate varieties of tomatoes because they will require a much stronger support system and also regular pruning.

Onions 

You can also grow onions in your raised garden bed. While these onions have short roots, they are heavily concentrated around 8” of the plant. So space out your onions, if you do end up growing them. Otherwise, they will have to compete for nutrients and grow poorly.

You can also spray fungicides to your soil to prevent any fungus or disease from forming and ruining your crops. If you want to increase your produce you can simply make other beds and grow them side by side.

Lettuce

If you love salads, lettuce is a great vegetable to grow in your raised garden bed. You sow the seeds at least 12 to 18 inches apart and try to do it in warm weather.

Since you will be taking off the lettuce heads, you want to encourage leaf growth rather than root growth. Your roots shouldn’t go much deeper than 6 or 7 inches depending on soil height. Add in a few cherry tomatoes here and there for more ingredients to your salads.

Pre-made Plant Mix

If deciding and designing feels too complicated for you, there are plenty of plant options online that you can buy. Don’t worry as you can get plant mixes specially designed for raised garden beds.

They will even come with instructions and tell you exactly how to take care of them. Couldn’t be simpler, right? These mixes have been tested and work together really well. So as long you follow instructions properly, you’ll be growing a whole range of different plants on your garden bed. This is perfect if you are a beginner or time poor gardener 🙂

So as long you follow instructions properly, you’ll be growing a whole range of different plants in your garden beds.

As you can see, there are many different options to what you can grow in your cinder block raised garden bed. Starting from vegetables to even small fruits, you can grow them all. If you don’t want to grow food, you can also opt for flowers or leafy plants that grow well in little soil. The options are endless.

Conclusion

By now I’m sure you’ve learned how to make a cinder block raised garden bed to a good standard. As you can see, it is pretty simple. And, following my guide to the letter, you’ll be looking at your very own garden in no time. Also, picking the right plants for your garden can also make things a lot easier.

Thanks for reading and I wish you best of luck on building your cinder block raised garden. Until next time, farewell.