Building Raised Beds on Any Budget

Concrete blocks: A great choice for a raised bed

🔨 How‑To Garden Guide | by Guy Saldiveri | Updated July 06, 2026

I've tried various setups for my gardens: in-ground, wooden boxes, and various raised-bed configurations. 

Most have performed admirably, but when it comes to ease of setup, overall cost, and functional longevity, only one material really shines—concrete blocks!

A quick side note: Most people use the terms cinder and concrete interchangeably. While the older blocks were called "cinder blocks" and were made with coal ash; modern-day blocks are made with cement, are heavier, more durable, and not prone to leaching dangerous chemicals.

Whichever name you wish to call them, these blocks are versatile, cheap, uniform in size and shape, and can be configured in an infinite number of ways.

The first thing to do, of course, is pull out your garden plan. You've got one of those, right? I know you do [smile]. You should have everything laid out: what's going where, how much of this, how many of that. You also should have determined the size and shape of the bed.

This is crucial. Concrete blocks are easy to work with, but once set—even in regular soil—they set up like they're in cement. Rearranging the foundation layer later can be a real backbreaker.

Concrete blocks come in a uniform size. Standard concrete blocks have a nominal size of 8" x 8" x 16". To allow for mortar joints (after all, they’re designed for construction), the actual dimensions are slightly smaller: 7-5/8" x 7-5/8" x 15-5/8". 

This little difference matters when you’re building a house, but for a raised bed, the nominal size is all you need to go by. You can also get half-blocks, and I always recommend adding a few at checkout as a just-in-case.

So now you have your dimensions, you have all the blocks you need, and you are ready to start. What now? Well, what I do is get my bed area ready. I start by clearing off any debris, then I throw down some filler like sand or cheap topsoil—something that helps stabilize the area and makes it easier to seat the blocks into the ground. Once I have that laid out, I'll go ahead and stake out the bed. 

You can refer to this diagram for stake positions and running a stringline.

Once the area is clean, smooth, leveled, and staked, you can just start dropping the blocks in place. I like to try and get my stringlines level when I run them. This makes it easy and more accurate to eyeball the blocks when dropping them in. I still like to use my 3-ft level as I go, though, just to make sure.

Quick tip from experience here: When dropping blocks, I find it easier to allow a block to scrape down the side of the last block installed—refer to diagram.

The reason I do this is so the bottom of the new block will sit flush with the bottom of the previous block. It might give you a slight gap at the top, but you can easily level it off by picking up the far end of the block and holding it up while pushing some fill in underneath it. This makes it easy and quick to level off the blocks as you go.

Using this method, plus the stringline, and a long level, you should have your foundation set in no time at all. 

Here's one of my concrete block raised bed gardens in use. Like I said earlier, they are versatile, easy to use and provide a solid and long-lasting structure that can be configured in any way you can imagine.

Okay, so now you have the foundation set up and ready for use. At this point, you can drop a second or even a third layer down if you prefer.

Note: If you are planning on multiple layers, I’d recommend laying them down in a staggered formation. Don’t stack each block directly on top of the one beneath it. Straddling two blocks is much more stable and will prevent toppling over.

I actually prefer a single layer myself. I find the blocks are tall enough to provide more than enough depth for the roots, and I always dig down into the ground partway regardless. This allows me to utilize my beds as a hybrid above‑ and below‑ground bed at the same time. It helps with water retention and nutrient availability. Plus, it gives the worms unhindered access to my soil so they can work their magic as well.

The bed is set—it's time to fill it! This is where you have some real options. The amount of soil needed to fill this area will depend on the overall size and height of the bed. The standard formula for cubic feet is length × width × height. So if your bed is 10 feet long × 6 feet wide and 1 block high, you will have 10 × 6 × 0.67, or just about 40 cubic feet. Divide that by 27 if you need to work in cubic yards—which will yield ~1.5 cu. yds. Most of the time, cubic feet is the one to use, and it makes things easy because most bags of soil are sold in cu. ft.

Here's a real-world example of one of my bed layouts with the costs (at the current time of course):

So for less than $120, you can create a bed that will look great, last for years, and provide you with enough space to grow enough veggies to keep you very happy.

Here's a link to my Soil Information page. It will provide you with a lot of information on soil and show you how I create my own mix—on the cheap!

Earlier I mentioned digging partway down into the ground. This extra step breaks up any hard pack you have, making it much easier for plant roots to strike down deep and get established. All it takes is one shovel-length into the ground and turning it over. Once you have the bed turned, you can start adding in your new soil—mixing as you go.

That’s it! You now have a fully functional and very solid raised bed that will last you for many years. The only maintenance you really need to worry about is amending your soil each year and keeping that viable. You can find more on that over at my “Soil Information” page as well.

Another word from experience here: If you decide to fill and use the holes in the blocks, beware of one thing. Shallow‑rooted plants work very well in the holes—especially things like garlic, onions, and herbs. Other plants, like peppers and tomatoes, will not. I’ve found that the roots girdle inside the block and never leave the underside to get into the ground. This makes it equivalent to trying to grow a full- sized plant in an 8" nursery pot—and that just won’t cut the mustard. Just something to think about…

Let me know how it all works out for you—I'd love to hear how you set up your bed.

Happy Gardening 🌱