SHTF blog – Modern Survival

How to Build a Concrete Block Raised Bed Garden

Do you have lousy soil but want to start a garden? Got cinder blocks? Build a concrete block raised bed garden!

The advantages to raised bed gardening are many:

  • They’re easier to weed (less bending over).
  • There’s no tilling required (less compaction from stepping on the soil).
  • They’re easier to work (again, less bending over).
  • You can build your own soil.
  • The soil warms earlier in the spring.

The disadvantages to raised bed gardens, particularly concrete block raised bed gardens, are that they require extra labor and cost to construct. They also tend to require more watering. People build their raised bed gardens in a variety of ways. If money is no object, you can use red cedar or stone. Some use pressure treated lumber while others refuse on toxicity grounds. It’s largely a personal choice. The lowest-cost option to build raised beds is actually free, you just pile the dirt into mounds. I prefer concrete blocks!

Why concrete block raised bed gardening?

  • Concrete blocks are easy to salvage from random places: vacant lots, behind barns, and wherever else.
  • They provide a nice, wide platform that you can sit on to plant, weed and water.
  • No drilling or screwing required, just drop into place.
  • Easily adaptable to form hoop houses, screen plants, etc.
  • I think they look kinda cool.

I began construction of the first bed in the late summer so it’d be ready for spring planting. That also gave weeds a chance to grow, which I then killed, reducing the next year’s total weed count.

This is how it looked at the first phase:

concrete block raised bed

What may not be apparent in the photo is that I actually dug out dirt for the first row of concrete blocks so they’d sit below ground. I thought this would help stabilize the bed a bit from frost. The bed is loose fit (no mortar), and I didn’t want to find the bed heaved all over the place with the spring thaw. I’m not sure if it was necessary or not, but the bed still had nice, level lines after winter. You could save some work (and materials) if you made the bed one row shorter.

In the background of the above picture you’ll see four piles of dirt. The one on the far left is aged horse manure. In the center at the far back is screened loam. The smaller, darker pile to the right of that is homemade compost. And the pile in at the right, with the shovel sticking out of it, is the crap, clay-like soil I dug out of the ground.

I mixed the aged horse manure, screened loam, and compost together in the wheelbarrow (1/3 of each). Check the action:

dirt.JPG
Note that it appears two blocks high here (one row buried).

You can see I had to fence the raised bed because of the deer. You can also see that I capped the walls with additional flat blocks. I already had some on hand and it gave a nice, finished look that doubled as convenient seating for weeding.

Optional Construction Ideas

  • Concrete blocks may wick some of your water. You can line the inside walls with plastic sheeting if you want to prevent this; and in retrospect, I should have done this. The plastic can be tucked under the upper flat to hold it in place. Cut the plastic off at the base of the walls before back-filling the bed with soil. Never run plastic under the bottom of the bed. You need the drainage.
  • For super duper stability, you can drive rebar inside the block holes and back fill it with gravel. That was my original intent, but then the “overkill” voice was ringing in my head. I didn’t deem it necessary. Besides, if blocks do move, they’re easily re-aligned. Because the soil doesn’t compact, it’s simple to shovel dirt away from the wall and re-set any blocks. The soil stays nice ‘n fluffy.

Here are additional pictures:

side-view.JPG

Raised Beds are Ideal for Square Foot Gardening

Pictured here is some eggplant, peppers, and broccoli. Already harvested from the raised bed was radishes, carrots, two types of lettuce, and spinach.

raised-bed.JPG

I coupled the raised bed with the square foot gardening technique. If you’re new to gardening, it’s a great way to get a grip on planting and spacing. It’s a technique that’s similar to the long-used French intensive gardening approach. From Wiki:

French intensive gardening, also known as biodynamic, raised bed, wide bed, or French market gardening, is a method of gardening in which plants are grown within a smaller space and with higher yields than other traditional gardening methods. The main principles for success are often listed as soil improvement, raised beds, close spacing, companion planting, succession planting and crop rotation. Originating in France, the practice is popular among urban gardeners and small for profit farming operations.

If you’re new to gardening, and in particular, square foot gardening, you’ll want a copy of Mel Bartholomew’s best-selling book All New Square Foot Gardening.

Building a Plastic Tunnel Cold Frame

You can extend your growing season on the early and the late end by building a plastic tunnel over your bed to protect your plants from colder temps. While I didn’t do it over my concrete block raised bed, it is easily accomplished. You can essentially build this setup right on top of it.

cold frame raised bed

Instead of screwing the flexible Pex tubing into boards, you can insert that tubing directly into the holes of the cinder blocks (without the flat concrete cap stones on top, of course). Run some rigid PVC tubing (available at your local home improvement store) lengthwise across the flexible tubing just like in the picture. Cinch the PVC to the Pex tubing with zip ties. Run vinyl gauge fence over the frame (just like in the picture) and cinch it with the same zip ties. You can buy the garden fencing here or at your local garden store.

Then cover it all with plastic, something like DeWitt Supreme Plant Frost Protection Blanket. When the cold period has passed, keep your frame in place and then use insect netting over the frame to protect the plants from destructive bugs.

Related Raised Bed Garden Supplies

roll of twine
A roll of twine is great for square foot gardening.

Inside the bed in the picture above you’ll see strips of scrap lumber I zipped off to measure square foot grids. What also works to mark your measurements is a simple roll of inexpensive, biodegradable twine. Using a concrete block bed like the one in this post, you can hold the lengths of twine in place by simply inserting the ends under the flat blocks capping the walls.

canning guide

Then, when you’ve inevitably produced way more vegetables than you can eat in a season (a common beginner’s mistake), you should buy a copy of the USDA’s Complete Guide to Home Canning. It’s the go-to source on canning, and it’s inexpensive. You can get a pressure/canner cooker to accompany canning supplies and Mason jars that run from the high-end All American 930 to the more reasonably-priced Presto 8-Quart cooker.

What’s your experience with raised beds and square foot gardening? Help others learn by adding to the comments below. Garden on!

Save

Get New Posts by Email

Subscribe to our mailing list and all of our prepping content delivered to your email inbox.

Thank you for subscribing.

Something went wrong.

127 thoughts on “How to Build a Concrete Block Raised Bed Garden

  1. Yours are much neater than ours. LOL! We also planted in the blocks. Our soil mix was 1 part compost, 1 part sand, 1 part peat moss.

    I grew more out of the 2 concrete block beds than I have in my 40X80 ft. regular dirt gardens. You can also plant much closer in the concrete beds, and they warm up faster in the spring. Have fun!

    Just found your site today. Have enjoyed reading your posts.

    Steph

  2. Love your info on raised bed gardens. I am in the process of collecting my cinder blocks so I can start one. I moved into town and really miss my garden. Thanks for the tips. Rowena

  3. Thanks for taking the time to explain and demonstrate this gardening idea. It answered some questions for me without the cost and time of my own experimentation.

  4. Kevin, no known contaminants in the concrete. I talked with staff at MOFGA (www.mofga.org) before constructing, because I had similar questions.

    If it’s on top of concrete, though – how are you going to resolve the drainage issue?

    1. If you cut a hole in the bottom layer of blocks, you can insert a pvc pipe with a twist on/off into this hole.. Lay the pipe flush with the ground and use the on/off to control the water flow.

  5. We are considering gardening on top of some concrete in our neighborhood. Are there any issues with regards to heavy metals or other contaminants in the concrete? Food security is important, but long-term health costs are also necessary to consider. Thanks!

  6. I too have a deer problem and have resorted to raised beds in an effort to eliminate the nuisance. Do what I finally did and make some hinged lids framed out of 2×6 with chicken wire stretched tight over the top. No more damned deer, or squirrels, or birds, or ……………………

    1. I would like to see pictures of the covers that you made for your garden beds. I have raised beds but my husband and I are thinking of making a screened covers to try to keep the bugs off of the veggies. We have deer but our biggest problem are the stink bugs. I am hopping this would help. If you could respond I would be greatful. Thank you.

  7. GREAT IDEA! One thing to add, I am planning on constructing a raised garden (with some help!) this spring. I worked as a landscaper for 4 years when I was younger and learned a bit about sprinkler systems. For my garden I am planning on running some 1/2″ pvc, with holes drilled every 6″, smaller diameter working to larger diameter towards the back of the garden, about 6″ under the surface of the soil. I am planning on making an improvised rain catch to water it with (primarily). The lattice of pvc under the soil, I think, would make watering a little easier and could possibly “stretch” limited supplies if need be.

    As far as having trouble with deer, my grandparents live in MD and have had trouble with deer for as long as I can remember. My grandfather says that a ping-pong ball filled with coyote or fox urine strung in trees around the garden will keep them at bay. Also, they have always had bees (they have operated a “bee farm” since before I came along), just my observation, the deer never seem to go for the veg growing within 100′ of the bee hives. I don’t know if anyone is interested in keeping a few hives but the products (i.e. wax, royal jelly, honey, ect.) may make good trade items after TSHTF.

      1. KMart or anywhere hunting supplies are sold. They typically carry fox urine during deer hunting season because hunters use it on the bottom of their shoes to mask their human scent. I was told to be veeeery careful with fox urine because if I got it on my clothes, I would have to throw them away.

        I lived in the city and had gone looking for fox urine to keep raccoons from coming into my town garden and decimating my fish-filled water garden. It wasn’t deer season, so I never got the urine. I ended up buying one of those ultrasonic animal repeller thingies. I set it on a stone facing over my small pond/waterfall and toward the back alley wall that I knew the raccoons scaled. I connected this ultrasonic thingy to a dusk/dawn timer before plugging it into an outdoor electrical socket. This way it was off during the day when my small dog and I might be outside, when the raccoons were hiding anyway.

        All ultrasonic thingies said “not guaranteed to work against raccoons,” but whatever one I bought worked like a charm for years and years and years. No more destructive raccoons.

  8. We use old newspaper for weed control, etc. Helps hold moisture in during hot times and makes excellent cover for soil. At end of season we shred it up and mix into soil for compost. Great for flower beds if into that, cover with mulch for better control, etc. Excellent idea and layout. We also use rain water collected as water supply, small 12volt rv pump to push to plants by hose.

  9. That looks fantastic!
    If possible, could you give me the measurements of the growing space and also how many blocks you used?

    I am hoping to make 6-8 of them !

    1. I think the blocks are 16″ long and you can roughly count out how many I have there. For the width, I didn’t want to exceed 4′ across for ease of weeding. Also, don’t make them as high as I did in this instance. It’s overkill and you don’t need the soil that deep. Now I bury the first row of blocks and have the 2nd row sitting above the soil with the flat blocks across the top. That’s plenty high and it’s easier to maintain appropriate water levels.

  10. Dear RangerMan,
    Thanks so much for the details of cinder block building – I have a question about gophers…do you put aviary wire on the bottom of the bed before the fill soil to keep gophers at bay or is it a concern.
    Alex

    1. That crossed my mind, but I decided not to. The bed has a layer of blocks below grade, so that offers a little burrowing protection. I had a 6′ fence surrounding the beds to keep deer out.

  11. I have tried a poor man’s verion of this with scrap lumber. And for the bottom of the bed I put that fabric down that you use to keep weed out of your flower bed . It did a good job of draining and keeping out the black berries.

    1. I can’t get a grip on what to do with the bottom of the bed. Could/should I dig up the grass, turn it over turf down and put the screen bedding on top then add my dirt? I am old, don’t really know what I’m doing but really want a garden!

      1. you can easily do this alternative. Instead of having the problem of the grass or extra material/chemical expense at the bottom of the planter. Try laying out black plastic covered with bricks at the ends and sides to keep it down. The heat from the power of the sun will kill off the grass or weeds below. Lift it up when you are done.

    1. Pick up a couple of Earth Boxes for your suburban gardening needs. They work well, good yields, and super easy.

    1. I didn’t know about the rosemarry . I have some I wonder if I plant it n the block holes would it b ok all winter long ? I could do that with the sage and such as well .

  12. I just scavaged 18 blocks from my neighborhood last night . Maybe I need 2 grab a few more & make my garden longer . I dug up the dirt nside the the blocks & I have a little bit of planting soil , but not a lot od $ . I am only going 1 bock high , but I think that will work 4 me . Thanlks 4 the info !

  13. I’m in the process of building a bed using concrete blocks. The dimensions will be 14ft long by 3.75ft wide. Initially I was planning on using concrete on the bottom row and mortar in the blocks. I am now wondering if this is necessary.

    Anyone have any thoughts or comments? I understand the costs involved, but otherwise, what are the pro’s and con’s. Thanks,

    1. Concrete on the bottom row and mortar in the blocks is definitely not necessary. Try it for a year just dry stacked and you’ll see for yourself. They don’t move much and it’s convenient having them dry stacked in case you ever want to move the bed.

  14. Rangerman,
    How deep do you set your first layer of blocks? and how high does your box end up above grade, with the caps in place?

  15. Great post – I found your site looking for cinder block raised beds. Did you have to use sand under the first layer of black to level? Thanks!

  16. Ranger man. Ron Hood here. Just saw your raised concrete block garden. I am thinking about having one like yours only about half the size. What do you think a contractor would charge to complete it?

    Ron Hood
    Owasso, Oklahoma

  17. It is really a fabulous blog. Content of this blog is so nice. This is a nice concept of gardening. I am so glad to go through a wonderful article. Thanks for sharing a fabulous blog……………..

  18. you are just a dream come true.at 89 i’m still gardening and is hard to bend over.so I was thinking of cement blocks and was looking for info .Thank you so much .
    Monique

  19. I live in the wilds of the Idaho mountains. I have been wanting raised beds for years. I think the concrete block beds are the answer. We have a deer and gopher problem. Hoping this will be the answer…it could easily be fenced and bottomed with some kind of wire.

    Thank you!

  20. Just what I am planning on doing – concrete raised garden bed. Thought I would plant some flowers in some of the holes. Only going two rows high – suppose I can always add a row later on. I like the idea of pvc for adding some protection (sun can be pretty hot here in the summer). For your deer problem add strips of Irish Spring soap – sounds strange but it works and is relatively cheap. You will need to replenish after a rain.

  21. Dear Ranger Man: Thanks so much for your very helpful blog and photos! Your foundation appears to be actual dirt, where ours in Albuquerque is limestone rocks, some caliche, and pure sand. If I build my raised bed 5 blocks high, and put our limestone rocks in the hollow blocks in each row for stability, do you believe that the weight of all those concrete blocks and rocks would cause the sand under the foundation to collapse? I’ve had suggestions from others here, that I should put concrete under the first row of cinder blocks (below ground level), but I don’t see how that would stop the entire thing from collapsing under the weight. As you said, we can’t put an entire concrete floor on this, there would be no drainage. Any comments would be appreciated, since I’d like to get this finished before it gets really hot here. Thanks!

  22. I am planning on a raised concrete block bed, was wanting to pull several blocks out and plant herbs in the single hole. How would you suggest covering the bottom so the dirt doesn’t fall out?

  23. Would it be safe to use scavenged (1920s-1940s) Cinder blocks, or should I buy new blocks for this project? Asbestos is a concern.

  24. Loved your cement block idea. Been planning one for 2 yrs and finally bought the blocks. In my 60’s and don’t want to crawl on the ground to weed any more. Making mine a bit taller and 2blocks thick, side by side. 12 feet long but only 36″ wide (short arms, don’t ya know) so I can weed without sitting inside to get the weeds in the middle. My back yard drops off to where 2 rows of bricks used to be, so I’m forced to make the side on the outside a retaining wall, 4 blocks high. then I can match it with the rest of the walls, 2 blocks high. Any good drainage ideas? I was thinking of using 1 foot of gravel, but I’m not sure what will happen when the dirt settles. My mother-in-law says to put down plastic over the gravel and then put holes in the plastic before adding the dirt. Also, do I need some sort of drainage tube network under the gravel? If it rains hard I’m afraid my plants will be floating. Any and all suggestions will be welcome. Thanks. Ps: I like the whole “greenhouse” effect with the tubing and plastic. Pennsylvania winters can be quite long and with that idea I can get a jumpstart on the garden without worrying about that “last frost” in late April or May. Thanks again, write back soon!

  25. Rangerman has done an excellent job of detailing a square foot garden, and as noted above, has made it fun. A standard building block is 16x8x8.To reiterate: beds don’t need to be more than one tall – if you wan to grow carrots, choose a shorter variety. For the lady having trouble bending over, elevated square foot beds are possible, a bit pricier and YOU won’t be able to build it. Google “images elevated square foot garden”. Gopher-guy: one recommendation includes laying chicken wire in the bottom, putting the blocks on the edge to hold it in place. Be sure to do that before you add your soil. Another recommendation is to add vermiculite for better drainage and easier root breathing. If you include 1/3 peat, 1/3 vermiculite and 1/3 compost, it costs a bit initially, but you never have to add peat and vermiculite again. Just goose up the nutrients each season with compost. Remember not to walk on or compact your soil – that’s why Rangerman says not more than 4 feet wide – you want to be able to plant, and pick, without stepping on your soil. You are growing your own food, man, give it your best – and ENJOY!

  26. With havin so much written content do you ever run into any issues of plagorism or copyright violation? My blog has a
    lot of completely unique content I’ve either written myself or outsourced but it seems a lot of it
    is popping it up all over the internet without my
    agreement. Do you know any solutions to help protect against content from being stolen?
    I’d certainly appreciate it.

    1. I’m so glad I found this site! I’m 73, disabled with arthritis, but have had many gardens in my lifetime, and I’d really like to build my last one as a legacy.

      I’ve recently found someone with many blocks and wood planks that had been used for shelving. She’s giving them away, and I’ve asked her to save them for me. I’m moving into a shared housing situation that has a huge garden, with no trees, in full sun. When I saw that, I visualized a raised bed garden of veggies and berries.

      My new landlady is all for it, so I just need to gather some strong helpers to transport the blocks and wood, then find people to help put it all together. You’ve made it easy with your pictures and instructions.

      I hope to provide enough food to share with other low income seniors and families in Petaluma, CA. Once the heavy rains subside, and I’m settled in, I’ll begin to draft a diagram of what and where things will go.

      Thank you so much!

  27. I just realized I said the yard had a huge garden, but I meant it’s a huge yard, ready for my dream garden with raised beds. A few fruit trees and some flowers might be nice if I can find any on Freecycle in the future. I can dream can’t I?

  28. You actually make it seem so easy with your presentation but
    I find thgis topic to be really something which I
    think I woulld never understand. It seems too compex and
    very broad for me. I am lookiing forward for your next post, I will try to gget thee hang of it!

  29. Nice post. I learn something totally new and challenging
    on blogs I stumbleupon on a daily basis.
    It’s always exciting to read through content from other authors and use something
    from other websites.

  30. Hey I am so excited I found your blog, I really found you by accident, while I was looking on Bing for something else, Nonetheless I am here now and would just like to say thanks for a marvelous post
    and a all round thrilling blog (I also love the theme/design), I don’t have time to go through it all at the minute but I have book-marked it
    and also included your RSS feeds, so when I have time I will be back
    to read more, Please do keep up the fantastic b.

  31. We used the very first 50% of the year questioning why Blizzard hadnot added its wildly
    popular card challenge to mobiles, and the second half not
    being able to put down our iPad as-usual, the
    sport arrived with Blizzard levels of gloss, making it a sudden and well-deserved challenger for mobile
    game of the entire year.

  32. Thanks for a marvelous posting! I genuinely eenjoyed reading it,
    you happen to be a greawt author.I will bbe sure to bookmark your blg and definitely
    will come back very soon. I want to encourage you to ultimately continue your
    great posts, have a nice evening!

  33. Can I simply say what a relief to uncover someone that genuinely knows what they are talking about over the
    internet. You certainly realize how to bring an issue to light
    and make it important. A lot more people have to check this out and understand this side of
    your story. I was surprised you are not more popular
    since you surely have the gift.

  34. We stumbled over here coming from a different website and thought I should check
    things out. I like what I see so i am just following you.

    Look forward to going over your web page again.

  35. Current technological changes that are so good make it easier for us to get the best variety of information on online sites like this. Seeing a website with such interesting content will make everyone stop and leave a message here.

  36. Superb blog! Do you have any recommendations for aspiring
    writers? I’m planning to start my own blog soon but I’m a little lost on everything.
    Would you recommend starting with a free platform like WordPress
    or go for a paid option? There are so many choices out there that I’m totally overwhelmed ..
    Any suggestions? Thanks!

  37. SEO make use of each of the combined techniques of keyword analysis, smart code, good content literature, building links study and website organization to position the
    niche web site as high as possible inside the list of search engine results browsing engines.
    These variables can include settings back,
    along with how your ads and keywords are being used, and
    staying in touch currently on changing algorithms so you know how you can adjust your ads and account settings to
    stay with a consistent trend with your earnings.

    These people went everywhere they can, and also the remaining
    portion of the Internet world soon followed.

Leave a Reply

Your email address will not be published. Required fields are marked *