Wednesday, April 29, 2009

Building a Cinder Block Raised Garden Bed

How to build a raised bed out of cinder blocks

Building a raised bed out of cinder blocks is easy and if you watch the local classified ads you can probably get the material for free (I did for this one). Also, cinder block raised beds have the added advantage of creating thermal mass which stores heat and warms the soil longer.

Here's a 4x5ft cinder block raised bed garden I built for a spice garden. Step one is lay the blocks in a rows.


Try to make the blocks level by clearing the dirt.


I wouldn't go any wider than 2 blocks and then the length is up to you. This one is shorter because I'm using it for a spice garden and then I want to trellis cucumbers behind it against the fence.


The holes in the brick can be filled with rocks, gravel and sand to create thermal mass for absorbing solar energy. it will help warm the soil and release it back later in the evening.




Some people also fill it with soil and plant individual plant in each hole. Plants that like to spread are great for this, plants like mint. etc...



Here we go, done and ready for planting.


I asked the kids to put the rocks they find in the holes, so it will take a while to fill, but the little ones always like something to do.




I'll show you how I used an old tractor tire in my next post.

Happy gardening,

--Greg

16 comments:

Anonymous said...

Cool. Thanks.

Anonymous said...

Greg,

Thanks for sharing the photos and lesson on the use of cinder blocks. My wife wants a bed next to the house (concrete patio) that can be wrapped in stucco to match as if the beds were designed as part of the home. I'm still researching, but, at first glance, it seems as though the blocks don't have to be mortered together or have a first run 6" or so into the ground. Also, a concrete bed doesn't appear to be necessary either. Now off to that research...thanks again!

Greg and Renee Rouse said...

Anonymous,

You're correct on not having a concrete bed, you want drainage and a slab would prevent that. Also you can mortar or not the higher you go the more you may need to, just make sure you stagger each layer. Another option is to hammer rebar through the holes for support. I would personally mortar if I were going to use stucco because they may shift and that would cause cracking of your stucco finish.

Shelley said...

We have major gopher problems and want to put welded wire under blocks (we use wire on all our wooden beds but it is attached). Should we just set blocks on wire? What do you suggest to keep blocks or bed from slumping if it gets undermined?

Greg and Renee Rouse said...

Shelley, one option is to put in a concrete footing around the base and attach the wire, but it's pretty costly. Another is to pound rebar through the holes to give a little more support to the walls and then fill the holes with concrete or not. And the cheapest is to wrap the wire up and over the outside of the first row of blocks and then place the second row over the top of the edge, trapping it between layers. I'm kind of frugal so the last one I like, plus if you need to move a bed it's easier.

Brian said...

Thanks for sharing your information about raised bed gardens. This a very thorough website. I hope this is considered appropriate. For people who may not wish to build their own, there is a ready to assemble raised bed garden available at www.best-raised-bed-gardens.com

Anonymous said...

Hi Greg! I found your site in a search regarding the newer concrete blocks being produced using fly ash instead of concrete. I am still in the beginning stages of my research. I was curious to know if you are aware of this problem. We just constructed a hoop house and were going to continue doing the raised beds inside like we have done outside using the block but now we're not so sure. Thanks!

Greg and Renee Rouse said...

Anonymous, haven't heard much about blocks made with fly ash, but please keep us informed of what you find out...

Rain23 said...

This is a great way to garden if you've got arthritis; getting rid of the stooping over so far really helps your spine and then the fun parts of gardening will draw you outside to get more exercise because it doesn't lame you up for 3 days afterward.

I especially like the way you involved the children. I will try this with my grand-nephew who loves to find rocks and is thrilled to help. What a good way to involve the whole family, even the ones too small to help construct.

Lynnda said...

I love the cinderblock garden idea, and would likely put wire mesh underneath and over the bottom row (filled with rocks for drainage)as we have a huge mole problem. Then a 2nd layer of blocks for growing, and deep rooted plants in the center of the square. My question is, how difficult is it to remove the old dirt and replace it with new fertile dirt (in the blocks and in the center)? Do you use a garden spade for the blocks? Do you remove one end of the blocks to till the center? any info would be helpful, thanks so much, the pics are especially helpful.

Jean C said...

I've had 2 beds like this in my backyard for 4 years now.
They are fantastic.
In the "holes", I have chives, mint, oregano, and thyme.
Every year, I plant the other holes with lettuce, basil, and marigolds.
Great way to build a raised bed!

Carol Soriano said...

How much soil did it take to fill the bed? Thanks so much:) Excited to try this.

Anonymous said...

Planting mint in the holes would be a bad idea unless you plan on your raised bed becoming a mint patch some day. It will take over the bed in a short time, the roots are fast spreading. When I bought my home in 1984 the previous owners had mint growing along the side of the house, it is now 2013 and after digging and digging I still get a few sprouts that come up every year. I suggest using wall caps, they are the same size as the top of the blocks and 2 inches thick and this will give you a flat place to sit and also allow for putting your blocks a few inches in the ground to anchor them without losing any depth in your bed.

Anonymous said...

I have used cinder block raised bed for about 25 years. I usually make mine a little wider than yours and also butt another bed next to it to save on the blocks needed. I just place wide boards over the blocks down the center to walk on. I plant herbs and flowers in the upright holes on the outer edges to keep them from wandering too far. I find that the lime in the concrete also helps with the garden. As far as I know there aren't as many problem as there are in raised beds using wood that rots or is treated with chemicals. Good luck all.....

Anonymous said...

Would the Cinder Block Raised Garden Bed be appropriate for a tomato garden?

Greg Rouse said...

You bet!