[pelling]

Hi everyone.

I am new and have a bit of an odd question: has anyone used concrete blocks stuck with grip adhesive to make raised beds?

I have an allotment and due to health issues plan to make 2 foot deep raised beds for most of it.  After pricing up various alternatives I am seriously looking at using concrete blocks.  I was initially planing to lay them on their sides in dry stone wall style, but unfortunately in this area they would soon be stolen.  My fiancee then suggested no nails, which would make them harder to pinch and possibly allow me to lay them the normal way up, reducing the number of blocks needed and the amount of waisted space.  However, is even exterior grip adhesive up to holding concrete blocks together as well as the wait of the soil?

I am planning to build the beds roughly 4 foot by 20 foot, but in sections 4 foot square for extra strength.

Any thoughts, suggestions, ideas, very welcome.

[Trillium]

More folk than you realize use concrete blocks for raised beds. The blocks don't have to be 10 or 12" wide, as 6 or 8" will do fine. No need to go terribly high either as few plants root that deeply. 2 or 3 high would be adequate.

I'd not make the beds so long as it's a pain having to walk around that length to reach something on the other side. Better to stay with something like 8 ft beds or so.

I used a special concrete adhesive that comes in caulking tubes and it works fine. I also set in some remnant rebar and/or pipes inside the walls to help stabilize the blocks. Some folk fill the block 'holes' with soil and plant small crops like herbs, but I just filled them with pea gravel as I don't want to risk freezing soil splitting my blocks.

Here's more info: FgEUc00DzLANR=1&feature=fvwp

There are more videos here if you enter variables of cinder block garden beds, etc.

[LittleRedHen]

I've had a rather large raised bed made of concrete block.  I did not use adhesive between the concrete blocks.  It worked brilliantly, but I had weeds growing out of the cracks between the concrete blocks.  They weren't difficult to pull out and the nooks and crannies made wonderful homes for everything from newts to toads.  Of course there was the year that the wasps thought it was a brilliant place for a nest.  That was the down side.  Mind you, it only happened once out of over thirty years.

[Growster...]

I'd have thought 6" blocks, laid stretcher bond would work, if about 2' high, and have you thought about a foundation at all? You could get away with a block laid sideways for this, but the ground would have to be dead level.

Is it not possible to use ordinary mortar?

[Trillium]

There's no need for foundation work with raised block beds. Doesn't matter if it sinks a bit because the rest of the wall will continue to support itself and you do want soil anyway.

I'd never use mortar as these are not permanent walls. I use the adhesive with mine because I tend to lean over them and the caulk keeps them steadier. If or when I no longer want the beds, they're easy to take down with a chisel and a few whacks rather than fighting with mortar.

[pelling]

Thanks everyone for the advice.  I think I'm going to go with trying the adhesive route.  Unfortunately, not fixing them in any way isn't an option as they would be stolen before I've got the beds finished.

I will keep you posted how it goes.