Cinder/concrete blocks for raised beds, concerned?

So I’ve been away for some time as l had lost interest in this hobby.
Now it’s time to get back into the swing of things and this time I want to use raised beds instead of containers.

As you might be aware of the toxicity that cinder blocks leach into the soil, at least by what some individuals have speculated, but really no data to back it up. Perhaps it will raise the pH but I’m not concerned with that as there’s numerous ways to control the pH and buffering it.

My conclusion would be to buy the concrete blocks new and not use old cinder blocks that are light in weight, but again, I’m not totally convinced.

If you have any information that would persuade my decision, give the forum and myself some useful information that would help us make a better choice.

Thanks,
Ron

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I use them, but I only center-poured them with concrete; i.e., no grout between the blocks. This permits better drainage.

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Pardon my ignorance but whats toxic about a cinder block? As one of the most common building materials used in this country ive never thought of them as toxic.

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Probably have lead and other heavy metals form burning coal…but only if you are soaking many new cinder blocks into a Koi pond are they obviously toxic. Some residual toxins probably…but then again, breathing air may have residual toxins.

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Cinder blocks and masonry block are very different in composition. I am using the latter.

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I never thought of using them as a border for raised beds. Nice idea and they would actually look halfway decent and keep up with the weather, especially over the winters up here in Maine.

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They’re durable alright. Janet didn’t like the plain masonry look so I affixed outdoor slate tile to the top.

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just don’t fill the holes with dirt as it expands when it freezes, cracking them in our cold winters. fill w/ concrete or leave them empty and cover the top.

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A business near us has built a garden/picnic area for the employees and they put in these raised beds. The center is hollow for a compost chute. Some of the plants I’ve seen growing have been fabulous and are usually vegetables. They actually have an employee contest with a cash prize for the best “garden”.

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Too bad they’re not permanent structures!

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You have a swell back yard. Bet you can grow everything in California!

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I wish, but no. Black Currants and Cashews to name two.

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Cinder block topped with wood. Interior dimensions 21 by 3 feet.
raisedBedCinder

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how do you keep the wood in place?

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Every road in the country uses fly ash in the roads http://flyash.com/about-fly-ash/

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Decades ago, yes. Out here in the west it’s been replaced by rock dust from quarries and recycled concrete operations.

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Thanks for all the replies, it looks like it will be concrete blocks with wood planks on the top.

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The one thing I would be concerned about when you go this route is that you want a good seal between the wood and the tops of the cinderblocks. Otherwise you made really amazing slug habitats.

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That is great! They may not have wanted permanent structures . . . just an experiment. I love the PVC ‘rafters’ for bird netting - or to make a cold frame of sorts.
There is a fellow who lives near me, who took different colors of ‘pastel shades’ of paint - and painted each block a different color. It is very cheerful - and in the right environment would be a sweet way to dress up the block.

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raised beds

These are mine. I topped them with paving blocks. I’ve since rearranged them from 4 X 4 to 4 X 8 formats but the idea is the same. They work nice in my cool spring climate, warming up more quickly than wood sided raised beds. Peppers especially do well. Bought new, at about $1 a block, the price is right, too.

I never thought to worry about toxins. These were actually old blocks that I scrounged from various previous projects.

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