I have two short raised beds made of cinder blocks (8 in. and 16 in. tall) that isn't finished yet. I was wondering if it's okay to fill the voids of the blocks with excess soil from my yard? I live in a country where it never goes below freezing so I don't need to worry about moisture freezing and cracking the block. I've heard that soil inside a block can cause a moisture issue. But, it's being used as a retaining wall so it will have moist soil in contact with one face of the block always. What is the difference between this and having the moisture inside the block? Will filling them with soil causes the blocks to degrade faster? Is there even any structural benefit in filling with soil?

2 Answers 2


Many of the blocks used for retaing walls are filled with dirt so I don’t see an issue. In fact, some are designed to taper back and provide planting space.

And my neighbor has just put one up which still has lots of moisture in it with temperatures well below freezing... nothing cracked yet...


It wouldn't be recommended if you are in an area where it will freeze. The dirt will hold moisture, and when it freezes could split the block. Really not a big deal for a planter bed, but it can happen. If it never freezes, have at it, it will not be a problem.

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