View Full Version : Concrete Block Raised Beds

06-02-2011, 03:40 AM
Hi, I'm new to these forums. I just found this site tonight. I like what I see.

I am building raised beds for my vegetable garden out of concrete blocks. I have already purchased the blocks and have them sitting in my yard near my garden. My soil is poor, lots of clay and not much drainage. This horrid wet spring has pushed me into making the beds. I've improved the soil the previous 3 years I've been here, but it's still not what I want and do not want to pour any more money and effort into the ground.

I have a good plan for the beds. The problem is that my soil is still quite wet. We are supposed to get a whole week with no rain, so I can get the bed done on Tuesday when my son comes to help.

My son is a mechanical engineer and construction major. So we're having a rather large debate about how best to put in the blocks. He wants to do this huge level foundation of the whole garden, trying to compact and level the entire area. I want to basically level the garden, but not put a layer of rock or sand on it. I want to dig shallow trenches 2-3 inches deep and fill with sand to lay down the blocks and level them.

I'm using 8 x 16 blocks, 2 high, so my beds are about 16 inches high. If they're 1-2 inches below ground, I'll still have a nice 12-14 inch depth of good soil to plant. I'm not using any mortar. Blocks 2 high should be heavy enough to hold the soil without falling over.

Tell me what you think.

11-14-2011, 02:24 PM
I know this is a little late, but will answer for anyone else having the same problems...

It all depends on the size of the area you are working with.
You will need a basic foundation if working with a very large area, so I feel that your son is probably correct.

It may seem like a lot of work but will save years of hastle if you end up with a lop-sided garden!

Mr Yan
11-15-2011, 12:01 AM
I never saw this thread either.

I have done several ornamental raised beds with concrete blocks. I dug a trench the depth of the bottom block. Back fill that trench with pea gravel and or sand such that the block will be buried half way when placed. If you're a bit OCD like me put a bubble stick over the block and make the rows dead flat and level to the world. Tap each block down with a mallet and move to the next.

There is a nice product by Quikrete to make dry-stacked (without mortar) block solid and remove the block lines called Quickwall.

I would not pour a foundation or compact a layer of sand and lime under the garden for drainage reasons. A better route would be to mix sand and organic matter into the native soil then build your garden soil compost mix over that.

Two of my main theories are NEVER to walk on or in a raised bed and not to stop roots from going down deep by putting weed fabric or sheeting at the bottom of the beds.

04-19-2012, 07:42 PM
I recently built a cinder block raised veggie garden bed and so far, am pleased with the results.
We removed the grass from the area we wanted to build the bed in, scraped away some dirt under each
block as it was laid to level each row, put a layer of weed protector in each section before adding the dirt,
and installed a drip irrigation system (from a starter kit purchased at Home Depot).
We didn't cement/mortar the bricks together - alternating them as they were stacked seemed to stablize each layer.

I'm concerned about the bed drying out easily so maybe shoud have put in a layer of plastic along the outside walls
of the whole structure but this was my 1st attempt at a raised bed - so I'm learning as I go.


07-22-2012, 11:28 PM
Hi. This year I decided to try raised beds for several reasons, poor soil, gophers, and weeds just to name a few. My husband made me some beds out of redwood two by fours. I ended up, however, with more plants than beds. Not wanting to spend a lot of money, I looked around the property (acreage seems to attract "stuff") to see what was available. Some how we seemed to accumulate quite a few tires over the years. I figured it couldn't hurt to try, so I stacked them three high and in went the tomatoes and cucumbers. So far they are doing great, and an added plus is recycling the old tires. I know not everybody has tires lying around, but if you visit a tire shop they are often more than happy to give you some they had to dispose of anyway! And if your so inclined, you can always find tires on the side of country roads. I know, I live on a back road, and it seems sometimes people think my street is a dump site. For pictures of my tire garden, visit my blog at www.fromtreestoweeds.com