raised garden beds
 

I'm going to be putting some raised beds in the vegetable garden. I'd like to use standard 8x8x16" concrete block dry laid, three rows high, with rebar pins. My sister has similar beds two rows high and hasn't had any problem with the rows getting out of plumb. Has anyone gone three rows high? I'm concerned the additional dirt might force the rows out of plumb.

Thanks,

It would probably depend on your soil type. The lightweight sandy and loamy soils being less likely to put much side pressure on your blocks compared with the heavier, expand and shrink, clay soils. Also place your rebar pins next to the inside interior of the block so any outward pressure presses directly against the rebar.

Myself, I don't bother with blocks to shore up the sides of my raised beds. I prefer a more flexible raised bed arrangement with mounded sides that I can plant to take advantage of their south and north facing slopes with their microclimates to speed up or slow down crop maturity. This is especially noticeable with strawberries where the earliest berries come off the south facing slope of the raised beds and the last berries comes off the north facing slope. Going block-less also allows you to easily shift the side of a bed if you decide you need a wider path or a wider bed in that location.

I have worked with 3 block raised beds before in a community garden. We filled the beds with almost 100% compost, so it was very light but had trouble retaining water. We did as basjoos suggests and staked rebar on the inside pf the blocks. Two years in there was no trouble with walls shifting.

That said, I now also build wall-less raised beds. However, these are not right for all situations. If you are putting beds in an existing lawn where you will keep most of the lawn, use the blocks or some other wall to help keep the grass out.

We've got raspberries, blueberries, etc. in mounded beds and that's working really well. The raised bed are for other, mainly shorter, crops I'd like to keep free of grass and weeds. And if I'm putting in raised beds I figure I might as well make them high enough to make my back happy - hence my question about the stability of a bed three blocks high. It seems it's been done with no problems so I'm planning to go ahead. Three rows high with rebar pins set towards the inside.

Thanks for the help everyone.

and massively expensive in most locations. block work was way cheaper here and we're in the middle of a major logging area where cedar is common.

I'm finally getting around to working on the raised beds.

The first of three is nearly done.

http://i194.photobucket.com/albums/z...den/r_bed1.jpg

I'll be packing gravel around the rebar pins to (hopefully) keep everything aligned.

http://i194.photobucket.com/albums/z...den/r_bed2.jpg

Did you glue them together?

Now put rotten wood or wood chips in to hold moisture/ feed your veggies. raised garden beds: hugelkultur instead of irrigation

No glue. Dry laid.

Most of the dirt is in now along with some seaweed.

http://i194.photobucket.com/albums/z...ps5e0579c5.jpg