A surprising discovery for the backyard raised beds

We’ve been planning on raised beds all along in the backyard running along almost the entire length of the northern fence. This is partially because it’s easier to tend a garden when you don’t have to get on your knees to do so, and because we want fresh new soil for planting things we’re going to eat, rather than the paint chips/construction debris/polluted soil that’s currently there now.

But what to build the raised beds out of? Our basic qualifications are that it needs to be relatively cheap, not require total replacement in less than 10 years, and be aesthetically pleasing and jibe with the overall project.

These qualifications did not lead us where I thought it would as far as materials go.

When we first started talking about this, of course Rachel suggested stone of some kind, and though I certainly loved the look of stacked stone of some kind — like a flagstone bed I saw a friend of mine build on his own over on Capitol Hill — I also just assumed that stone was likely to be much more expensive than wood, and on a project where we were cutting costs everywhere possible and doing as much work as we could by ourselves in order to realize as much of the whole vision, it would be a little out of reach.

Pressure treated wood was out, because I don’t want those chemicals near food we’re going to eat — no matter what the EPA or whomever else says about how safe they are. Which really just left cedar, redwood or some other untreated ultra-hard wood as the only other option.

I started pricing Western Red Cedar after doing some research, and after discovering that 6×6 timbers like I used for the retaining wall were more than three times the price of their pressure-treated counterparts, I realized that this whole bed was going to be crazy expensive, right? Even 2×6’s and 2x8s combined with 4x4s as corner posts was more expensive than I anticipated. And even with cedar, left untreated and up against perpetual moisture, they’d have to be rebuilt at some point in 7-10 years.

So I started thinking about stone. I wanted something that a) wouldn’t require mortar (I’m no mason) and b) wouldn’t break the bank. Doing something with real flagstone or the like would be far too expensive — while my friend’s bed was a small corner of their narrow yard, this bed in our yard is going to span more than 25 feet, which means a lot of stone.

But is there something that’s not expensive cut stone but similar? With just a little bit of looking around, I started to see good-looking applications with these pretty common stackable concrete blocks.

They’re trapezoidal shaped, which means you can create curved walls without having to buy “corner” blocks or using masonry tools to cut them all down. They have a lip on the back, which provides the ability to hold back dirt as a retaining wall or bed up to a certain height and they come in a nice variety of colors and shapes.

The same manufacturers also make matching smooth concrete caps to go on top to give the walls a nice finished look. (While they say you can just dry-stack everything, I’m going to use some masonry adhesive on every run to ensure they stay together.)

Because we’re taking the raised beds from 3 feet wide down to 2 feet around where the walk runs into them (to provide for more patio space), having something that gives me the ability to curve is really going to add a nice flourish to the project. You can see the general feel in the photo from the roof with the beds sketched in at right.

But best of all, as I started calculating how many blocks I’d need (using cinder blocks for the back wall against the fence where no one will see), I was more than a little shocked to find out that using these stones instead of cedar could be a difference of as much as $400. The stones come in different prices, of course, and on the cheaper end of the spectrum, I figure we can do the entire raised bed for about $350, plust the gravel and sand for the base.  Cedar was going to run at least $600 for 2-inch-thick walls, as much as $750 or $800 for 4x4s or bigger. And they’d have to be replaced in a decade or less.

We have a winner.

So where do things stand on the whole project? The retaining wall is finished and the yard has been filled in and graded out somewhat.

I’ve finished talking to contractors for the pavers, and I think I’ve decided who we’re going to use, though we haven’t quite decided if we’re going to do the walkway and the patio now, or just the walkway now (which will almost totally be covered by the DC grant program) and then the patio later on, potentially on my own. The likely paver contractor won’t do the work until November after the fence and beds are already done — he’s too busy right now.

My friend Kurt is going to get started on the fence in mid-October, as soon as he gets himself married next weekend and enjoys his honeymoon. I’ll likely wait until he finishes the fence before ordering the stone and building the raised bed so I can get it as close to the fence as possible, though I may do all the excavation work before then.

I have to do some digging in any case to remove the last of the concrete from the left track of the driveway — I realized that it would get in the way of a) the fence posts, b) the base for the stone walls, and also c) any roots for plants that want to go deeper than 16 inches. Which means I’ll be back out in the yard with the pick and the sledge, breaking up another 50 square feet of concrete soon. Yay.

One thing I won’t have to do, though, is get rid of the last of that enormous pain-in-the-ass stump that was in the way of the bed. That bad boy came out on Sunday after lots of digging, picking, sawzalling, chopping and prying with an old fence post.

So whaddya think? Concrete blocks a good idea for the raised bed? Surprised that they’re so much cheaper than wood?