Raised bed construction

This post goes out to my friend Carol Kizis in Buffalo who is thinking of starting to vegetable garden now that she has her ornamental growing down pat. She asked me about building raised beds and asked for some sketches so I thought that I would just do a post with picts to show her, and anyone else who’s interested, how I do it. First, let me say that I have been building raised beds for almost 35 years and I  have used a lot of designs. Even in my current garden I have several. But I now have settled on one because it is easy and cheap.

My beds are always 4 feet wide. It is the maximum width to work across and one wants to maximize bed space. My beds are also always 8 or 16 feet in length. Both of these dimensions take advantage of normal lumber sizes. My beds are made of treated lumber … if you are concerned about arsenic in treated lumber read this article from Fine Gardening.  It is fairly comprehensive. The bottom line is that migration of the arsenic from the wood into the soil is minimal and can be rendered inconsequential by a few minor cautions. Treated lumber has served me well for a long time and the beds last 20 years or so.

I now build my beds solely out of 8 foot treated 2 by 4s. The reason is simple … they are often on sale at the big-box hardware stores. You can build one 4′ by 8′ bed for the cost of 7 boards (plus a few 3″ deck screws). A 7 board bed is 7 inches high and has room to add another board later on as the bed soil level rises. Or you can build a 10 board bed that is finished at about 10 1/2 inches high which is deep enough for most anything you plant.

seven board bed - two beds joined

seven board bed - two beds joined

Bed made with 10 boards

Bed made with 10 boards

I cut one board in half for each of the end pieces but I  make sure that “half” is 48″ since this lumber is notoriously uneven in dimension. So, every one board high takes three boards … two 8′ boards for the sides and two half boards for the ends. Also, each bed requires one board cut into 2′ lengths as the upright corner anchors.

So, for a seven board bed, cut one board into 4 2′ lengths, two boards into 4 4′ lengths and make sure that 4 boards are 8′ in length.

I use a drill and 3″ deck screws to put them together. The end pieces and the side pieces are screwed together to form a box. The the box is screwed to the anchor post. Here is a picture of a corner with the screws.

Better view of anchor post

Better view of anchor post

If you are building a 7 board bed, leave room on the top of the anchor post for one additional board to turn it, eventually, into a ten board bed. See the seven board bed picture above.  When you have the bed assembled, set it in place and mark where the anchor posts go into the ground. Remove the bed and dig post holes to accommodate the anchor posts.  When the holes are dug, set the bed in place and back-fill the holes. You may have to dig a bit under the ends and sides to get the bed level. Once the bed is level, turn the dirt in the bed over and fill with other good soil/manure/compost.

I said I did other variations and here are some pictures:

Bed made of 2 by 12s - 16' long

Bed made of 2 by 12s - 16

Very (too) deep bed made of 2 by 6s - 16' long

Very (too) deep bed made of 2 by 6s - 16

If you have any questions, let me know.



One Response to “Raised bed construction”

  1. Our deck has hundreds of screws which must be sub-surface to use rental sander, but they won’t ***** back in | Totally Woodworking Says:

    […] Raised bed construction […]

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