With this new corner brace, I expect the end boards will last considerably longer than just bolted wood. Time will tell.
I have been using raised beds for several years now. I converted an existing patch of grass into four, 4ft x 12ft raised beds for a total garden area of 192 sq. ft. This could, conceivably, produce enough food throughout the year to make a serious dent in the food budget. And, of course, all the advantages of raised-bed gardening are realized. However, I have had to replace several end boards due to rotting out at the corners. In order to prevent this from happening, I came up with a way to use concrete as a corner brace, and thereby stop the rotting and make a more permanent installation. Starting in step 7, I show how to replace an end board that has rotted out at the corners.
Step 1: Materials Needed
The usual concrete tools, materials and supplies. For my mix, I used a ready mix concrete so that I would be sure to have a uniform, strong concrete. For the bed itself, I choose to use 2x dimensional lumber. At least one bed is made with 2x12's, one with 2x10s, and so on. A 2x6 is certainly big enough, so it is a matter of personal preference. In this instructable, the lumber is 2x8's.