Polymerous - Thank you for your insight and experience! Your comments and drawings are very helpful and worthy of consideration for anyone thinking of building a raised bed (regardless of what material you use).
The key-hole bed design has worked relatively well for me. I can reach into every part of the raised bed because of the short walk-in area. But you are correct that some areas are not as easily accessible in many designs. I also chose not to put a ledge on my bed frame. I had used cinder blocks w/topper blocks on a previous bed which made it wide enough to sit on while weeding. But on the key-hole bed, I didn't want the wide cinder blocks to take up additional planting area, so instead used the narrower pavers which worked well for me. This is just a personal preference.
Probably the best design would be a long, straight 3'- 4' wide bed that can be accessed from all sides.
In my article, it really wasn't my intention to promote the key-hole design. My article was sharing my experience using 12" square pavers to build and form a raised bed. Wood just does not last very long at all for me here in Florida. 16" square pavers would also work, but they are heavier to lift and keep in place while the adhesive dries.
I have had great success using the concrete pavers for a raised bed frame. I also like cinder block to frame out a raised bed as well. As you might have read in a previous article, I have used a variety of concrete pieces to build numerous raised beds and have eliminated most of the wood structures in my garden.
http://garden.org/ideas/view/b...
