Well, as I’ve continued to build raised garden beds, I’ve tried very hard to limit myself to recycled materials. Unfortunately, the conditions in my back yard, in which rocks, gravel, sand and clay imitate some large and unfriendly layer cake, serve to reduce my chances of success following this approach. Having initially planned to follow the plan of my brother, developed and implemented by himself in Denmark- building beds without hardware, using two-by-four stakes to hold up the sides of the beds, I dug holes for stakes with great difficulty. My post-hole diggers, so useful in California, sit untouched in the garage because post-hole diggers depend upon soil that is made up of mostly soil (rather than mostly rock as in our case). With considerable labor, I can produce holes that are adequate generally, but which are just a little too shallow to hold the stakes vertical when bearing a load.
Backup plan number 2, involving rebar stakes, when safely executed, requires just as much hole digging in reality. When unsafely executed, purchase of an abundance of not-locally produced bandaids becomes necessary (plus the rebar and plastic caps for the rebar to prevent further industrial accidents suffered by unsuspecting individuals strolling out in the garden on some distant date after which the garden will be more a garden and less a construction zone).
Backup 3 involves lag screws purchased from the hardware store. Also some bolts, nuts and washers scavenged from our fairly well stocked garage. Using these with select power and hand tools, I was able to quickly knock together a sturdy box for my third raised bed. I’m so delighted by this that I must admit that I couldn't give a flying fig for where the lag screws came from. This is bad attitude I know, but whatever.
Next I get to dig out all the soil that sits under the box and get rocks out of it so that anything will grow in it.