I am thinking of using raised beds for my garden this year, I would like to
put several in before the start of the growing season. My question is what
to make them out of?

I went to a local firm that makes concrete blocks, and bought
"defective" blocks for fifty cents apiece. With slight cracks, they
wouldn't be safe for building foundations, but they work fine for
raised beds. I used two courses (layers). among other things, that
provides a nice bench around the bed to sit on when I cultivate, pick
lettuce, etc.

vince norris