Sharon, my fiancee, is really into growing flowers. Her back yard though, has some weird slopes in it, so the drainage isn't alwasy what she'd like for some of the flowers. The solution for this is to construct a rasied flower bed. Guess who gets that job!
Anyway, it was summer, and I wasn't working at the time, so it was a good time.
I used that composite lumber that's mostly recycled plastic, with a bit of sawdust or something added so you can pretend it's wood. This stuff is very expensive for building a deck, but I only needed a few boards and a bunch of balustrade pieces for verticals. We got the treated decking screws and that's about it for materials.
I measured everything out and got ready. I bevelled the ends of the boards with a mitre saw so they'd meet at the corners, and I cut everything to length. I constructed the sides and ends separately, then assembled the box right next to where it was going to be. The verticals that hold everything together only stick out a few inches below the box, just to anchor the sides without having to drive these things deep into the dirt.
The tricky part is that the yard actually slopes in two directions in the place this bed went. Each wall has a custom height, and was partially dug into the ground and partially resting on the ground. The lowest corner actually doesn't go all the way to the ground, but has some bricks and rocks there to hold the dirt in. There are some bricks at other points to create a solid base.
Anyway, I vastly underestimated the weight of the dirt this thing is supposed to contain. I wound up adding reinforcements to the middle of the long walls, and a couple of extra verticals to peg those long walls in place. So far, it hasn't collapsed, but it will be a few years before it's filled all the way to the top.
The bed is filled with bulbs now, and we'll see how it looks in the spring when all the flowers come up.