Walled Garden: Cheap, Easy and Fast
You have to admit that this isn't your average garden wall. But think of it this way - it's fast to build. It's cheap and easy to build. And after the season is over, you can compost your wall to feed next year's crop of flowers or vegetables. Or, you can actually take it one step further and build permanent straw bale walls.
As I said, cheap, easy and fast.
I note this wall was in one of the gardens at FLORA, Montreal.