I wanted to build some simple, low cost & attractive containers for a few fruit trees that were ready to be replanted in my backyard. Using second hand 55 gallon food safe plastic barrels and some scrap wood that I cleaned up on the planer, I was able to create some very basic planters for my backyard garden. The wood was free and the barrels were purchased off of craigslist for $10 a piece.
The project came together in an easy afternoon at the shop, and what's best, I got to use my brad nailer for the first time - bonus!
Inside the containers I planted a black jack fig tree, meyer lemon tree, and an unknown varietal of avocado that I started from seed 6 years ago. All in all, I think they really spruce up my backyard.
Step 1: Source a plastic barrel
I was able to find cheap and clean used barrels all over craigslist. Although you could use a steel drum as the structural container you wouldn't be able to use the brad nailer to affix the decorative wood slats - half the fun of this project, so I opted for plastic barrels which were cheaper and widely available used online.
I paid $10/barrel and bought two of them, one blue and one white, from a nice guy who was using them as rain barrels, but had just upgraded his system to something larger.