You can use just about anything as a planter, provided it can hold an adequate amount of soil, and that it can drain. When a friend was lamenting the untimely death of her mint plant, well before Mojito season, I decided to gift her some planted mint, with an upgrade. I planted the mint in its own pot, as it will strangle anything in a shared space.
I had an empty wine crate, discarded by my local wine merchant, and thought it would make a cute herb box as well. I drilled drainage holes in the bottom, filled it with soil and planted rosemary, sage, thyme and basil in the box, with little ceramic labels for easy identification.
While this herb box turned out to be really cute, it is an experiment with some inherent problems. The wood is thin, and may not hold up for a long time with wet soil in it. And, it is pretty heavy.
I’ll keep an eye on it to see how it fares, and replace my friend’s if need be. In the mean time, I think its pretty handsome.