Finish the Box
Lightly sand any rough edges and corners to smooth out splinters. If you wish, you can stain, seal or prime and paint your planter to suit your home's decor. Because you used cedar, however, it can stay unfinished: cedar is one of the best lumbers you can use for exterior applications. This planter is a good size for potted plants, but you may wish to add a plastic liner and fill it with soil (add a layer of gravel first). If you do, don't forget to cut holes in the liner to line up with the drainage holes in the bottom of the planter.