what is a good, cheap wood to use for outdoor planter boxes?
I live in Silicon Valley, CA and want to build a set of four 4'x1 1/2' planter boxes in my backyard that will have chicken wire underneath them to keep out gophers. I want to build them relatively cheaply, so I know that redwood is not really an option. Also, they will be growing food, so that removes pressure treated wood from the mix. However, I would still like them to last a few years. What kind of wood should I use instead? Is there some kind of paint or finish that I can use to increase the lifespan of the boxes without adding anything nasty to the soil (and by extension, my food)? Thanks for any help anyone can give me in this matter!