Rick, putting plastic anywhere near my beds would kind of defeat the purpose of having a natural environment, ya know? I've got one bed that I made in summer 2008, and haven't noticed any issues with it. But I live near ATL, so we don't tend to have issues with dryness here.
The original owners had a raised bed in the back yard. They built the house in 1987 or thereabouts. The landscape timbers rotted out sometime in the last couple years. I think I'm safe.
