Completed one planter today out of the 5 I am building. I'm experimenting with utilizing Doug Fir covered with plastic on the inside instead of redwood. The Doug Fir 2X12s are less than a $1 a linear foot. While not as rot resistant as redwood, actually not even close, I'm hoping the plastic will help me get somewhere near the same life span. If not I'll replace it with redwood or manufactured lumber at a later time when the Doug Fir is rotted away. This planter is a 3'X8' that I am using for herbs and a bee garden. It gets 4 hours morning sun and 3 hours late afternoon sun. The other planters will be a 3'X4' located in midday shade also that will be used for lettuce, radishes, and carrots as well as 3 - 4'X10' planters in direct sun all day. These will go into rotation with my fence planters and my 20'X20' garden area.