[Greenbuilding] best lumber for raised vegetable beds

[Chris Koehn]

Tim,

In my opinion the answer to your question depends on where you live. Out here on the west coast, 2nd growth western red cedar is most available and can be harvested sustainably. As previously mentioned, 2nd growth isn't as long-lasting as old growth but if you use heartwood it will last a long time. I've found that providing drainage helps as well.
Other species I've used for their rot resistant qualities include locust (black or honey), black walnut, and hedge (osage orange) and white oak (not red oak). Many urban foresters in areas of the country where deciduous trees grow have logs available for the hauling as it's usual fate is firewood. Some are networked with sawyers who can turn it into boards for you at nominal cost. I used to get free logs from city of Milwaukee arborists who were removing urban problem trees. Always had to check for metal before sawing but well worth the extra hassle. Worked with a few different Wood Miser owner/operators for the sawing. They used to keep a list of owner/operators on their website but it seems to be gone. Expect to pay between 40 and 60 cents per board foot for sawing (for reference, I pay $1.50 / b.f. for red cedar at the mill).
I'll do just about anything to avoid using chemically treated wood for anything and it should never be used in a garden. 

Chris
TimberGuides
Vancouver Island

Tim wrote:
"What type of wood, treated or otherwise, would y'all expect to last longest in ground contact when used to make raised vegetable garden  beds..?"