[tallyho8]

I am in South Louisiana where the water table is high and fence posts will always be in wet ground. The landscape timbers sold here are all rated for above-ground usage and will rot out in 3 years if used for fence posts. I use 2 or 3" round treated fence posts sold at the feed store that are more heavily treated and rated for in-ground usage. They are about the same price which is a lot cheaper than 4x4s which would be better but more expensive.

Depending on the soil conditions in your area it may not be advisable to use landscape timbers.