I don't think pressure treatment will stop moisture wicking, it's still porous wood. In fact the landscape timbers around here specifically say "Not for Ground Contact", which is almost an oxymoron ;-) I use them on the ground anyway. They make terrible fence post, around here in wet areas they'll only last about 2-3 years.
Here on the farm we usually have quite a few dead Eastern Red Cedars. They use the bigger parts for fence posts and I've used a lot tops for firewood stack runners, they seem to last a long time, gotta few I've been using for about 20 years.
BTW: 2x4-8' are $2.97 at Lowe's here right now.
- #2 Grade allows wane and has a similar strength rating to #2 Prime lumber
- Pressure treated for exterior above ground use
- Treatment meets AWPA (American Wood Protection Association) standards
- Limited lifetime warranty that protects against rot, decay, and wood ingesting insects
- Easily painted or stained: recommended to wait 60 days after installation
- Hot-dipped galvanized or stainless-steel fasteners and fittings are recommended
- Safe for use around humans, pets, plants, and vegetables
- Specie of product is Southern yellow pine
- HT (Heat Treatment) on grade mark: wood is subjected to high temperature kilns before treatment
Landscape Timbers: $3.97
- Surface treated for cosmetic purposes; for decorative use only
- Not intended for ground contact
- Not intended to be used for fence post
- No warranty
- Easily painted or stained: recommend to wait 60 days after installation
- Hot-dipped galvanized or stainless-steel fasteners and fittings are recommended
- Safe for use around humans, pets, plants, and vegetables
- Specie of product is Southern yellow pine