Greenleaf Forestry & Wood Products DOES NOT offer pressure treated wood, but we suggest locally applied wood preservative where it is needed (specifically where the wood can get wet from the elements).
If wood posts are going to be installed directly in the ground, be sure to liberally apply wood preservative to the butt ends to be in ground contact. The most effective chemical is copper napthenate, and it is available in concentrate to mix in diesel fuel and needs to be well soaked into the wood. A copper borate paste is also available and may work as well.
For best penetration, green lumber should be allowed to air dry as much as possible before applying the preservative. Use of tar is not recommended and it is far less effective than copper napthenate. This may take devising a soaking tub / barrel or repeated brush application. See www.poles.com (based in Manitou Springs, Colorado) for this material. Copper napthenate may be available premixed at hardware stores, sometimes called "Green Treat".
Installation of posts in concrete is not recommended, as it draws moisture to the wood and this causes rot. Packing loose gravel around and below the posts helps water drain away and prolongs post life, in combination with the wood preservative. Above ground fencing boards should not touch the ground, so they do not soak up water and rot. The idea is to keep installed wood as dry as possible, or apply wood preservative where moisture is likely.
Above ground portions of the posts and fencing boards can be treated with a true wood preservative stain, such as TWP-1500, available online at www.twpstain.com in several color choices. Note that commonly available stains are likely not to include a wood preservative and thus are not recommended.
Let us know any questions or clarifications needed.
