I use cedar for posts, Eastern Red Cedar. I can show you posts that have been in the ground for 70 years, and are still sound. Although I have used them as soon as cut them, I prefer to cut them in the winter when the sap is down, and let them dry for a few months. The redder the post is, the longer it will last.
Yep. The less sapwood (white wood) the better. You want the post to have as much heartwood (red wood) as you can get,
