Vineyard posts break because they rot off right at the ground level. They are pressure treated and they usually last for at least ten years, but our vineyards are now mature (we started planting in 2002) and the posts still have a finite life. Then, if we are just a bit off when we approach the row with the harvester, it is easy to graze an end post and that is just enough to break it off at the ground. Getting a broken post out of the ground involves a lot of “elbow grease.” We dig down with a shovel far enough that we can get a grip with a chain on the remaining stump. We then pull it out with a skip loader and replace the broken post with a new one. By the way, the end posts are six inches in diameter and are initially pounded four feet into the ground.