How long do you typically expect black locust to last in a fence?
I don't have an average lifespan, but there are posts in a fence my Grandad and Dad put in during the early 1960s that are good and solid. The terrain was hilly well drained soil. Some posts have been replaced and the common theme there was the posts had less than 5"-6" of heartwood. My Dad and I put in a section of fence with 11 T posts spaced then a locust post, then 11 T posts, etc., and locust was used for corner and brace posts. That was 37 years ago and not one locust post has been replaced.
